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SD-22-05 - Plans - Non-Record - 0255 Kennedy Drive (3)
50' Wetland Setbac k Wetland A T y p e I I I 50' We t land Se tb ac k Wetland B T y p e I I I 50' WetlandSetbackWetland C Type III Existing Lot 1 Area = 8.9 acres "Lancaster" Area = 5.0 acres "Stonington" Existing Lot 2 Existing Lot 3 Open Land Area = 2.0 acresExist ing Pond # 1 Existin g P o n d # 2 Existing P o n d # 3 Lot 6 Park Area = 3.0 ac Lot 9 Are a = 1 . 9 a c Lot 8 Area = 4.6 ac Lot 4 Area = 1.1 ac Lot 5 Area = 8.83 acres Lot 5 Area = 9.1 acres Lot 7 Area = 2.44 acres 22 Units 22 U n i t s 16 Units 55 Units Lot 10 Area = 0.9 ac Lot 14 Area = 1.1 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 16 Area = 6.72 ac Lot 11 Area = 1.2 ac Lot 12 Area = 1.6 ac Lot 18 Area = 0.56 ac Note: Lot 12 & 14 permanent improvements are shown for schematic purposes 50' Wetland Setbac k Wetland A T y p e I I I 50' We t land Se tb ac k Wetland B T y p e I I I 50' WetlandSetbackWetland C Type III Existing Lot 1 Area = 8.9 acres "Lancaster" Area = 5.0 acres "Stonington" Existing Lot 2 Existing Lot 3 Open Land Area = 2.0 acresExist ing Pond # 1 Existin g P o n d # 2 Existing P o n d # 3 Lot 6 Park Area = 3.0 ac Lot 9 Are a = 1 . 9 a c Lot 8 Area = 4.6 ac Lot 4 Area = 1.1 ac Lot 5 Area = 8.83 acres Lot 5 Area = 9.1 acres Lot 7 Area = 2.44 acres 22 Units 22 U n i t s 16 Units 55 Units Lot 10 Area = 0.9 ac Lot 14 Area = 1.1 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 16 Area = 6.72 ac Lot 11 Area = 1.2 ac Lot 12 Area = 1.6 ac Lot 18 Area = 0.56 ac Note: Lot 12 & 14 permanent improvements are shown for schematic purposes 10' paved pathLot 10 Area = 0.9 ac HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-2 SITE PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 LOTS 13 & 15 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Lot 14 Area = 1.1 ac Lot 12 Area = 1.6 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 16 Area = 6.7 ac Lot 11 Area = 1.2 ac Gravel Wetland #1 Gravel Wetland #2 8 Spaces29 Parking Spaces 32 Parking Spaces New Bike Rack New Bike Rack Snow Storage Snow Storage Snow Storage Screened Trash/ Recycling Screened Trash/ Recycling 8' concrete sidewalk 10' con c r e t e s i d e w a l k10' concrete sidewalk8' paved path 5' concrete sidewalk 5' concrete sidewalk5' concrete sidewalk 5' concrete sidewalk5' concrete sidewalkLot 18 Area = 0.56 ac Snow Storage Note: Lot 12 & 14 permanent improvements are shown for schematic purposes Temporary gravel pedestrian path during construction New Bike Rack New Bike Rack Screened Trash/ Recycling Snow Storage, including temporary storage in paved areas Snow Storage Snow Storage 8 Spaces 9 Spaces 9 Spaces 7 S p a c e s 10 S p a c e s 8 Spaces 9 Spaces9 Spaces18 Spaces18 Spaces5 Spaces14 Spaces8 Spaces6 Spaces4 Spaces2 S p a c e s Proposed 124 Unit Building Proposed 127 Unit Building 5.6' setback New Bike Rack AMENITY AREA =585 sf AMENITY AREA = 3,200 sf AMENITY AREA = 580 sf AMENITY AREA =1,035 sf AMENITY AREA = 2,120 sf AMENITY AREA = 755 sf AMENITY AREA =8,694 sf AMENITY AREA 680 sf AMENITY AREA 580 sf AMENITY AREA = 955 sf AMENITY AREA = 1,185 sf 15" HDPE s=0.089New 1 5 " H D P E s = 0 . 0 2 1 New 1 5 " H D P E s = 0. 0 8 6New 1 5 " HD PE s= 0 . 0 39 New 12" HDPE s=0.06New 12" HDPE s=0 . 0 1 New 15" HDPE s= 0 . 0 1New 1 8" HDPE s= 0 . 1 2 New 1 8 " H D P E s = 0 . 1 0 7 New 18" HDPE s=0.033 New 15" HDPE s=0.01 New 1 5 " H D P E s=0.01 Ne w 1 5 " H D P E s = 0 . 0 1 New 1 5 " HD PE s = 0 . 0 5 4 New 15" HDPE s=0.02New 15" HDPE s=0.052New 15" HDPE s=0 .043 New 1 5 " H D P E s = 0 . 0 2 1 New 12" HDPE s=0.057New 15"HDPE s=0.01New 15"HDPE s=0.01New 12" HDP E s = 0 . 0 0 5 New 15" HDPE s=0.032New 15" HDPE s=0.022 New 15" HDPE s=0.026 Screened Trash/ RecylcingNew 15" HDPE s=0.006New 15" HDPE s=0.0 1 New 1 5 " H D P E s =0. 0 4 3 Ne w 1 2 " H D P E s = 0 . 0 3 New 12" HDPE New g a s s e r v i c e New gas serviceNew 12" HDPEs=0.03New Bike RackNew 12" HDPE s=0.057New 12" HDPE s=0.097New 15" HDPE s=0.091New Transformer New Transformer New Gas meter New Gas meter New gate valve, cap, stub, thrust block, and witness for 8" water main. New Hydrant assembly New 8" x 8" x 8" tee, thrust block and gate valve. New 8" water stub with cap, trhust block and witness New Hydrant assembly New 8" x 8" x 8" tee, thrust block and gate valve. New 6" D.I. Cl 52 fire and 4" D.I. domestic water service to building. Connect to Phase 1 stub. Coordinate with mechanical plans.4"6"New 6"x4" tee with respective gate valves6"4"New 6" D.I. Cl 52 fire and 4" D.I. domestic water service to building. Connect to Phase 1 stub. Coordinate with mechanical plans. New 6"x4" tee with respective gate valves New 6" PVC SDR 35 sanitary sewer service to building. Connect to Phase 1 stub. Coordinate with mechanical plans. New 6" PVC SDR 35 sanitary sewer service to building. Connect to Phase 1 stub. Coordinate with mechanical plans. New CB Rim 367.3 Inv. in 361.42 Inv. out 361.33 Inv. ud 364.3 New CB Rim 348.25 Inv. in 343.25 Inv. out 343.15 New CB Rim 353.8 Inv. in 349.05 Inv. out 348.95 New CB Rim 360.4 Inv. in 355.65 Inv. out 355.55 New CB Rim 363.05 Inv. in 358.3 Inv. out 358.2 New CB Rim 364.5 Inv. out 360.0 New CB Rim 355.15 Inv. in 349.78 Inv. out 349.68 New CB Rim 359.8 Inv. in 354.48 Inv. out 354.38 New CB Rim 364.6 Inv. in 358.84 Inv. out 358.74 New CB Rim 359.55 Inv. out 355.05 New CB Rim 356.7 Inv. in 351.95 Inv. out 351.85 New CB Rim 359.55 Inv. out 355.05 New CB Rim 365.75 Inv. out 361.25 New CB Rim 372.8 Inv. in 367.91 Inv. out 367.81 Inv. ud 368.66 New CB Rim 372.9 Inv. out 368.15 Inv. ud 368.9 New CB Rim 370.9 Inv. in 366.15 Inv. out 366.05 Inv. ud 366.9 New CB Rim 370.9 Inv. in 365.9 Inv. out 365.8 Inv. ud 366.65 CB#61 Rim 362.13 Inv. in 357.38 Inv. out 357.28 Inv. ud 358.13 CB#64 Rim 353.05 Inv. out 346.51 4' deep sump. CB#66A Rim 346.3 Inv. in 340.35 Inv. out 341.6 Use 4' deep sump Rim 339.60 Inv. in 334.85 Inv. out 333.85 (infiltration) Inv. out 335.35 4' deep sump. New CB Rim 363.1 Inv. in 359.4 Inv. out 359.3 New CB Rim 367.2 Inv. out 362.45 Inv. ud 363.2 New CB Rim 364.33 Inv. in 359.58 Inv. out 359.48 Inv. ud 360.33 New CB Rim 362.33 Inv. out 357.58 Inv. ud 358.33 New CB Rim 355.20 Inv. in 350.45 Inv. out 350.35 New CB Rim 361.25 Inv. in 356.5 Inv. out 356.4 New CB Rim 363.1 Inv. out 359.6 New CB Rim 352.1 Inv. in 348.25 Inv. out 348.15 NewDMh Rim 350.0 Inv. in 345.75 Inv. out 345.65 New CB Rim 344.4 Inv. in 339.9 Inv. out 339.8 New CB Rim 352.0 Inv. out 348.0 NewDMh Rim 349.6 Inv. in 343.45 Inv. out 343.35 New 10" PVC Roof Drain. Coordinate with mechanical plans (typical all roof drains) New 10" PVC Roof Drain 2, New 10" PVC Roof Drains New 10" PVC Roof DrainNew 15" HDPE s=0.085New CB Rim 366.25 Inv. in 361.8 Inv. out 361.7 New CB Rim 366.25 Inv. in 362.0 Inv. out 361.9 New 10" PVC Roof Drain Ne w 1 5 " H D P E New 15 " H D P E s=0.07New 15" HDPE s=0.005New 15" HDPEs=0.01New 22 1/2° bend with thrust block. New 45° bends with thrust blocks. New Hydrant assembly New 8" x 6" tee with thrust block. New 8" x 6" reducer HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-3.1 SITE UTILITIES PLAN LOT 13 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 35' x 25' Screened Trash/ Recycling Pad 3, 12' wide swing gates Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-4.1 Proposed 124 Unit Building 5.6' setback Screened Trash/ Recylcing New gas serviceNew Bike Rack New Transformer New Transformer HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-3.2 SITE GRADING PLAN LOT 13 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 35' x 25' Screened Trash/ Recycling Pad 3, 12' wide swing gates Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-4.2 Proposed 124 Unit Building 5.6' setback HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-3 SITE MATERIALS PLAN LOT 13 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 35' x 25' Screened Trash/ Recycling Pad 3, 12' wide swing gates Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-4 Proposed 124 Unit Building 5.6' setback New paved parking New paved parking New paved driveway New paved parkingScored concrete. Refer to Landscape plan. New paved driveway New concrete curb New concrete curb New concrete sidewalk New stairs New concrete sidewalk New concrete entrance New concrete curb 10' con c r e t e w a l k New 5' concrete walkNew 5' concrete walkNew 5' concrete walk Ne w 5 ' c o n c r e t e w a l k New bike rack New bike rack New patio amenity. Refer to landscape plan New ramp New ramp New stairsNew stairs New retaining wall New retaining wall New patio amenity. Refer to landscape plan 15" HDPE s=0.08915" HDPE s=0.052Gravel Wetland #2 Cell#2 121' x 32' Elev. 331.0Gravel Wetland #2 Cell#1 121' x 32' Elev. 331.0 New 15" HDPE s = 0 . 0 1New 18" HDPE s=0.028New 18 " HDPE s=0 .1 2 New 1 8 " H D P E s = 0 . 1 0 7 New 18" HDPE s=0.03 3 New 15" HDPE s=0.01 New 15 " H D P E s=0.01 Ne w 1 5 " H D P E s = 0 . 0 1 New 1 5 " HDPE s = 0 . 0 5 4 New 15" HDPE s=0.052New 15" HDPE s=0 .043 New 1 5 " H D P E s = 0 . 0 2 1 New 12" HDPE s=0.057New 18" H D P E New 18" HDPEs=0.029New 15" HDPE s=0.01 New 12" HDPEs=0.03New 12" HDPE s=0.057New 12" HDPE s=0.097New 15" HDPE s=0.091New Gas meter New 45° bends with thrust blocks. New 6" tapping sleeve and valve.6"4"New 6" D.I. Cl 52 fire and 4" D.I. domestic water service to building. Connect to Phase 1 stub. Coordinate with mechanical plans. New 6"x4" tee with respective gate valves New 6" D.I. Cl 52 fire and 4" D.I. domestic water service to building. Coordinate with mechanical plans. New 6"x4" tee with respective gate valves New 6" PVC SDR 35 sanitary sewer service to building. s=14"/ft min. Connect to Phase 1 stub. Coordiante with mechanical plans. New 6" PVC SDR 35 sanitary sewer service to building. Connect to Phase 1 stub. New emergency spillway New Outlet Structure C. See detail. New End Section Inv. 329.5 New 18" End Section Inv. 332.0 New rip rap dispersal pad New CB Rim 348.25 Inv. in 343.25 Inv. out 343.15 New CB Rim 350.4 Inv. in 345.92 Inv. out 345.82 New CB Rim 352.4 Inv. in 346.9 Inv. out 346.8 New CB Rim 353.70 Inv. in 347.9 Inv. out 347.8 New CB Rim 353.7 Inv. in 348.25 Inv. out 348.15 New CB Rim 353.8 Inv. in 349.05 Inv. out 348.95 New CB Rim 360.4 Inv. in 355.65 Inv. out 355.55 New CB Rim 355.15 Inv. in 349.78 Inv. out 349.68 New CB Rim 356.7 Inv. in 351.95 Inv. out 351.85 CB#66A Rim 346.3 Inv. in 340.35 Inv. out 341.6 Use 4' deep sump CB#66 Rim 339.60 Inv. in 334.85 Inv. out 333.85 (infiltration) Inv. out 335.35 4' deep sump. Inv. out 327.77 Inv. ud 329.10 4' deep sump. Inv. 327.77 New CB Rim 338.9 Inv. in 333.9 Inv. out 333.8 New CB Rim 339.5 Inv. in 334.5 Inv. out 334.4 New CB Rim 355.20 Inv. in 350.45 Inv. out 350.35 Inv. out 347.0 New CB Rim 347.12 Inv. in 337.12 Inv. out 337.02 New CB Rim 344.4 Inv. in 339.9 Inv. out 339.8 Future Gravel Wetland New CB Rim 352.0 Inv. out 348.0 New 10" PVC Roof Drain New End Section Inv. 332.5 New rip rap dispersal pad New 10" PVC Roof Drain New End Section Inv. 332.5 New rip rap dispersal pad New End Section Inv. 332.5 New rip rap dispersal pad New DMh Rim 343.25 Inv. in 336.4 Inv. out 336.3 New 10" PVC Roof Drain New 10" PVC Roof Drain. s=0.01 min. New 15" HDPE s=0.061 NewDMh Rim 349.6 Inv. in 343.45 Inv. out 343.35 New 10" PVC Roof Drain 2, New 10" PVC Roof Drains New 10" PVC Roof DrainNew 15" HDPE s=0.0854" 6" New 22 1/2° bend with thrust block. New 45° bends with thrust blocks. New Hydrant assembly New 8" x 6" tee with thrust block. New 8" x 6" reducer HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-4.1 SITE UTILITIES PLAN LOT 15 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-3.1 Proposed 127 Unit Building HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-4.2 SITE GRADING PLAN LOT 15 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-3.2 Proposed 127 Unit Building HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-4 SITE MATERIALS PLAN LOT 15 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac SEE SHEET C-3 Proposed 127 Unit Building New paved driveway New paved parking Scored concrete. Refer to Landscape plan. New paved driveway New concrete curb New concrete sidewalk New concrete sidewalk New concrete curb New 5' concrete walk New bike rack New ramp New stairs New stairs New retaining wall New patio amenity. Refer to landscape plan New 5' concrete walk New bike rack New 5' p a v e d w a l k New 5' paved walk New retaining wall New patio amenity. Refer to landscape plan New stairs New stairs New concrete sidewalk Crosswalk to trash/recycling New concrete 50' Wetland Setbac k Wetland A T y p e I I I 50' We t land Se tb ac k Wetland B T y p e I I I 50' WetlandSetbackWetland C Type III POST1 A1 A2 A3 ZONE1 PARK FUTURE1 SWMB SWMC SWMA SWMAGC1 GC1 GC3 GCA1 GCA2 GCA3 ZONE1 Existing Lot 1 Area = 8.9 acres "Lancaster" Area = 5.0 acres "Stonington" Existing Lot 2 Existing Lot 3 Open Land Area = 2.0 acresExist ing Pond # 1 Existin g P o n d # 2 Existing P o n d # 3 Note: Lot 12 & 14 permanent improvements are shown for schematic purposes Lot 10 Area = 0.9 ac HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-6 SOILS RESTORATION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Lot 14 Area = 1.1 ac Lot 12 Area = 1.6 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 11 Area = 1.2 ac Gravel Wetland #1 Gravel Wetland #2 Lot 18 Area = 0.56 ac REFER TO SITE NOTES AND LEGEND SHEET C-1 Note: Lot 12 & 14 permanent improvements are shown for schematic purposes · · · · · Post-Construction Soil Depth and Quality Notes Required Elements: Soil retention: Retain, in an undisturbed state, the duff layer and native topsoil to the maximum extent practicable. Soil quality: All areas subject to the Standard shall demonstrate the following: ■A topsoil layer with a minimum organic matter content of 4% dry weight in planting beds and turf areas. The topsoil layer shall have a minimum depth of 4 inches, except where tree roots limit the depth of incorporation of amendments needed to meet the criteria. ■Compost and other materials shall be used that meet the following requirements: o The compost or other materials shall have a carbon to nitrogen ratio below 25:1. o Compost shall meet the definition of “compost” in the Agency's Solid Waste Management Rules or shall meet the contaminant standards in the Vermont Solid Waste Management Rules §6-1104(g)(6- 7), §6-1105(e)(8-9), and §6-1106(e)(7-9). Compost or other organic materials may be amended to meet the foregoing requirements. o Exceptional Quality biosolids (EQ biosolids) may be used as a soil amendment, at a maximum proportion of 35% of the total soil volume, and shall be well mixed with existing soil before or during application. ■The resulting soil shall be conducive to the type of vegetation to be established. ■The soil quality requirements shall be met by using one or a combination of the following methods: o Option 1: Leave undisturbed native vegetation and soil, and protect from compaction during construction. Failure to establish and maintain exclusionary controls around these areas during the construction phase may trigger the requirement to restore soils per one of the following options. o Option 3: Remove and stockpile existing topsoil during grading. ▪Stockpile soil on site in a designated controlled area, at least 50 feet from surface waters, wetlands, floodplains, or other critical resource areas; ▪Scarify or till subgrade to a depth of 4 inches. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ▪Stockpiled topsoil shall also be amended, if needed, to meet the organic content requirements: ·PRE-APPROVED RATE: Compost shall be incorporated with an organic matter content between 40 and 65% into the topsoil at a ratio 1:3, or ·CALCULATED RATE: Incorporate composted material or approved organic material at a calculated rate to achieve 4 inches of settled soil at 4% organic content;* ▪Replace stockpiled topsoil prior to planting, screen topsoil, and; ▪Rake to level, and remove surface rocks larger than 2 inches in diameter. o Option 4: Import topsoil mix, or other materials for mixing, including compost, of sufficient organic content and depth. ·Scarify or till subgrade to a depth of 4 inches. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ·Place 4 inches of imported topsoil mix on surface. The imported topsoil mix shall contain 4% organic matter. Soils used in the mix shall be sand or sandy loam as defined by the USDA; Shop drawing submittal is required. Find USDA sieve for sand and sandy loam. ·Rake beds to smooth and remove surface rocks larger than 2 inches in diameter; and ·Water or roll to compact soil in turf areas to 85% of maximum dry density. Soil Management: o Identifies areas on the site subject to the Standard; o Soil depth and quality shall be established towards the end of construction and once established, protected from compaction, such as from large machinery, vehicle traffic, and from erosion; and o After soil amendments and placement is complete, and prior to seeding and mulching, Contractor shall perform verification sampling in locations indicated on sampling plan. Verification sampling shall include nine, 8 inch deep (min) test holes per acre of area subject to the standard. Test holes shall be excavated using only a shovel driven solely by inspector's weight and shall be at least 50 feet apart from each other. ■A dense and vigorous vegetative cover shall be established over turf areas. o Option 2: Amend existing site topsoil or subsoil in place. ▪Scarify or till subsoils to 4 inches of depth or to depth needed to achieve a total depth of 8 inches of uncompacted soil after calculated amount of amendment is added. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ▪Amend soil to meet organic content requirements: ·PRE-APPROVED RATE: Place 1 inch of composted material with an organic matter content between 40 and 65% and rototill into 3 inches of soil, or ·CALCULATED RATE: Place calculated amount of composted material or approved organic material and rototill into depth of soil needed to achieve 4 inches of settled soil at 4% organic content. *Contractor to provide calculation and site sketch indicating areas used for calculations. ▪Rake beds to smooth and remove surface rocks larger than 2 inches in diameter; and ▪Water or roll to compact soil in turf areas to 85% of maximum dry density. LOTS 13 & 15 Proposed 124 Unit Building Proposed 127 Unit Building Lot 10 Area = 0.9 ac HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-6 SOILS RESTORATION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Lot 14 Area = 1.1 ac Lot 12 Area = 1.6 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 11 Area = 1.2 ac Gravel Wetland #1 Gravel Wetland #2 Lot 18 Area = 0.56 ac REFER TO SITE NOTES AND LEGEND SHEET C-1 Note: Lot 12 & 14 permanent improvements are shown for schematic purposes · · · · · Post-Construction Soil Depth and Quality Notes Required Elements: Soil retention: Retain, in an undisturbed state, the duff layer and native topsoil to the maximum extent practicable. Soil quality: All areas subject to the Standard shall demonstrate the following: ■A topsoil layer with a minimum organic matter content of 4% dry weight in planting beds and turf areas. The topsoil layer shall have a minimum depth of 4 inches, except where tree roots limit the depth of incorporation of amendments needed to meet the criteria. ■Compost and other materials shall be used that meet the following requirements: o The compost or other materials shall have a carbon to nitrogen ratio below 25:1. o Compost shall meet the definition of “compost” in the Agency's Solid Waste Management Rules or shall meet the contaminant standards in the Vermont Solid Waste Management Rules §6-1104(g)(6- 7), §6-1105(e)(8-9), and §6-1106(e)(7-9). Compost or other organic materials may be amended to meet the foregoing requirements. o Exceptional Quality biosolids (EQ biosolids) may be used as a soil amendment, at a maximum proportion of 35% of the total soil volume, and shall be well mixed with existing soil before or during application. ■The resulting soil shall be conducive to the type of vegetation to be established. ■The soil quality requirements shall be met by using one or a combination of the following methods: o Option 1: Leave undisturbed native vegetation and soil, and protect from compaction during construction. Failure to establish and maintain exclusionary controls around these areas during the construction phase may trigger the requirement to restore soils per one of the following options. o Option 3: Remove and stockpile existing topsoil during grading. ▪Stockpile soil on site in a designated controlled area, at least 50 feet from surface waters, wetlands, floodplains, or other critical resource areas; ▪Scarify or till subgrade to a depth of 4 inches. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ▪Stockpiled topsoil shall also be amended, if needed, to meet the organic content requirements: ·PRE-APPROVED RATE: Compost shall be incorporated with an organic matter content between 40 and 65% into the topsoil at a ratio 1:3, or ·CALCULATED RATE: Incorporate composted material or approved organic material at a calculated rate to achieve 4 inches of settled soil at 4% organic content;* ▪Replace stockpiled topsoil prior to planting, screen topsoil, and; ▪Rake to level, and remove surface rocks larger than 2 inches in diameter. o Option 4: Import topsoil mix, or other materials for mixing, including compost, of sufficient organic content and depth. ·Scarify or till subgrade to a depth of 4 inches. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ·Place 4 inches of imported topsoil mix on surface. The imported topsoil mix shall contain 4% organic matter. Soils used in the mix shall be sand or sandy loam as defined by the USDA; Shop drawing submittal is required. Find USDA sieve for sand and sandy loam. ·Rake beds to smooth and remove surface rocks larger than 2 inches in diameter; and ·Water or roll to compact soil in turf areas to 85% of maximum dry density. Soil Management: o Identifies areas on the site subject to the Standard; o Soil depth and quality shall be established towards the end of construction and once established, protected from compaction, such as from large machinery, vehicle traffic, and from erosion; and o After soil amendments and placement is complete, and prior to seeding and mulching, Contractor shall perform verification sampling in locations indicated on sampling plan. Verification sampling shall include nine, 8 inch deep (min) test holes per acre of area subject to the standard. Test holes shall be excavated using only a shovel driven solely by inspector's weight and shall be at least 50 feet apart from each other. ■A dense and vigorous vegetative cover shall be established over turf areas. o Option 2: Amend existing site topsoil or subsoil in place. ▪Scarify or till subsoils to 4 inches of depth or to depth needed to achieve a total depth of 8 inches of uncompacted soil after calculated amount of amendment is added. Except for within the drip line of existing trees, the entire surface shall be disturbed by scarification; ▪Amend soil to meet organic content requirements: ·PRE-APPROVED RATE: Place 1 inch of composted material with an organic matter content between 40 and 65% and rototill into 3 inches of soil, or ·CALCULATED RATE: Place calculated amount of composted material or approved organic material and rototill into depth of soil needed to achieve 4 inches of settled soil at 4% organic content. *Contractor to provide calculation and site sketch indicating areas used for calculations. ▪Rake beds to smooth and remove surface rocks larger than 2 inches in diameter; and ▪Water or roll to compact soil in turf areas to 85% of maximum dry density. LOTS 13 & 15 Proposed 124 Unit Building Proposed 127 Unit Building HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-7A EXISTING CONDITIONS PLAN LOT 17 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOT 17 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Gravel Wetland #2 Cell#2 121' x 32' Elev. 331.0 New 1 5 " H D P E s = 0 . 0 2 1 New 1 5 " H D P E s = 0. 0 8 6New 1 5" HDPE s = 0 .0 3 9 New 12" HDPE s=0.06New 12" HDPE s=0.0 1 New 15" HDPE s= 0 . 0 1 New 15 " H D P E s=0.01 Ne w 1 5 " H D P E s = 0 . 0 1 New 1 5 " HDP E s= 0 . 0 5 4 New 15" HDPE s=0.02New 15" HDPE s=0.052New 15" HDPE s=0 .043 New 1 5 " H D P E s = 0 . 0 2 1 New 12" HDPE s=0.057New 15"HDPE s=0.01New 15"HDPE s=0.01New 12" HDPE s = 0 . 0 0 5 New 15" HDPE s=0.01 New 15 " H D P E s = 0. 0 4 3 Ne w 1 2 " H D P E s = 0 . 0 3 New 12" HDPE New g a s s e r v i c e New gas serviceNew 12" HDPEs=0.03New Transformer New Transformer New Gas meter New Gas meter New paved walk New gate valve, cap, stub, thrust block, and witness for 8" water main. New Hydrant assembly New 8" x 8" x 8" tee, thrust block and gate valve. New 8" water stub with cap, trhust block and witness New Hydrant assembly New CB Rim 352.4 Inv. in 346.9 Inv. out 346.8 New CB Rim 353.70 Inv. in 347.9 Inv. out 347.8 New CB Rim 353.7 Inv. in 348.25 Inv. out 348.15 New CB Rim 353.8 Inv. in 349.05 Inv. out 348.95 New CB Rim 360.4 Inv. in 355.65 Inv. out 355.55 New CB Rim 363.05 Inv. in 358.3 Inv. out 358.2 New CB Rim 364.5 Inv. out 360.0 New CB Rim 355.15 Inv. in 349.78 Inv. out 349.68 New CB Rim 359.8 Inv. in 354.48 Inv. out 354.38 New CB Rim 364.6 Inv. in 358.84 Inv. out 358.74 New CB Rim 359.55 Inv. out 355.05 New CB Rim 356.7 Inv. in 351.95 Inv. out 351.85 New CB Rim 359.55 Inv. out 355.05 New CB Rim 365.75 Inv. out 361.25 New CB Rim 372.8 Inv. in 367.91 Inv. out 367.81 Inv. ud 368.66 New CB Rim 372.9 Inv. out 368.15 Inv. ud 368.9 New CB Rim 370.9 Inv. in 366.15 Inv. out 366.05 Inv. ud 366.9 New CB Rim 370.9 Inv. in 365.9 Inv. out 365.8 Inv. ud 366.65 New CB Rim 363.1 Inv. in 359.4 Inv. out 359.3 New CB Rim 355.20 Inv. in 350.45 Inv. out 350.35 New CB Rim 361.25 Inv. in 356.5 Inv. out 356.4 New CB Rim 363.1 Inv. out 359.6 Inv. out 347.0 Future Gravel Wetland New CB Rim 352.0 Inv. out 348.0 New 10" PVC Roof Drain New End Section Inv. 332.5 New rip rap dispersal pad New End Section Inv. 332.5 New rip rap dispersal pad New DMh Rim 343.25 Inv. in 336.4 Inv. out 336.3 New 10" PVC Roof Drain New 10" PVC Roof Drain. s=0.01 min. New 15" HDPE s=0.061 New 10" PVC Roof Drain. Coordinate with mechanical plans (typical all roof drains) New CB Rim 371.0 Inv. in 366.25 Inv. out 366.15 Ne w 1 5 " H D P E s= 0 . 0 2 1 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: C-7 SITE PLAN LOT 17 Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOT 17 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac NOTE: Lots 13 and 15 will have the right to utilize the parking and utilities shown on Lot 17. Exact locations of the necessary easements will be determined upon completion of a development plan for the remainder of Lot 17. HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-1 CIVIL DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 SPECIFICATIONS: Plan Section 1" x 45° Chamfer Conduit Anchor Bolts Conduit, typ. Anchor Bolts PVC PVC 24" 5 ft. min. NOTE: See Electrical Plans for electrical, conduit, and grounding design. - Concrete Minimum Strength 5000psi @ 28 days - Reinforcement per Specification. Reinforcing shall be ASTM A615 Grade 60 - PVC Conduit Supplied by Others - Anchor Bolts Supplied by Others - Weights Subject to Variation (4) #4 Vertical rebar #4 rebar @ 12" o.c. horizontal 3" reveal. Verify with SBDPW.Finished grade Coordinate bolt configuration with light pole Maintain 3" clear (min.) for rebar from top, bottom, and sides Maintain 3" clear for rebar Weep hole for grounding conductor. 24" No. 6 soft drawn copper grounding conductor. Connect to grounding lug in pole. Weep hole. Install 1/2" flexible plastic conduit for #6 AWG soft copper grounding conductor. Connect to grounding electrode using an exothermic weld. 3/4" X 10' minimum copper clad grounding electrode Top of grounding electrode 12" minimum below ground level HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-2 CIVIL DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-3 CIVIL & WATER DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com CHAMPLAIN WATER DISTRICT SOUTH BURLINGTON, VT 05403403 QUEEN CITY PARK ROAD DRAWING NO.: DATE: TAPPING SLEEVE & VALVE DETAIL Specifications Detail CHAMPLAIN WATER DISTRICT A-5 A-5 Tapping Sleeve and Valve.dwg JUNE 2019 403 QUEEN CITY PARK ROADSOUTH BURLINGTON, VT 05403 CHAMPLAIN WATER DISTRICT Minimum Area In Square Feet, Of Bearing Surface Required For Concrete Thrust Blocks 403 QUEEN CITY PARK ROADSOUTH BURLINGTON, VT 05403 CHAMPLAIN WATER DISTRICT NOT TO SCALE θ NOT TO SCALE CHAMPLAIN WATER DISTRICT SOUTH BURLINGTON, VT 05403403 QUEEN CITY PARK ROAD DRAWING NO.: DATE: BEARING BLOCK Specifications Detail CHAMPLAIN WATER DISTRICT A-27 A-27 Bearing Block.dwg April 2019 LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-4 CIVIL & WATER DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com NOT TO SCALE TYPICAL TRENCH DETAIL CHAMPLAIN WATER DISTRICT SOUTH BURLINGTON, VT 05403403 QUEEN CITY PARK ROAD DRAWING NO.: DATE: TYPICAL TRENCH DETAIL Specifications Detail CHAMPLAIN WATER DISTRICT A-1 A-1 Typical Trench.dwg April 2019 HYDRANT ASSEMBLY NOT TO SCALE CHAMPLAIN WATER DISTRICT SOUTH BURLINGTON, VT 05403403 QUEEN CITY PARK ROAD DRAWING NO.: DATE: HYDRANT ASSEMBLY Specifications Detail CHAMPLAIN WATER DISTRICT A-16 A-16 Hydrant Assembly.dwg JUNE 2019 LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-5 CIVIL & WATER DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com · · · · · · ·√ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·¾ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-6 CIVIL & SANITARY DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 A A B B HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-7 CIVIL & STORM DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-8 EROSION PREVENTION & SEDIMENT CONTROL DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com 3B. 1. 6. 7. 2. 5. 4.8. 3. 1. 3A. LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-9 EROSION PREVENTION & SEDIMENT CONTROL DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com “” “” “” “” “” “” “” “” “” “” “” “” ’ ’ · · · · LOTS 13 & 15 NOTE: Details on this sheet provided by Green Mountain Power. HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: D-10 SITE ELECTRIC DETAILS Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-1 PRE-CONSTRUCTION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 LOTS 13 & 15 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com REFER TO SITE NOTES AND LEGEND SHEET C-1 Lot 10 Area = 0.9 ac Lot 14 Area = 1.1 ac Lot 12 Area = 1.6 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 11 Area = 1.2 ac SEE SHEET EPSC-2 HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-2 PRE-CONSTRUCTION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 LOTS 13-15 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Lot 17 Area = 4.3 ac Lot 18 Area = 0.56 ac REFER TO SITE NOTES AND LEGEND SHEET C-1SEE SHEET EPSC-1SEE SHEET EPSC-3 Screened Trash/ Recylcing New gas serviceNew Bike Rack New Transformer New Transformer HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-3 EPSC CONSTRUCTION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 35' x 25' Screened Trash/ Recycling Pad 3, 12' wide swing gates Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac CONSTRUCTION NOTES SEE SHEET EPSC-5SEE SHEET EPSC-4 Proposed 124 Unit Building New gas serviceNew Transformer New paved walk New Bike Rack HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-4 EPSC CONSTRUCTION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com LOTS 13 & 15 Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac CONSTRUCTION NOTES SEE SHEET EPSC-5SEE SHEET EPSC-3 Proposed 127 Unit Building New gas serviceNew Gas meter New paved walk HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-5 EPSC CONSTRUCTION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 LOTS 13 & 15 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com SEE SHEET EPSC-4REFER TO SITE NOTES AND LEGEND SHEET C-1 CONSTRUCTION NOTES SEE SHEET EPSC-3Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac 10' paved pathLot 10 Area = 0.9 ac HILLSIDE @ O'BRIEN FARM OWNER AND APPLICANT: ISSUED FOR PERMIT REVIEW NOT FOR CONSTRUCTION PROPERTY INFORMATION: EPSC-6 EPSC STABILIZATION PLAN Old Farm Road and Kennedy Drive, South Burlington, Vermont O'BRIEN BROTHERS 1855 WILLISTON ROAD SOUTH BURLINGTON, VT 05403 164 Main Street, Suite 201 P: (802) 878-0375 Colchester, Vermont 05446 email@krebsandlansing.com Lot 14 Area = 1.1 ac Lot 12 Area = 1.6 ac Lot 13 Area = 2.1 ac Lot 15 Area = 2.3 ac Lot 17 Area = 4.3 ac Lot 11 Area = 1.2 ac Gravel Wetland #1 Gravel Wetland #2 8 Spaces11' con c r e t e s i d e w a l k10' concrete sidewalk5' concrete sidewalk 5' concrete sidewalk5' concrete sidewalk Lot 18 Area = 0.56 ac STABILIZATION NOTES: REFER TO SITE NOTES AND LEGEND SHEET C-1 Note: Lot 12 & 14 permanent improvements are shown for schematic purposes Proposed 124 Unit Building Proposed 127 Unit Building Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook The name above will appear on all the discharge point tabs Site Summary Total SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 New 7.46 0.00 0.00 0.00 7.46 0.00 0.00 0.00 0.00 0.00 Redeveloped 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Existing 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Previously Authorized 6.22 0.00 0.00 0.00 6.22 0.00 0.00 0.00 0.00 0.00 Total 13.68 0.00 0.00 0.00 13.68 0.00 0.00 0.00 0.00 0.00 Site Area 19.20 0.00 0.00 0.00 19.20 0.00 0.00 0.00 0.00 0.00 0.00000 0.00000 0.00000 44.46039 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 ‐73.07617 0.00000 0.00000 0.00000 0.00000 0.00000 Receiving Water Potash Brook Recharge Total SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 Required 0.2953 0.0000 0.0000 0.0000 0.2953 0.0000 0.0000 0.0000 0.0000 0.0000 Provided 1.4440 0.0000 0.0000 0.0000 1.4440 0.0000 0.0000 0.0000 0.0000 0.0000 Standard met?Yes n/a n/a n/a Yes n/a n/a n/a n/a n/a Notes: Water Quality Total SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 Required 0.6136 0.0000 0.0000 0.0000 0.6136 0.0000 0.0000 0.0000 0.0000 0.0000 Provided 1.9057 0.0000 0.0000 0.0000 1.9057 0.0000 0.0000 0.0000 0.0000 0.0000 Standard met?Yes n/a n/a n/a Yes n/a n/a n/a n/a n/a Notes: Channel ProtectionImperviousProject Name Do not fill this tab out, apart from the project name and notes. It will auto‐populated based on the values on the discharge point tabs. Discharge points (SN) will only show on the summary if an area has been entered on that tab. Areas listed below are those seeking permit coverage. Hillside @ O'Brien Farm Latitude Longitude A minimum WQ V of 0.2" (P*R V ) is required for sites with low impervious (<16.67%). This calculation has not been incorporated into this workbook. Designers should check that the minimum WQ V has been met for their site. Last Updated 8/28/2018 Summary: Page 3 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook Total SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 Standard Applies?000Yes 00000 Waiver n/a Method n/a n/a n/a Hydrologic Condition Method n/a n/a n/a n/a n/a HCV 1.0375 0.0000 0.0000 0.0000 1.0375 0.0000 0.0000 0.0000 0.0000 0.0000 TV Provided 1.4440 0.0000 0.0000 0.0000 1.4440 0.0000 0.0000 0.0000 0.0000 0.0000 Notes: Overbank Flood Protection SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 Standard Applies?000Yes 00000 Pre‐Dev Q (cfs) 3.46 Routed, Post‐Dev Q (cfs) 1.23 Waiver n/a Notes: Extreme Flood Protection SN1 SN2 SN3 SN4 SN5 SN6 SN7 SN8 SN9 Standard Applies?Yes Pre‐Dev Q (cfs) 18.09 Routed, Post‐Dev Q (cfs) 14.54 Waiver n/a Notes: General Notes Last Updated 8/28/2018 Summary: Page 4 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook Last Updated 8/28/2018 Summary: Page 5 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook General Discharge Point Information Project name Discharge point serial number (e.g. S/N 001) Name of receiving water Latitude (decimal degrees to five decimal places) Longitude (decimal degrees to five decimal places) Precipitation Data NOAA Atlas 14 Storm WQ Storm 1 yr, 24 hr 10 yr, 24 hr 100 yr, 24 hr Precipitation (inches) 1.00 1.90 3.25 4.85 Drainage Area Information Landuse A B C D Total Grass 0.190 0.190 3.300 0.000 3.680 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 4.500 4.500 0.300 0.000 9.300 Existing Impervious 0.000 0.000 0.000 0.000 0.000 Impervious previously authorized under 2002 VSMM (not included in calculations)6.220 Total Pre Site Area 19.200 % Landuse A B C D Total Grass 1.110 1.110 3.300 0.000 5.520 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 0.000 0.000 0.000 0.000 0.000 New Impervious 3.730 3.730 0.000 0.000 7.460 57.5% Existing for Permit Coverage (Treated to New Standards) 0.000 0.000 0.000 0.000 0.000 0.0% Existing Impervious Not for Permit Coverage 0.000 0.0% Redeveloped Impervious 0.000 0.0% 6.220 Total Site Area 19.200 Total Impervious for Permit Coverage 13.680 Net Reduced Impervious 0.000 0.0% Reduced Existing Impervious (for redevelopment)0.000 0.0% Average Catchment Slope, Y (%) Hydraulic Length, l (ft) Pre Development 9.1 1275.00 Post Development 9.1 1275.00 Information for Calculating TC by the Watershed Lag Method Hillside @ O'Brien Farm 4 Potash Brook 44.46039 ‐73.07617 * Preciptation values shall be obtained from Pre Development Land Use (acres) Post Development Land Use (acres) Impervious previously authorized under 2002 VSMM Last Updated 8/28/2018 SN4: Page 6 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook Runoff Calculations 1 yr, 24‐hr 10 yr, 24‐hr 100 yr, 24‐hr 0.0927 0.4243 1.0375 1.1302 2.2215 3.6694 Tier 1/Runoff Reduction Practices Practice TV (ac‐ft) TV (ac‐ft) Infiltration Basin 1.444 Runoff Reduction Calculations Standard Re WQ CP QP10 QP100 TV Required (ac‐ft)0.2953 0.6136 1.0375 1.7972 2.6320 TV Provided (ac‐ft)1.4440 1.4440 1.4440 1.4440 1.4440 TV Remaining (ac‐ft)0.0000 0.0000 0.0000 0.3532 1.1880 Standard met with HCM?Yes Yes Yes No No Post‐Development CN n/a 95 91 88 87 CNadj n/a n/a n/a 67 72 Pre‐Development CN n/a n/a 63 59 56 Groundwater Recharge Standard (Re)1 Standard Applicable? ReV 0.2953 Standard met with Tier 1 Practices? Yes Recharge Notes: Recharge is met via existing Infiltration Basin A Predevelopment runoff volume (ac‐ft) Pre‐routed, post development runoff volume (ac‐ft) List all Tier 1 practices below with the associated treatment volume (TV ). The T V will be applied to all treatment standards, except for Green Roofs, which do not receive recharge or water quality credit. Please include the appropriate STP worksheet(s) with the application. Practice Yes No Last Updated 8/28/2018 SN4: Page 7 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook Water Quality Treatment Standard (WQ)11 (ac‐ft) Apply Reduction? WQV ‐ New & Existing 0.6136 0.0% WQV ‐ Redevelopment 0.0000 0.0% Total WQV 0.6136 WQV met with Tier 1 practices 0.6136 1 WQV to be met with Tier 2 and/or Tier 3 practices 0.0000 WQV Provided (ac‐ft)Tier 0.1068 Tier 2 0.3549 Tier 2 Total WQV Provided (ac‐ft)0.4617 ac‐ft Is the WQV Standard met?Yes Water Quality Notes: Channel Protection Standard (CP)21 Standard Applicable? Standard Met with HCM?Yes Provide Extended Detention for:n/a ac‐ft Warm or Cold Water Fishery?→Provide: FALSE Extended Detention STP: CNAdj n/a 7.2 (Watershed Lag Method) Channel Protection Notes: The channel protection standard has been fully met with hydrologic condition method. Additional treatment of the 1 year storm is not required. 24 hours of extended detention See the Vermont Water Quality Standards for warm and cold water designations OR The Alternative Extended Detention Method (§2.2.5.4) is being used. Gravel Wetlands #1 and #2 Modeling Info: When demonstrating CP compliance with extended detention in a hydrologic model, use the CN and TC below if the practice being modelled is not a Tier 1 practice. The CN Adj takes into account the reduction in runoff volume achieved through Tier 1 practices. The T C is calculated by the watershed lag method using CNAdj as CN'. Post Development TC (min) Gravel Wetlands #1 and #2 provide minimum 1" orifices for stormwater draining to each practice. % Net Reduction % Removed Existing Impervious (Redevelopment) Is all impervious treated by disconnection? NOTE: Please include a copy of the appropriate STP worksheet(s) with the application. Tier 2 & 3 Water Quality Practice Gravel Wetland Gravel Wetland Yes No Cold Warm No Yes (WQv met) No Yes No Yes Last Updated 8/28/2018 SN4: Page 8 of 9 Vermont Operational Stormwater Permit ‐ Standards Compliance Workbook Overbank Flood Protection (QP10)1 Standard Applicable? Standard Met with HCM?No STP used: Pre‐development peak discharge rate (cfs) 3.46 Pre‐routed, post‐development peak discharge rate (cfs) Routed, post‐development peak discharge rate (cfs) 1.23 Pre‐Development CN (Flow‐ weighted composite)59 22.7 CNAdj 67 18.4 Overbank Flood Notes: Extreme Flood Protection (QP100)1 Standard Applicable? Standard Met with HCM?No STP used: Pre‐development peak discharge rate (cfs) 18.09 Pre‐routed, post‐development peak discharge rate (cfs) Routed, post‐development peak discharge rate (cfs) 14.54 Pre‐Development CN (Flow‐ weighted composite)56 24.6 CNAdj 72 16.3 Extreme Flood Notes: Pre Development TC (min)(Watershed Lag Method)Post Development TC (min) The extreme standard has not been fully met. Provide additional STPs to ensure post development peak runoff does not exceed pre development peak runoff for the 100 yr, 24 hour storm event. Wet Pond, Infiltration Basin, Gravel Wetlands Modeling Info: When demonstrating Q P100 compliance in a hydrologic model, use the following CN and T C below, if the practice used to meet QP100 is not a Tier 1 practice. The CN Adj takes into account the reduction in runoff volume achieved through runoff reduction practices. The T C is calculated by the watershed lag method using CN Adj as CN'. The QP10 standard has not been fully met. Provide additional STPs to ensure post development peak runoff does not exceed pre development peak runoff for the 10 yr, 24 hour storm event. Wet Pond, Infiltration Basin, Gravel Wetlands Modeling Info: When demonstrating Q P10 compliance in a hydrologic model, use the following CN and T C below, if the practice used to meet QP10 is not itself a Tier 1 practice. The CN Adj takes into account the reduction in runoff volume achieved through Tier 1 practices. The T C is calculated by the watershed lag method using CNAdj as CN'. Pre Development TC (min)(Watershed Lag Method)Post Development TC (min) Yes No Yes No Last Updated 8/28/2018 SN4: Page 9 of 9 STP Selection Matrix Project Name: Version 5/8/2017 Discharge Point: Step 1: Is the Water Quality Treatment Standard entirely managed with one or more of the following Tier 1 practices? Infiltration Basins/ Trenches/ Chambers Simple Disconnection Drywells Disconnection to Filter Strips and Vegetated Buffers Bioretention (designed to infiltrate) Dry Swales (designed to infiltrate) Filters (designed to infiltrate)Permeable Pavement1 Reforestation1 2 1. These practices do not require specific justification due to feasibility limitations Step 2: Assess the feasibility of using Tier 1 Practices Infiltration Basin/ Trench/ ChamberDrywellBioretention (infiltrating)Simple DisconnectionDisconnection to Filter Strips or Vegetated BufferDry Swales (infiltrating)Filters (infiltrating)Practice Availability for Water Quality Treatment?Not Feasible Not Feasible Yes Yes Yes Yes Yes Response Available Available Available n/a n/a Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available Available n/a n/a n/a Available Available n/a n/a n/a n/a n/a Available n/a n/a n/a n/a n/a n/a n/a Available n/a n/a Available n/a Available n/a n/a Available Available Available Available Available n/a n/a Available Available Not Feasible Not Feasible n/a n/a n/a n/a n/a Not Feasible n/a n/a n/a n/a n/a n/a Tier 1 Practices are available to meet the Water Quality Treatment Standard. If using one of these practices, stop here. If additional site constraints exist other than those listed here, proceed to Step 3. Hillside @ O'Brien Farm S/N 004 Complete the matrix below in its entirety for each drainage area. Proceed to Step 2 Seasonal high water table or bedrock would be less than 3 feet from the bottom of the practice. Is the slope of the filter strip greater than 15% Is the slope of the vegetated buffer greater than 8% Are natural slopes where an infiltration trench or basin could be sited greater than 15% Bottom of practice would be below seasonal high water table Seasonal high water table or bedrock would be less than 1 foot from the bottom of the practice. Practice Availability Based on RestrictionsFeasibility Restriction Do underlying soils have an infiltration rate of less than 0.2 inches per hour, as confirmed by field geotechnical tests or are classified as Hydrologic Soil Group D according to the NRCS Soil survey? Will runoff to the practice include discharge from a hotspot landuse or activity? Is the site a brownfield or contaminated site where infiltration is restricted or where infiltration would increase the threat of pollution migration, as confirmed in writing by the Department’s Waste Management and Prevention Division? Is the slope of the vegetated buffer greater than 15% Yes No Yes No Yes No Yes No Yes No Yes Yes No No Yes No No Yes No Yes No Yes STP Selection Matrix ‐ SN1 Page 1 of 2 Available Available Available n/a n/a Available Available Available Available Available n/a n/a Available Available Available Available Available n/a n/a Available Available Available Available Available n/a n/a Available Available Available Available Available n/a n/a Available Available Available Available Available Available Available Available Available Step 3: Other feasibility constraints for remaining Tier 1 and Tier 2 practices 1 Provide written feasibilty justification below or list attachments Will the practice be located within 200 feet of non‐ transient non‐community groundwater source? Will the practice be located within 75 feet down‐ gradient of a wastewater disposal area system, within 35 feet up‐gradient or 75 feet down‐ gradient of a wastewater disposal system? Will the practice be located within 150 feet of a drinking water source located in an unconfined aquifer? Will the practice be located within 100 feet of a drinking water source located in bedrock or a confined unconsolidated aquifer? Will the practice be located within Zone 1 or Zone 2 of a public community groundwater source protection area? Stop. No further justification is needed. If the the use of a Tier 1 or Tier 2 Practice is infeasible for reasons beyond those listed in Step 2 of the STP Selection Matrix, a designer may submit site specific detailed feasibility justification that such practices are not feasible following the guidance in Section 2.2.4.1 of the 2017 VSMM. Only after completion of the STP Selection Matrix and determination that Tier and Tier 2 Practices are infeasible shall a designer consider Tier 3 Practices or existing stormwater infrastructure for meeting the Water Quality Treatment Standard (WQTS) on the project site. Is the Water Quality Treatment Standard entirely managed with Tier 2 Practices? If, following completion of Step 2 of the STP Selection Tool there are no Tier 1 Practices available for use on the project site, designers shall consider the use of Tier 2 practices for treatment of the Water Quality Treatment Standard. Will the practice violate any restrictions of the Vermont Wastewater and Potable Water Supply Rules, or their replacement? Yes Yes Yes No Yes No Yes No Yes Yes No No No No STP Selection Matrix ‐ SN1 Page 2 of 2 Attachment 1: Narrative, Location Map, and Soils Map Hillside @ O'Brien Farm Lots 11-15 1. Introduction Krebs and Lansing Consulting Engineers Inc. (K&L) are writing on behalf of O’Brien Brothers to apply for a State Stormwater Discharge Permit pursuant to General Permit 3- 9050 for the next phase of the Hillside @ O’Brien Farm project located on Kennedy Drive, O’Brien Farm Road, and Two Brother. 2. Project Description The next phase of the Hillside @ O’Brien Farm project involves the construction of six multi-family apartment buildings on Lots 11-15. The first phase of development will be buildings on Lots 10 and 11. We expect buildings on Lots 13 and 15 to be permitted and constructed shortly after. Future buildings on Lots 12 and 14 are included as part of this application. As part of this project, O’Brien Farm Road will also be extended towards Old Farm Road. A portion of the proposed parking for Lots 13 and 15 will extend onto Lot 17. Each building features underground parking. The proposed stormwater treatment practices include existing Wet Pond A and Infiltration Basin A, two new Gravel Wetlands, and four infiltration trenches that were previously permitted but not constructed. Forebays are provided for pre-treatment of non-rooftop runoff for each Gravel Wetland. 3. Existing Condition Lots 11-15 of the project were previously permitted as lots for future development. Portions of O’Brien Farm Road, Two Brothers Drive, and associated utilities have been either already constructed, or are currently under construction. Existing soil types on this portion of the site are Adams-Windsor loamy sands. These soils are classified as type A by the U.S. Soil Conservation Service, which normally indicates a low degree of runoff and high infiltrative capacity. However, on-site soil testing, as well as observation during construction, indicates a high seasonal groundwater table at less than three feet below existing ground surface throughout the site. The site slopes from east to west, at times steeply. The pre development condition was divided into five watersheds corresponding with the natural stormwater discharge points of the property. Study point 1 is located at the intersection of Kennedy Drive and Kimball Avenue and drains to S/N005; Study point 2 is a culvert crossing under Kennedy Drive north of Windridge Condominiums, draining Wetland E and eventually to S/N 004; Study point 3 is a culvert crossing under Kennedy Drive south of Windridge draining to S/N001; Study point 4 is the where Wetland A exits the property, Hillside @ O’Brien Farm – Lots 11-15 Stormwater Narrative 2 near Wellsley Grove Condos draining to S/N 002; and Study point 5 is the southwest corner of the property in a swale along Hinesburg Road and drains to S/N003. The proposed development areas and associated stormwater treatment practices all drain to S/N 004. We have redone pre-development stormwater modeling for this watershed. To account for the high seasonal water table, we have calculated half the area as “A” soil and the other half as “B” soil. We believe this better simulates existing conditions on the site due to high water table. Our site visits during construction have indicated there is far more existing runoff from the site than is typically associated with a site that is all “A” soils. 4. Existing Stormwater System The original Eldredge Street development received State of Vermont Stormwater discharge Stormwater Permit #7815-INDS was obtained in September 2017 for Phase 1 of the Hillside development. This permit also incorporated previously permitted infrastructure from Stormwater discharge Permit #1-1520. Existing permitted stormwater infrastructure includes Extended Detention Ponds 1, 2, and 3, Wet Ponds A and B, Infiltration Basin A, six grass channels, and four infiltration trenches. Wet Pond B and the infiltration trenches have not been constructed at this time. 5. Proposed Stormwater System: The proposed stormwater collection, treatment, and detention system will utilize a combination of existing and new stormwater treatment practices (STPs). The watershed draining to SN 004 features the majority of Two Brothers Drive and the majority of O’Brien Farm Road. The proposed buildings on Lots 10 and 11 will drain to the existing/permitted collection system on O’Brien Farm Road and discharge to Wet Pond A/Infiltration Basin A. A portion of the paved parking on Lot 12 will also discharge to Wet Pond A/Infiltration Basin A via a previously installed storm pipe. Because Infiltration Basin A is a “Tier 1 practice”, no modifications are necessary to bring it into compliance with the 2017 State of Vermont Stormwater Manual. The rest of Lot 12, including the building, and Lot 14 will drain to Gravel Wetland #1. Gravel Wetland #1 replaces previously permitted (but not constructed) Wet Pond B. This brings the project into compliance with the 2017 Stormwater Manual. Lots 13 and 15, and the extended portion of O’Brien Farm Road drain to Gravel Wetland #2. We previously showed and modeled Wet Pond C in this location, but it was neither permitted nor constructed. a) Description of Impervious Area: The existing permitted area of impervious surface is 16.24 acres. An additional 6.6 acres of impervious surface is proposed as part of this application. This includes allowances for future buildings and impervious areas on adjacent lots that will likely drain to the treatment practices. All of this is new impervious surface. The new impervious surface is from building roofs, paved roads, driveways, and parking, and concrete sidewalks and pads. The areas are further summarized below: (1) 1.81 additional acres of impervious surface will drain to Wet Pond A/Infiltration Basin. A. This area was previously accounted for in the Hillside @ O’Brien Farm – Lots 11-15 Stormwater Narrative 3 modeling, so no changes were made to the model. (2) An additional 0.45 acres of impervious surface will drain to Gravel Wetland #1. This is in addition to the previous 0.86 acres of impervious surface that was previously permitted to drain to Wet Pond B. (3) 4.34 acres of impervious surface will drain to Gravel Wetland #2. b) Receiving Body: S/N004: Wetlands in Potash Brook watershed c) Fish Habitat Designation for Receiving Water: Warm d) Description of compliance with each of the treatment standards in the 2017 VSMM including the treatment practices or waivers used to meet each of the following standards: i) Post-Construction Soil Depth and Quality Standard: This standard will be met via two options outlined in the VSMM. Option 1: Areas outside of construction will be left undisturbed and protected from compaction during construction. This option will apply only to the far westerly portion of the site. Option 3: Remove and stockpile existing topsoil during construction. On site soil testing indicates and existing sandy loam topsoil layer on the site ranging from 7-13 inches in depth. Given that much of the finish site will be covered in building or paving, there will be an excess of existing topsoil to re store other disturbed areas such as setbacks, vegetated islands, swales, and side-slopes. Compost will be incorporated into the existing topsoil stockpile if needed to achieve 4% organic content. ii) Groundwater Recharge Standard: The Groundwater Recharge standard is met site wide by the use Infiltration Basin A. The standard is met for the Potash Brook watershed. iii) Water Quality Treatment Standard (WQV): S/N004: WQv will be met for S/N 004 via the use of Wet Pond A, Infiltration Basin A, and Gravel Wetlands #1 & #2. The stone voids in the gravel wetland will store 50% of the WQv draining to each wetland. The remaining 50% WQv is provided by extended detention using small diameter orifices to release the remaining WQv over a 24 hour period. Pre-treatment is provided forebays. iv) Channel Protection Standard (CPV): S/N004: The Cpv standard is met by the use of Wet Pond A, Infiltration Basin A, and Gravel Wetlands #1 and #2. Infiltration Basin A will completely infiltrate the 1 year, 24 hour storm. The gravel wetlands will feature outlet structures using low flow orifices to provide the required detention times. Hillside @ O’Brien Farm – Lots 11-15 Stormwater Narrative 4 v) Overbank Flood Protection Standard (QP10): S/N004: The Overbank Flood Protection Standard is met by the use of Wet Pond A, Infiltration Basin A, and Gravel Wetlands #1 and 2. Infiltration Basin A will completely infiltrate the 10 year, 24 hour storm. The gravel wetlands use controlled outlet devices to limit post development peak flows to below pre development levels for the 10 year, 24 hour storm event. vi) Extreme Flood Protection Standard (QP100): S/N004: The Extreme Flood Protection Standard is met by the use of Wet Pond A, Infiltration Basin A, and Gravel Wetlands #1 and 2. The gravel wetlands and infiltration basin use controlled outlet devices to limit post development peak flows to below pre development levels for the 100 year, 24 hour storm event. The following items are attached for review: • Complete NOI form • Attachment 1: Narrative: Narrative, Location Map, and Soils Map. • Attachment 2: Workbooks: STP Selection Tool and Standards Compliance Workbook • Attachment 3: Worksheets: STP and waiver worksheets, grouped by discharge point • Attachment 4: Modeling: Runoff modeling and calculations demonstrating compliance with the applicable treatment standards. • Attachment 5: Plans: Pertinent plan sheets with all required information outlined in Part 7 of the Application Requirements for Operational Permit Document. • A check in the amount of $5916.00 Payable to “State of Vermont”. Hillside @ O’Brien Farm – Lots 11-15 Stormwater Narrative 5 Location Map [Insert project specific location map here. You may download topographic map from the Natural Resource Atlas. Please show the site outline, the location of the discharge point(s) and receiving waters. The scale of the location map should be between 1:20,000 and 1:40,000.] See Attached Location Map. Potash Brook KENNEDY D R I V E OLD FARM ROADK IM B A L L A V E N U EPotash BrookHINE SBURG ROAD INTERST A T E 8 9 X X XStudy Point 2 X SN004 SITE DATE: 9/10/21 LOCATION MAP SCALE: 1" = 1000' KENNEDY DRIVE & TWO BROTHERS DRIVE South Burlington, Vermont Consulting Engineers, INC. 4 Main StrHHt SuitH 20 &oOFhHstHr VT 044 P 802 880 _ F 802 8898 HPaiO#krHEsandOansinJFoP _ krHEsandOansinJFoP HILLSIDE @ O'BRIEN FARM LOTS 11-15 Hillside @ O’Brien Farm – Lots 11-15 Stormwater Narrative 6 Soils Map [Insert project specific soils map here. Soils information can be found at the Web Soil Survey website. Hydrologic Soil Groups— “HSGs” shall be overlaid with site outline. Soils information can also be provided as data layer on an existing or proposed condition plan sheet (if included as a data layer on one of the plan sheets please indicate that here] See Attached Soils Map. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Chittenden County, Vermont Survey Area Data: Version 19, Sep 15, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 28, 2010—Oct 8, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—Chittenden County, Vermont (O'Brien Home Farm) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/11/2017 Page 2 of 3 Map Unit Legend Chittenden County, Vermont (VT007) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AdA Adams and Windsor loamy sands, 0 to 5 percent slopes 52.6 15.3% AdB Adams and Windsor loamy sands, 5 to 12 percent slopes 52.3 15.2% AdD Adams and Windsor loamy sands, 12 to 30 percent slopes 24.5 7.1% AdE Adams and Windsor loamy sands, 30 to 60 percent slopes 9.0 2.6% Be Beaches 0.3 0.1% BlB Belgrade and Eldridge soils, 3 to 8 percent slopes 2.5 0.7% Cv Covington silty clay 7.6 2.2% DdA Duane and Deerfield soils, 0 to 5 percent slopes 38.7 11.2% DdB Duane and Deerfield soils, 5 to 12 percent slopes 1.8 0.5% EwA Enosburg and Whately soils, 0 to 3 percent slopes 5.0 1.4% EwB Enosburg and Whately soils, 3 to 8 percent slopes 50.1 14.6% FaC Farmington extremely rocky loam, 5 to 20 percent slopes 13.7 4.0% FsB Farmington-Stockbridge rocky loams, 5 to 12 percent slopes 30.4 8.8% HnB Hinesburg fine sandy loam, 3 to 8 percent slopes 10.0 2.9% Lf Limerick silt loam, very wet 17.4 5.1% Lh Livingston clay 2.6 0.7% VeB Vergennes clay, 2 to 6 percent slopes 20.1 5.8% VeC Vergennes clay, 6 to 12 percent slopes 5.5 1.6% VeD Vergennes clay, 12 to 25 percent slopes 0.1 0.0% Totals for Area of Interest 344.2 100.0% Soil Map—Chittenden County, Vermont O'Brien Home Farm Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/11/2017 Page 3 of 3 WQv Grass Channels, Pond A, Infiltration A Unchanged Infiltration Trenches Unchanged 34S SWMA38S GCA1 39S GCA2 40S GCA3 75S CB63/64 76S CB65/66 77S CB66/67 78S CB65A/66A 103S SWMB 128S SWMC 35R GC-A1 36R GC-A2 37R GC-A3 37P Pond A 38P Infiltration A 79P Infiltration Trench63 80P Infiltration Trench65 81P Infiltration Trench67 82P Infiltration Trench65A 127P GravelWet1 129P GravelWet2 49L Study2 67L SN4 Routing Diagram for Hillside2020-postPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (34S, 38S, 39S, 40S, 75S, 76S, 77S, 78S) 0.370 61 >75% Grass cover, Good, HSG B (34S) 3.520 74 >75% Grass cover, Good, HSG C (34S) 4.160 80 >75% Grass cover, Good, HSG D (34S, 38S, 39S) 4.670 98 Paved parking, HSG A (34S, 75S, 76S, 77S, 78S) 3.810 98 Roofs, HSG A (34S, 38S, 39S, 40S) 0.200 98 Water Surface, 0% imp, HSG A (34S) 0.730 30 Woods, Good, HSG A (34S, 38S, 39S) 0.910 77 Woods, Good, HSG D (34S, 38S, 39S) 9.120 96 Workbook (103S, 128S) 33.820 79 TOTAL AREA Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=0.30"Subcatchment 34S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=9.48 cfs 0.515 af Runoff Area=1.940 ac Runoff Depth=0.15"Subcatchment 38S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=0.42 cfs 0.024 af Runoff Area=1.200 ac Runoff Depth=0.14"Subcatchment 39S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=0.28 cfs 0.014 af Runoff Area=0.650 ac Runoff Depth=0.54"Subcatchment 40S: GCA3 Tc=1.0 min CN=79 Runoff=0.67 cfs 0.029 af Runoff Area=0.170 ac Runoff Depth=0.65"Subcatchment 75S: CB63/64 Tc=1.0 min CN=88 Runoff=0.21 cfs 0.009 af Runoff Area=0.100 ac Runoff Depth=0.63"Subcatchment 76S: CB65/66 Tc=1.0 min CN=86 Runoff=0.12 cfs 0.005 af Runoff Area=0.170 ac Runoff Depth=0.65"Subcatchment 77S: CB66/67 Tc=1.0 min CN=88 Runoff=0.21 cfs 0.009 af Runoff Area=0.110 ac Runoff Depth=0.65"Subcatchment 78S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.14 cfs 0.006 af Runoff Area=2.060 ac Runoff Depth=0.63"Subcatchment 103S: SWMB Tc=4.1 min CN=96 Runoff=2.42 cfs 0.108 af Runoff Area=7.060 ac Runoff Depth=0.63"Subcatchment 128S: SWMC Tc=4.3 min CN=96 Runoff=8.25 cfs 0.371 af Avg. Flow Depth=0.12' Max Vel=0.30 fps Inflow=0.42 cfs 0.024 afReach 35R: GC-A1 n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs Outflow=0.19 cfs 0.024 af Avg. Flow Depth=0.11' Max Vel=0.39 fps Inflow=0.28 cfs 0.014 afReach 36R: GC-A2 n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs Outflow=0.19 cfs 0.014 af Avg. Flow Depth=0.21' Max Vel=0.41 fps Inflow=0.67 cfs 0.029 afReach 37R: GC-A3 n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs Outflow=0.31 cfs 0.029 af Peak Elev=332.01' Storage=34,201 cf Inflow=9.60 cfs 0.582 afPond 37P: Pond A Outflow=1.91 cfs 0.582 af Peak Elev=331.01' Storage=62 cf Inflow=1.91 cfs 0.582 afPond 38P: Infiltration A Discarded=1.91 cfs 0.582 af Primary=0.00 cfs 0.000 af Outflow=1.91 cfs 0.582 af Peak Elev=347.67' Storage=82 cf Inflow=0.21 cfs 0.009 afPond 79P: Infiltration Trench63 Discarded=0.06 cfs 0.009 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.009 af Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Peak Elev=334.52' Storage=36 cf Inflow=0.12 cfs 0.005 afPond 80P: Infiltration Trench65 Discarded=0.04 cfs 0.005 af Primary=0.00 cfs 0.000 af Outflow=0.04 cfs 0.005 af Peak Elev=29.21' Storage=90 cf Inflow=0.21 cfs 0.009 afPond 81P: Infiltration Trench67 Discarded=0.06 cfs 0.009 af Primary=0.00 cfs 0.000 af Outflow=0.06 cfs 0.009 af Peak Elev=341.54' Storage=52 cf Inflow=0.14 cfs 0.006 afPond 82P: Infiltration Trench65A Discarded=0.04 cfs 0.006 af Primary=0.00 cfs 0.000 af Outflow=0.04 cfs 0.006 af Peak Elev=327.23' Storage=4,903 cf Inflow=2.42 cfs 0.108 afPond 127P: GravelWet1 Outflow=0.06 cfs 0.108 af Peak Elev=332.00' Storage=17,429 cf Inflow=8.25 cfs 0.371 afPond 129P: GravelWet2 Outflow=0.18 cfs 0.371 af Inflow=0.24 cfs 0.479 afLink 49L: Study2 Primary=0.24 cfs 0.479 af Inflow=0.24 cfs 0.479 afLink 67L: SN4 Primary=0.24 cfs 0.479 af Total Runoff Area = 33.820 ac Runoff Volume = 1.090 af Average Runoff Depth = 0.39" Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 34S: SWMA Runoff = 9.48 cfs @ 11.98 hrs, Volume= 0.515 af, Depth= 0.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 34S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=20.360 ac Runoff Volume=0.515 af Runoff Depth=0.30" Flow Length=1,465' Tc=6.8 min CN=74 9.48 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 38S: GCA1 Runoff = 0.42 cfs @ 11.96 hrs, Volume= 0.024 af, Depth= 0.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 38S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=1.940 ac Runoff Volume=0.024 af Runoff Depth=0.15" Flow Length=168' Tc=4.5 min CN=67 0.42 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 39S: GCA2 Runoff = 0.28 cfs @ 11.95 hrs, Volume= 0.014 af, Depth= 0.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 39S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=1.200 ac Runoff Volume=0.014 af Runoff Depth=0.14" Flow Length=138' Tc=4.5 min CN=51 0.28 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 40S: GCA3 Runoff = 0.67 cfs @ 11.91 hrs, Volume= 0.029 af, Depth= 0.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 40S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=0.650 ac Runoff Volume=0.029 af Runoff Depth=0.54" Tc=1.0 min CN=79 0.67 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 75S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 0.21 cfs @ 11.91 hrs, Volume= 0.009 af, Depth= 0.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 75S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=0.170 ac Runoff Volume=0.009 af Runoff Depth=0.65" Tc=1.0 min CN=88 0.21 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 76S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.12 cfs @ 11.91 hrs, Volume= 0.005 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 76S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=0.100 ac Runoff Volume=0.005 af Runoff Depth=0.63" Tc=1.0 min CN=86 0.12 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 77S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 0.21 cfs @ 11.91 hrs, Volume= 0.009 af, Depth= 0.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 77S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=0.170 ac Runoff Volume=0.009 af Runoff Depth=0.65" Tc=1.0 min CN=88 0.21 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 78S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.14 cfs @ 11.91 hrs, Volume= 0.006 af, Depth= 0.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 78S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=0.110 ac Runoff Volume=0.006 af Runoff Depth=0.65" Tc=1.0 min CN=87 0.14 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 103S: SWMB Runoff = 2.42 cfs @ 11.95 hrs, Volume= 0.108 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description * 2.060 96 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.1 Direct Entry, Workbook- Lag Subcatchment 103S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=2.060 ac Runoff Volume=0.108 af Runoff Depth=0.63" Tc=4.1 min CN=96 2.42 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 128S: SWMC Runoff = 8.25 cfs @ 11.95 hrs, Volume= 0.371 af, Depth= 0.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr WQv-1inch Rainfall=1.00" Area (ac) CN Description * 7.060 96 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.3 Direct Entry, Workbook-Lag Subcatchment 128S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)9 8 7 6 5 4 3 2 1 0 Type II 24-hr WQv-1inch Rainfall=1.00" Runoff Area=7.060 ac Runoff Volume=0.371 af Runoff Depth=0.63" Tc=4.3 min CN=96 8.25 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 35R: GC-A1 Inflow Area = 1.940 ac, Inflow Depth = 0.15" for WQv-1inch event Inflow = 0.42 cfs @ 11.96 hrs, Volume= 0.024 af Outflow = 0.19 cfs @ 12.45 hrs, Volume= 0.024 af, Atten= 54%, Lag= 29.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.30 fps, Min. Travel Time= 24.6 min Avg. Velocity = 0.08 fps, Avg. Travel Time= 88.0 min Peak Storage= 285 cf @ 12.04 hrs Average Depth at Peak Storage= 0.12' Bank-Full Depth= 1.08' Flow Area= 8.9 sf, Capacity= 9.42 cfs 5.00' x 1.08' deep channel, n= 0.120 Side Slope Z-value= 3.0 '/' Top Width= 11.48' Length= 440.0' Slope= 0.0107 '/' Inlet Invert= 361.70', Outlet Invert= 357.00' ‡ Reach 35R: GC-A1 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=1.940 ac Avg. Flow Depth=0.12' Max Vel=0.30 fps n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs 0.42 cfs 0.19 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 18HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 36R: GC-A2 Inflow Area = 1.200 ac, Inflow Depth = 0.14" for WQv-1inch event Inflow = 0.28 cfs @ 11.95 hrs, Volume= 0.014 af Outflow = 0.19 cfs @ 12.19 hrs, Volume= 0.014 af, Atten= 30%, Lag= 14.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.39 fps, Min. Travel Time= 10.6 min Avg. Velocity = 0.10 fps, Avg. Travel Time= 42.0 min Peak Storage= 124 cf @ 12.01 hrs Average Depth at Peak Storage= 0.11' Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 9.60 cfs 4.00' x 1.00' deep channel, n= 0.150 Side Slope Z-value= 3.0 '/' Top Width= 10.00' Length= 252.0' Slope= 0.0321 '/' Inlet Invert= 365.10', Outlet Invert= 357.00' ‡ Reach 36R: GC-A2 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=1.200 ac Avg. Flow Depth=0.11' Max Vel=0.39 fps n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs 0.28 cfs 0.19 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 19HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 37R: GC-A3 Inflow Area = 0.650 ac, Inflow Depth = 0.54" for WQv-1inch event Inflow = 0.67 cfs @ 11.91 hrs, Volume= 0.029 af Outflow = 0.31 cfs @ 12.33 hrs, Volume= 0.029 af, Atten= 54%, Lag= 25.2 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.41 fps, Min. Travel Time= 21.1 min Avg. Velocity = 0.09 fps, Avg. Travel Time= 93.1 min Peak Storage= 396 cf @ 11.98 hrs Average Depth at Peak Storage= 0.21' Bank-Full Depth= 1.00' Flow Area= 6.0 sf, Capacity= 5.84 cfs 3.00' x 1.00' deep channel, n= 0.125 Side Slope Z-value= 3.0 '/' Top Width= 9.00' Length= 520.0' Slope= 0.0121 '/' Inlet Invert= 342.67', Outlet Invert= 336.40' ‡ Reach 37R: GC-A3 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.650 ac Avg. Flow Depth=0.21' Max Vel=0.41 fps n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs 0.67 cfs 0.31 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 20HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 37P: Pond A Inflow Area = 24.150 ac, Inflow Depth = 0.29" for WQv-1inch event Inflow = 9.60 cfs @ 11.98 hrs, Volume= 0.582 af Outflow = 1.91 cfs @ 12.21 hrs, Volume= 0.582 af, Atten= 80%, Lag= 13.7 min Primary = 1.91 cfs @ 12.21 hrs, Volume= 0.582 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 331.25' Surf.Area= 13,348 sf Storage= 23,564 cf Peak Elev= 332.01' @ 12.21 hrs Surf.Area= 14,589 sf Storage= 34,201 cf (10,638 cf above start) Plug-Flow detention time= 1,642.7 min calculated for 0.041 af (7% of inflow) Center-of-Mass det. time= 193.2 min ( 998.8 - 805.6 ) Volume Invert Avail.Storage Storage Description #1 327.25' 120,624 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 327.25 37 0 0 327.75 2,014 513 513 328.00 2,516 566 1,079 329.00 4,793 3,655 4,734 330.00 6,677 5,735 10,469 331.00 12,941 9,809 20,278 332.00 14,567 13,754 34,032 333.00 16,466 15,517 49,548 334.00 18,587 17,527 67,075 335.00 20,824 19,706 86,780 336.00 23,135 21,980 108,760 336.50 24,321 11,864 120,624 Device Routing Invert Outlet Devices #1 Primary 331.15'15.0" Round Culvert L= 20.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 331.15' / 331.00' S= 0.0075 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 331.25'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.75'48.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 #4 Primary 335.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=1.91 cfs @ 12.21 hrs HW=332.01' (Free Discharge) 1=Culvert (Passes 1.91 cfs of 2.02 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.91 cfs @ 2.97 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 21HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 37P: Pond A Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 Inflow Area=24.150 ac Peak Elev=332.01' Storage=34,201 cf 9.60 cfs 1.91 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 22HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 38P: Infiltration A Inflow Area = 24.150 ac, Inflow Depth = 0.29" for WQv-1inch event Inflow = 1.91 cfs @ 12.21 hrs, Volume= 0.582 af Outflow = 1.91 cfs @ 12.22 hrs, Volume= 0.582 af, Atten= 0%, Lag= 0.6 min Discarded = 1.91 cfs @ 12.22 hrs, Volume= 0.582 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 331.01' @ 12.22 hrs Surf.Area= 7,025 sf Storage= 62 cf Plug-Flow detention time= 0.5 min calculated for 0.582 af (100% of inflow) Center-of-Mass det. time= 0.5 min ( 999.3 - 998.8 ) Volume Invert Avail.Storage Storage Description #1 331.00' 27,230 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,013 0 0 332.00 8,357 7,685 7,685 333.00 9,758 9,058 16,743 334.00 11,216 10,487 27,230 Device Routing Invert Outlet Devices #1 Discarded 331.00'40.000 in/hr Exfiltration over Surface area below 331.01' #2 Primary 331.75'6.0" Vert. Orifice/Grate C= 0.600 #3 Primary 333.25'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Discarded OutFlow Max=6.50 cfs @ 12.22 hrs HW=331.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 6.50 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=331.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 23HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 38P: Infiltration A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Inflow Area=24.150 ac Peak Elev=331.01' Storage=62 cf 1.91 cfs1.91 cfs1.91 cfs 0.00 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 24HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 79P: Infiltration Trench63 Inflow Area = 0.170 ac, Inflow Depth = 0.65" for WQv-1inch event Inflow = 0.21 cfs @ 11.91 hrs, Volume= 0.009 af Outflow = 0.06 cfs @ 11.70 hrs, Volume= 0.009 af, Atten= 72%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.70 hrs, Volume= 0.009 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 347.67' @ 12.00 hrs Surf.Area= 102 sf Storage= 82 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 5.8 min ( 785.7 - 780.0 ) Volume Invert Avail.Storage Storage Description #1 352.80' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 346.18' 72 cf 3.25'W x 31.50'L x 2.42'H Field A 248 cf Overall - 67 cf Embedded = 181 cf x 40.0% Voids #3A 346.51' 54 cf ADS N-12 18 x 2 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 156 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 352.80 20 0 0 353.30 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 346.18'25.000 in/hr Exfiltration over Surface area below 346.19' #2 Primary 348.09'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.70 hrs HW=346.26' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=346.18' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 25HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 79P: Infiltration Trench63 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 2 Chambers/Row x 20.00' Long -10.00' Row Adjustment = 30.00' Row Length +9.0" End Stone x 2 = 31.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 2 Chambers x 36.0 cf -10.00' Row Adjustment x 1.80 sf x 1 Rows = 54.0 cf Chamber Storage 2 Chambers x 44.5 cf -10.00' Row Adjustment x 2.23 sf x 1 Rows = 66.8 cf Displacement 247.5 cf Field - 66.8 cf Chambers = 180.7 cf Stone x 40.0% Voids = 72.3 cf Stone Storage Chamber Storage + Stone Storage = 126.3 cf = 0.003 af Overall Storage Efficiency = 51.0% 2 Chambers 9.2 cy Field 6.7 cy Stone Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 26HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 79P: Infiltration Trench63 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.170 ac Peak Elev=347.67' Storage=82 cf 0.21 cfs 0.06 cfs0.06 cfs 0.00 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 27HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 80P: Infiltration Trench65 Inflow Area = 0.100 ac, Inflow Depth = 0.63" for WQv-1inch event Inflow = 0.12 cfs @ 11.91 hrs, Volume= 0.005 af Outflow = 0.04 cfs @ 11.75 hrs, Volume= 0.005 af, Atten= 64%, Lag= 0.0 min Discarded = 0.04 cfs @ 11.75 hrs, Volume= 0.005 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Peak Elev= 334.52' @ 11.99 hrs Surf.Area= 76 sf Storage= 36 cf Plug-Flow detention time= 3.2 min calculated for 0.005 af (100% of inflow) Center-of-Mass det. time= 3.2 min ( 783.2 - 780.0 ) Volume Invert Avail.Storage Storage Description #1 339.60' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 333.52' 54 cf 3.25'W x 23.50'L x 2.42'H Field A 185 cf Overall - 49 cf Embedded = 136 cf x 40.0% Voids #3A 333.85' 40 cf ADS N-12 18 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 124 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 339.60 20 0 0 340.10 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 333.52'25.000 in/hr Exfiltration over Surface area below 333.53' #2 Primary 335.35'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.75 hrs HW=333.59' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=333.52' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 28HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 80P: Infiltration Trench65 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +9.0" End Stone x 2 = 23.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 1 Chambers x 36.0 cf +2.00' Row Adjustment x 1.80 sf x 1 Rows = 39.6 cf Chamber Storage 1 Chambers x 44.5 cf +2.00' Row Adjustment x 2.23 sf x 1 Rows = 49.0 cf Displacement 184.6 cf Field - 49.0 cf Chambers = 135.7 cf Stone x 40.0% Voids = 54.3 cf Stone Storage Chamber Storage + Stone Storage = 93.9 cf = 0.002 af Overall Storage Efficiency = 50.8% 1 Chambers 6.8 cy Field 5.0 cy Stone Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 29HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 80P: Infiltration Trench65 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.100 ac Peak Elev=334.52' Storage=36 cf 0.12 cfs 0.04 cfs0.04 cfs 0.00 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 30HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 81P: Infiltration Trench67 Inflow Area = 0.170 ac, Inflow Depth = 0.65" for WQv-1inch event Inflow = 0.21 cfs @ 11.91 hrs, Volume= 0.009 af Outflow = 0.06 cfs @ 11.74 hrs, Volume= 0.009 af, Atten= 72%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.74 hrs, Volume= 0.009 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 29.21' @ 12.00 hrs Surf.Area= 103 sf Storage= 90 cf Plug-Flow detention time= 8.5 min calculated for 0.009 af (100% of inflow) Center-of-Mass det. time= 8.5 min ( 788.5 - 780.0 ) Volume Invert Avail.Storage Storage Description #1 333.27' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 27.52' 67 cf 2.83'W x 36.33'L x 2.17'H Field A 223 cf Overall - 56 cf Embedded = 167 cf x 40.0% Voids #3A 27.85' 42 cf ADS N-12 15 x 2 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 139 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 333.27 20 0 0 333.77 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 27.52'25.000 in/hr Exfiltration over Surface area below 327.53' #2 Primary 329.02'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.74 hrs HW=27.85' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=27.52' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 31HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 81P: Infiltration Trench67 - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 2 Chambers/Row x 20.00' Long -5.00' Row Adjustment = 35.00' Row Length +8.0" End Stone x 2 = 36.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 2 Chambers x 24.0 cf -5.00' Row Adjustment x 1.20 sf x 1 Rows = 42.0 cf Chamber Storage 2 Chambers x 31.9 cf -5.00' Row Adjustment x 1.60 sf x 1 Rows = 55.9 cf Displacement 222.9 cf Field - 55.9 cf Chambers = 167.1 cf Stone x 40.0% Voids = 66.8 cf Stone Storage Chamber Storage + Stone Storage = 108.8 cf = 0.002 af Overall Storage Efficiency = 48.8% 2 Chambers 8.3 cy Field 6.2 cy Stone Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 32HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 81P: Infiltration Trench67 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.170 ac Peak Elev=29.21' Storage=90 cf 0.21 cfs 0.06 cfs0.06 cfs 0.00 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 33HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 82P: Infiltration Trench65A Inflow Area = 0.110 ac, Inflow Depth = 0.65" for WQv-1inch event Inflow = 0.14 cfs @ 11.91 hrs, Volume= 0.006 af Outflow = 0.04 cfs @ 11.70 hrs, Volume= 0.006 af, Atten= 72%, Lag= 0.0 min Discarded = 0.04 cfs @ 11.70 hrs, Volume= 0.006 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 341.54' @ 12.00 hrs Surf.Area= 66 sf Storage= 52 cf Plug-Flow detention time= 5.7 min calculated for 0.006 af (100% of inflow) Center-of-Mass det. time= 5.6 min ( 785.6 - 780.0 ) Volume Invert Avail.Storage Storage Description #1 345.68' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 340.02' 43 cf 2.83'W x 23.33'L x 2.17'H Field A 143 cf Overall - 35 cf Embedded = 108 cf x 40.0% Voids #3A 340.35' 26 cf ADS N-12 15 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 100 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 345.68 20 0 0 346.18 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 340.02'25.000 in/hr Exfiltration over Surface area below 340.03' #2 Primary 341.60'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.70 hrs HW=340.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=340.02' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 34HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 82P: Infiltration Trench65A - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +8.0" End Stone x 2 = 23.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 1 Chambers x 24.0 cf +2.00' Row Adjustment x 1.20 sf x 1 Rows = 26.4 cf Chamber Storage 1 Chambers x 31.9 cf +2.00' Row Adjustment x 1.60 sf x 1 Rows = 35.1 cf Displacement 143.2 cf Field - 35.1 cf Chambers = 108.1 cf Stone x 40.0% Voids = 43.2 cf Stone Storage Chamber Storage + Stone Storage = 69.6 cf = 0.002 af Overall Storage Efficiency = 48.6% 1 Chambers 5.3 cy Field 4.0 cy Stone Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 35HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 82P: Infiltration Trench65A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.110 ac Peak Elev=341.54' Storage=52 cf 0.14 cfs 0.04 cfs0.04 cfs 0.00 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 36HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 127P: GravelWet1 Inflow Area = 2.610 ac, Inflow Depth = 0.50" for WQv-1inch event Inflow = 2.42 cfs @ 11.95 hrs, Volume= 0.108 af Outflow = 0.06 cfs @ 14.70 hrs, Volume= 0.108 af, Atten= 98%, Lag= 165.3 min Primary = 0.06 cfs @ 14.70 hrs, Volume= 0.108 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 326.17' Surf.Area= 4,400 sf Storage= 2,125 cf Peak Elev= 327.23' @ 14.70 hrs Surf.Area= 9,090 sf Storage= 4,903 cf (2,778 cf above start) Plug-Flow detention time= 972.9 min calculated for 0.059 af (55% of inflow) Center-of-Mass det. time= 525.3 min ( 1,334.6 - 809.3 ) Volume Invert Avail.Storage Storage Description #1 323.50' 2,050 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,126 cf Overall x 40.0% Voids #2 325.83' 147 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,474 cf Overall x 10.0% Voids #3 326.50' 20,418 cf Custom Stage Data (Prismatic) Listed below (Recalc) 22,616 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 323.50 2,200 0 0 325.83 2,200 5,126 5,126 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 325.83 2,200 0 0 326.50 2,200 1,474 1,474 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 326.50 2,200 0 0 327.00 4,413 1,653 1,653 328.00 5,610 5,012 6,665 329.00 6,862 6,236 12,901 330.00 8,172 7,517 20,418 Device Routing Invert Outlet Devices #1 Primary 326.17'18.0" Round Culvert L= 75.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 326.17' / 325.80' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 326.17'1.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 327.30'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 328.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 37HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Primary OutFlow Max=0.06 cfs @ 14.70 hrs HW=327.23' (Free Discharge) 1=Culvert (Passes 0.06 cfs of 3.40 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.06 cfs @ 4.81 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) Pond 127P: GravelWet1 Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Inflow Area=2.610 ac Peak Elev=327.23' Storage=4,903 cf 2.42 cfs 0.06 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 38HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 129P: GravelWet2 Inflow Area = 7.060 ac, Inflow Depth = 0.63" for WQv-1inch event Inflow = 8.25 cfs @ 11.95 hrs, Volume= 0.371 af Outflow = 0.18 cfs @ 15.18 hrs, Volume= 0.371 af, Atten= 98%, Lag= 194.0 min Primary = 0.18 cfs @ 15.18 hrs, Volume= 0.371 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 330.67' Surf.Area= 15,488 sf Storage= 7,481 cf Peak Elev= 332.00' @ 15.18 hrs Surf.Area= 27,034 sf Storage= 17,429 cf (9,948 cf above start) Plug-Flow detention time= 1,140.0 min calculated for 0.199 af (54% of inflow) Center-of-Mass det. time= 630.3 min ( 1,439.8 - 809.5 ) Volume Invert Avail.Storage Storage Description #1 328.00' 7,217 cf Custom Stage Data (Prismatic) Listed below (Recalc) 18,044 cf Overall x 40.0% Voids #2 330.33' 519 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,188 cf Overall x 10.0% Voids #3 331.00' 44,909 cf Custom Stage Data (Prismatic) Listed below (Recalc) 52,645 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 328.00 7,744 0 0 330.33 7,744 18,044 18,044 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 330.33 7,744 0 0 331.00 7,744 5,188 5,188 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,744 0 0 332.00 11,537 9,641 9,641 333.00 13,558 12,548 22,188 334.00 15,674 14,616 36,804 334.50 16,744 8,105 44,909 Device Routing Invert Outlet Devices #1 Primary 330.67'18.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 330.67' / 329.00' S= 0.1113 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 330.67'2.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.00'1.0" Vert. Orifice/Grate C= 0.600 #4 Primary 333.00'6.0" Vert. Orifice/Grate C= 0.600 #5 Device 1 333.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #6 Primary 333.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 39HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.18 cfs @ 15.18 hrs HW=332.00' (Free Discharge) 1=Culvert (Passes 0.18 cfs of 5.16 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.18 cfs @ 5.34 fps) 3=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.23 fps) 5=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 129P: GravelWet2 InflowPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)9 8 7 6 5 4 3 2 1 0 Inflow Area=7.060 ac Peak Elev=332.00' Storage=17,429 cf 8.25 cfs 0.18 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 40HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 49L: Study2 Inflow Area = 33.820 ac, Inflow Depth = 0.17" for WQv-1inch event Inflow = 0.24 cfs @ 15.11 hrs, Volume= 0.479 af Primary = 0.24 cfs @ 15.11 hrs, Volume= 0.479 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 49L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=33.820 ac 0.24 cfs0.24 cfs Type II 24-hr WQv-1inch Rainfall=1.00"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 41HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 67L: SN4 Inflow Area = 33.820 ac, Inflow Depth = 0.17" for WQv-1inch event Inflow = 0.24 cfs @ 15.11 hrs, Volume= 0.479 af Primary = 0.24 cfs @ 15.11 hrs, Volume= 0.479 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 67L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=33.820 ac 0.24 cfs0.24 cfs CPv Grass Channels, Pond A, Infiltration A Unchanged Infiltration Trenches Unchanged 130S SWMA131S GCA1 132S GCA2 133S GCA3 134S CB63/64 135S CB65/66 136S CB66/67 137S CB65A/66A 153S SWMB 154S SWMC 140R GC-A1 141R GC-A2 142R GC-A3 143P Pond A 144P Infiltration A 145P Infiltration Trench63 146P Infiltration Trench65 147P Infiltration Trench67 148P Infiltration Trench65A149P GravelWet1 150P GravelWet2 151L Study2 152L SN4 Routing Diagram for Hillside2020-postPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (130S, 131S, 132S, 133S, 134S, 135S, 136S, 137S) 0.370 61 >75% Grass cover, Good, HSG B (130S) 3.520 74 >75% Grass cover, Good, HSG C (130S) 4.160 80 >75% Grass cover, Good, HSG D (130S, 131S, 132S) 4.670 98 Paved parking, HSG A (130S, 134S, 135S, 136S, 137S) 3.810 98 Roofs, HSG A (130S, 131S, 132S, 133S) 0.200 98 Water Surface, 0% imp, HSG A (130S) 0.730 30 Woods, Good, HSG A (130S, 131S, 132S) 0.910 77 Woods, Good, HSG D (130S, 131S, 132S) 2.060 91 Workbook (153S) 7.060 90 Workbook (154S) 33.820 78 TOTAL AREA Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=0.75"Subcatchment 130S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=23.42 cfs 1.272 af Runoff Area=1.940 ac Runoff Depth=0.47"Subcatchment 131S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=1.57 cfs 0.077 af Runoff Area=1.200 ac Runoff Depth=0.34"Subcatchment 132S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=0.68 cfs 0.034 af Runoff Area=0.650 ac Runoff Depth=1.13"Subcatchment 133S: GCA3 Tc=1.0 min CN=79 Runoff=1.35 cfs 0.061 af Runoff Area=0.170 ac Runoff Depth=1.38"Subcatchment 134S: CB63/64 Tc=1.0 min CN=88 Runoff=0.43 cfs 0.020 af Runoff Area=0.100 ac Runoff Depth=1.34"Subcatchment 135S: CB65/66 Tc=1.0 min CN=86 Runoff=0.25 cfs 0.011 af Runoff Area=0.170 ac Runoff Depth=1.38"Subcatchment 136S: CB66/67 Tc=1.0 min CN=88 Runoff=0.43 cfs 0.020 af Runoff Area=0.110 ac Runoff Depth=1.37"Subcatchment 137S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.28 cfs 0.013 af Runoff Area=2.060 ac Runoff Depth=1.08"Subcatchment 153S: SWMB Tc=4.1 min CN=91 Runoff=4.20 cfs 0.185 af Runoff Area=7.060 ac Runoff Depth=1.01"Subcatchment 154S: SWMC Tc=4.3 min CN=90 Runoff=13.49 cfs 0.594 af Avg. Flow Depth=0.29' Max Vel=0.51 fps Inflow=1.57 cfs 0.077 afReach 140R: GC-A1 n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs Outflow=0.88 cfs 0.077 af Avg. Flow Depth=0.20' Max Vel=0.56 fps Inflow=0.68 cfs 0.034 afReach 141R: GC-A2 n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs Outflow=0.52 cfs 0.034 af Avg. Flow Depth=0.34' Max Vel=0.54 fps Inflow=1.35 cfs 0.061 afReach 142R: GC-A3 n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs Outflow=0.73 cfs 0.061 af Peak Elev=332.92' Storage=48,172 cf Inflow=23.91 cfs 1.444 afPond 143P: Pond A Outflow=4.83 cfs 1.444 af Peak Elev=331.02' Storage=157 cf Inflow=4.83 cfs 1.444 afPond 144P: Infiltration A Discarded=4.83 cfs 1.444 af Primary=0.00 cfs 0.000 af Outflow=4.83 cfs 1.444 af Peak Elev=348.37' Storage=117 cf Inflow=0.43 cfs 0.020 afPond 145P: Infiltration Trench63 Discarded=0.06 cfs 0.016 af Primary=0.37 cfs 0.003 af Outflow=0.43 cfs 0.020 af Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Peak Elev=335.55' Storage=82 cf Inflow=0.25 cfs 0.011 afPond 146P: Infiltration Trench65 Discarded=0.04 cfs 0.010 af Primary=0.22 cfs 0.001 af Outflow=0.26 cfs 0.011 af Peak Elev=329.14' Storage=109 cf Inflow=0.43 cfs 0.020 afPond 147P: Infiltration Trench67 Discarded=0.06 cfs 0.016 af Primary=0.44 cfs 0.003 af Outflow=0.50 cfs 0.020 af Peak Elev=341.82' Storage=60 cf Inflow=0.28 cfs 0.013 afPond 148P: Infiltration Trench65A Discarded=0.04 cfs 0.010 af Primary=0.24 cfs 0.002 af Outflow=0.27 cfs 0.013 af Peak Elev=327.76' Storage=7,563 cf Inflow=5.14 cfs 0.195 afPond 149P: GravelWet1 Outflow=0.09 cfs 0.195 af Peak Elev=332.58' Storage=24,367 cf Inflow=13.49 cfs 0.594 afPond 150P: GravelWet2 Outflow=0.24 cfs 0.594 af Inflow=0.33 cfs 0.789 afLink 151L: Study2 Primary=0.33 cfs 0.789 af Inflow=0.33 cfs 0.789 afLink 152L: SN4 Primary=0.33 cfs 0.789 af Total Runoff Area = 33.820 ac Runoff Volume = 2.286 af Average Runoff Depth = 0.81" Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 130S: SWMA Runoff = 23.42 cfs @ 11.98 hrs, Volume= 1.272 af, Depth= 0.75" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 130S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=20.360 ac Runoff Volume=1.272 af Runoff Depth=0.75" Flow Length=1,465' Tc=6.8 min CN=74 23.42 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 131S: GCA1 Runoff = 1.57 cfs @ 11.96 hrs, Volume= 0.077 af, Depth= 0.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 131S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=1.940 ac Runoff Volume=0.077 af Runoff Depth=0.47" Flow Length=168' Tc=4.5 min CN=67 1.57 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 132S: GCA2 Runoff = 0.68 cfs @ 11.95 hrs, Volume= 0.034 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 132S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=1.200 ac Runoff Volume=0.034 af Runoff Depth=0.34" Flow Length=138' Tc=4.5 min CN=51 0.68 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 133S: GCA3 Runoff = 1.35 cfs @ 11.91 hrs, Volume= 0.061 af, Depth= 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 133S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=0.650 ac Runoff Volume=0.061 af Runoff Depth=1.13" Tc=1.0 min CN=79 1.35 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 134S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Depth= 1.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 134S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=0.170 ac Runoff Volume=0.020 af Runoff Depth=1.38" Tc=1.0 min CN=88 0.43 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 135S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.25 cfs @ 11.91 hrs, Volume= 0.011 af, Depth= 1.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 135S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=0.100 ac Runoff Volume=0.011 af Runoff Depth=1.34" Tc=1.0 min CN=86 0.25 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 136S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Depth= 1.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 136S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=0.170 ac Runoff Volume=0.020 af Runoff Depth=1.38" Tc=1.0 min CN=88 0.43 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 137S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.28 cfs @ 11.91 hrs, Volume= 0.013 af, Depth= 1.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 137S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=0.110 ac Runoff Volume=0.013 af Runoff Depth=1.37" Tc=1.0 min CN=87 0.28 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 153S: SWMB Runoff = 4.20 cfs @ 11.95 hrs, Volume= 0.185 af, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description * 2.060 91 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.1 Direct Entry, Workbook- Lag Subcatchment 153S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)4 3 2 1 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=2.060 ac Runoff Volume=0.185 af Runoff Depth=1.08" Tc=4.1 min CN=91 4.20 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 154S: SWMC Runoff = 13.49 cfs @ 11.95 hrs, Volume= 0.594 af, Depth= 1.01" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 1 Year Rainfall=1.90" Area (ac) CN Description * 7.060 90 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.3 Direct Entry, Workbook-Lag Subcatchment 154S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 1 Year Rainfall=1.90" Runoff Area=7.060 ac Runoff Volume=0.594 af Runoff Depth=1.01" Tc=4.3 min CN=90 13.49 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 140R: GC-A1 Inflow Area = 1.940 ac, Inflow Depth = 0.47" for 1 Year event Inflow = 1.57 cfs @ 11.96 hrs, Volume= 0.077 af Outflow = 0.88 cfs @ 12.27 hrs, Volume= 0.077 af, Atten= 44%, Lag= 18.7 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.51 fps, Min. Travel Time= 14.4 min Avg. Velocity = 0.11 fps, Avg. Travel Time= 68.1 min Peak Storage= 761 cf @ 12.03 hrs Average Depth at Peak Storage= 0.29' Bank-Full Depth= 1.08' Flow Area= 8.9 sf, Capacity= 9.42 cfs 5.00' x 1.08' deep channel, n= 0.120 Side Slope Z-value= 3.0 '/' Top Width= 11.48' Length= 440.0' Slope= 0.0107 '/' Inlet Invert= 361.70', Outlet Invert= 357.00' ‡ Reach 140R: GC-A1 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=1.940 ac Avg. Flow Depth=0.29' Max Vel=0.51 fps n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs 1.57 cfs 0.88 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 18HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 141R: GC-A2 Inflow Area = 1.200 ac, Inflow Depth = 0.34" for 1 Year event Inflow = 0.68 cfs @ 11.95 hrs, Volume= 0.034 af Outflow = 0.52 cfs @ 12.13 hrs, Volume= 0.034 af, Atten= 23%, Lag= 10.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.56 fps, Min. Travel Time= 7.5 min Avg. Velocity = 0.12 fps, Avg. Travel Time= 33.8 min Peak Storage= 236 cf @ 12.00 hrs Average Depth at Peak Storage= 0.20' Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 9.60 cfs 4.00' x 1.00' deep channel, n= 0.150 Side Slope Z-value= 3.0 '/' Top Width= 10.00' Length= 252.0' Slope= 0.0321 '/' Inlet Invert= 365.10', Outlet Invert= 357.00' ‡ Reach 141R: GC-A2 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=1.200 ac Avg. Flow Depth=0.20' Max Vel=0.56 fps n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs 0.68 cfs 0.52 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 19HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 142R: GC-A3 Inflow Area = 0.650 ac, Inflow Depth = 1.13" for 1 Year event Inflow = 1.35 cfs @ 11.91 hrs, Volume= 0.061 af Outflow = 0.73 cfs @ 12.24 hrs, Volume= 0.061 af, Atten= 46%, Lag= 19.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.54 fps, Min. Travel Time= 16.1 min Avg. Velocity = 0.11 fps, Avg. Travel Time= 76.7 min Peak Storage= 709 cf @ 11.97 hrs Average Depth at Peak Storage= 0.34' Bank-Full Depth= 1.00' Flow Area= 6.0 sf, Capacity= 5.84 cfs 3.00' x 1.00' deep channel, n= 0.125 Side Slope Z-value= 3.0 '/' Top Width= 9.00' Length= 520.0' Slope= 0.0121 '/' Inlet Invert= 342.67', Outlet Invert= 336.40' ‡ Reach 142R: GC-A3 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=0.650 ac Avg. Flow Depth=0.34' Max Vel=0.54 fps n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs 1.35 cfs 0.73 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 20HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 143P: Pond A Inflow Area = 24.150 ac, Inflow Depth = 0.72" for 1 Year event Inflow = 23.91 cfs @ 11.98 hrs, Volume= 1.444 af Outflow = 4.83 cfs @ 12.29 hrs, Volume= 1.444 af, Atten= 80%, Lag= 18.2 min Primary = 4.83 cfs @ 12.29 hrs, Volume= 1.444 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 331.25' Surf.Area= 13,348 sf Storage= 23,564 cf Peak Elev= 332.92' @ 12.29 hrs Surf.Area= 16,307 sf Storage= 48,172 cf (24,609 cf above start) Plug-Flow detention time= 380.0 min calculated for 0.903 af (63% of inflow) Center-of-Mass det. time= 136.9 min ( 932.3 - 795.3 ) Volume Invert Avail.Storage Storage Description #1 327.25' 120,624 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 327.25 37 0 0 327.75 2,014 513 513 328.00 2,516 566 1,079 329.00 4,793 3,655 4,734 330.00 6,677 5,735 10,469 331.00 12,941 9,809 20,278 332.00 14,567 13,754 34,032 333.00 16,466 15,517 49,548 334.00 18,587 17,527 67,075 335.00 20,824 19,706 86,780 336.00 23,135 21,980 108,760 336.50 24,321 11,864 120,624 Device Routing Invert Outlet Devices #1 Primary 331.15'15.0" Round Culvert L= 20.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 331.15' / 331.00' S= 0.0075 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 331.25'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.75'48.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 #4 Primary 335.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=4.95 cfs @ 12.29 hrs HW=332.92' (Free Discharge) 1=Culvert (Passes 4.95 cfs of 4.98 cfs potential flow) 2=Orifice/Grate (Orifice Controls 4.08 cfs @ 5.20 fps) 3=Orifice/Grate (Orifice Controls 0.87 cfs @ 1.31 fps) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 21HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 143P: Pond A Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=24.150 ac Peak Elev=332.92' Storage=48,172 cf 23.91 cfs 4.83 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 22HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 144P: Infiltration A Inflow Area = 24.150 ac, Inflow Depth = 0.72" for 1 Year event Inflow = 4.83 cfs @ 12.29 hrs, Volume= 1.444 af Outflow = 4.83 cfs @ 12.29 hrs, Volume= 1.444 af, Atten= 0%, Lag= 0.5 min Discarded = 4.83 cfs @ 12.29 hrs, Volume= 1.444 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 331.02' @ 12.29 hrs Surf.Area= 7,043 sf Storage= 157 cf Plug-Flow detention time= 0.5 min calculated for 1.444 af (100% of inflow) Center-of-Mass det. time= 0.5 min ( 932.8 - 932.3 ) Volume Invert Avail.Storage Storage Description #1 331.00' 27,230 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,013 0 0 332.00 8,357 7,685 7,685 333.00 9,758 9,058 16,743 334.00 11,216 10,487 27,230 Device Routing Invert Outlet Devices #1 Discarded 331.00'40.000 in/hr Exfiltration over Surface area below 331.01' #2 Primary 331.75'6.0" Vert. Orifice/Grate C= 0.600 #3 Primary 333.25'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Discarded OutFlow Max=6.51 cfs @ 12.29 hrs HW=331.02' (Free Discharge) 1=Exfiltration (Exfiltration Controls 6.51 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=331.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 23HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 144P: Infiltration A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)5 4 3 2 1 0 Inflow Area=24.150 ac Peak Elev=331.02' Storage=157 cf 4.83 cfs4.83 cfs4.83 cfs 0.00 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 24HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 145P: Infiltration Trench63 Inflow Area = 0.170 ac, Inflow Depth = 1.38" for 1 Year event Inflow = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af Outflow = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Atten= 1%, Lag= 0.3 min Discarded = 0.06 cfs @ 11.58 hrs, Volume= 0.016 af Primary = 0.37 cfs @ 11.91 hrs, Volume= 0.003 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 348.37' @ 11.91 hrs Surf.Area= 102 sf Storage= 117 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 6.9 min ( 767.4 - 760.5 ) Volume Invert Avail.Storage Storage Description #1 352.80' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 346.18' 72 cf 3.25'W x 31.50'L x 2.42'H Field A 248 cf Overall - 67 cf Embedded = 181 cf x 40.0% Voids #3A 346.51' 54 cf ADS N-12 18 x 2 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 156 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 352.80 20 0 0 353.30 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 346.18'25.000 in/hr Exfiltration over Surface area below 346.19' #2 Primary 348.09'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.58 hrs HW=346.25' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.36 cfs @ 11.91 hrs HW=348.37' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.36 cfs @ 1.79 fps) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 25HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 145P: Infiltration Trench63 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 2 Chambers/Row x 20.00' Long -10.00' Row Adjustment = 30.00' Row Length +9.0" End Stone x 2 = 31.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 2 Chambers x 36.0 cf -10.00' Row Adjustment x 1.80 sf x 1 Rows = 54.0 cf Chamber Storage 2 Chambers x 44.5 cf -10.00' Row Adjustment x 2.23 sf x 1 Rows = 66.8 cf Displacement 247.5 cf Field - 66.8 cf Chambers = 180.7 cf Stone x 40.0% Voids = 72.3 cf Stone Storage Chamber Storage + Stone Storage = 126.3 cf = 0.003 af Overall Storage Efficiency = 51.0% 2 Chambers 9.2 cy Field 6.7 cy Stone Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 26HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 145P: Infiltration Trench63 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.170 ac Peak Elev=348.37' Storage=117 cf 0.43 cfs0.43 cfs 0.06 cfs 0.37 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 27HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 146P: Infiltration Trench65 Inflow Area = 0.100 ac, Inflow Depth = 1.34" for 1 Year event Inflow = 0.25 cfs @ 11.91 hrs, Volume= 0.011 af Outflow = 0.26 cfs @ 11.91 hrs, Volume= 0.011 af, Atten= 0%, Lag= 0.3 min Discarded = 0.04 cfs @ 11.61 hrs, Volume= 0.010 af Primary = 0.22 cfs @ 11.91 hrs, Volume= 0.001 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Peak Elev= 335.55' @ 11.91 hrs Surf.Area= 76 sf Storage= 82 cf Plug-Flow detention time= 6.9 min calculated for 0.011 af (100% of inflow) Center-of-Mass det. time= 6.9 min ( 767.4 - 760.5 ) Volume Invert Avail.Storage Storage Description #1 339.60' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 333.52' 54 cf 3.25'W x 23.50'L x 2.42'H Field A 185 cf Overall - 49 cf Embedded = 136 cf x 40.0% Voids #3A 333.85' 40 cf ADS N-12 18 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 124 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 339.60 20 0 0 340.10 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 333.52'25.000 in/hr Exfiltration over Surface area below 333.53' #2 Primary 335.35'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.61 hrs HW=333.59' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.20 cfs @ 11.91 hrs HW=335.55' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.20 cfs @ 1.53 fps) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 28HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 146P: Infiltration Trench65 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +9.0" End Stone x 2 = 23.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 1 Chambers x 36.0 cf +2.00' Row Adjustment x 1.80 sf x 1 Rows = 39.6 cf Chamber Storage 1 Chambers x 44.5 cf +2.00' Row Adjustment x 2.23 sf x 1 Rows = 49.0 cf Displacement 184.6 cf Field - 49.0 cf Chambers = 135.7 cf Stone x 40.0% Voids = 54.3 cf Stone Storage Chamber Storage + Stone Storage = 93.9 cf = 0.002 af Overall Storage Efficiency = 50.8% 1 Chambers 6.8 cy Field 5.0 cy Stone Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 29HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 146P: Infiltration Trench65 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.100 ac Peak Elev=335.55' Storage=82 cf 0.25 cfs0.26 cfs 0.04 cfs 0.22 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 30HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 147P: Infiltration Trench67 Inflow Area = 0.170 ac, Inflow Depth = 1.38" for 1 Year event Inflow = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af Outflow = 0.50 cfs @ 11.91 hrs, Volume= 0.020 af, Atten= 0%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.62 hrs, Volume= 0.016 af Primary = 0.44 cfs @ 11.91 hrs, Volume= 0.003 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 329.14' @ 11.91 hrs Surf.Area= 103 sf Storage= 109 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 8.4 min ( 768.9 - 760.5 ) Volume Invert Avail.Storage Storage Description #1 333.27' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 27.52' 67 cf 2.83'W x 36.33'L x 2.17'H Field A 223 cf Overall - 56 cf Embedded = 167 cf x 40.0% Voids #3A 27.85' 42 cf ADS N-12 15 x 2 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 139 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 333.27 20 0 0 333.77 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 27.52'25.000 in/hr Exfiltration over Surface area below 327.53' #2 Primary 329.02'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.62 hrs HW=27.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.07 cfs @ 11.91 hrs HW=329.14' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.07 cfs @ 1.19 fps) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 31HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 147P: Infiltration Trench67 - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 2 Chambers/Row x 20.00' Long -5.00' Row Adjustment = 35.00' Row Length +8.0" End Stone x 2 = 36.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 2 Chambers x 24.0 cf -5.00' Row Adjustment x 1.20 sf x 1 Rows = 42.0 cf Chamber Storage 2 Chambers x 31.9 cf -5.00' Row Adjustment x 1.60 sf x 1 Rows = 55.9 cf Displacement 222.9 cf Field - 55.9 cf Chambers = 167.1 cf Stone x 40.0% Voids = 66.8 cf Stone Storage Chamber Storage + Stone Storage = 108.8 cf = 0.002 af Overall Storage Efficiency = 48.8% 2 Chambers 8.3 cy Field 6.2 cy Stone Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 32HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 147P: Infiltration Trench67 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.170 ac Peak Elev=329.14' Storage=109 cf 0.43 cfs 0.50 cfs 0.06 cfs 0.44 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 33HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 148P: Infiltration Trench65A Inflow Area = 0.110 ac, Inflow Depth = 1.37" for 1 Year event Inflow = 0.28 cfs @ 11.91 hrs, Volume= 0.013 af Outflow = 0.27 cfs @ 11.91 hrs, Volume= 0.013 af, Atten= 1%, Lag= 0.2 min Discarded = 0.04 cfs @ 11.58 hrs, Volume= 0.010 af Primary = 0.24 cfs @ 11.91 hrs, Volume= 0.002 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 341.82' @ 11.91 hrs Surf.Area= 66 sf Storage= 60 cf Plug-Flow detention time= 5.1 min calculated for 0.013 af (100% of inflow) Center-of-Mass det. time= 5.2 min ( 765.7 - 760.5 ) Volume Invert Avail.Storage Storage Description #1 345.68' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 340.02' 43 cf 2.83'W x 23.33'L x 2.17'H Field A 143 cf Overall - 35 cf Embedded = 108 cf x 40.0% Voids #3A 340.35' 26 cf ADS N-12 15 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 100 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 345.68 20 0 0 346.18 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 340.02'25.000 in/hr Exfiltration over Surface area below 340.03' #2 Primary 341.60'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.58 hrs HW=340.08' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.23 cfs @ 11.91 hrs HW=341.82' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.23 cfs @ 1.60 fps) Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 34HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 148P: Infiltration Trench65A - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +8.0" End Stone x 2 = 23.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 1 Chambers x 24.0 cf +2.00' Row Adjustment x 1.20 sf x 1 Rows = 26.4 cf Chamber Storage 1 Chambers x 31.9 cf +2.00' Row Adjustment x 1.60 sf x 1 Rows = 35.1 cf Displacement 143.2 cf Field - 35.1 cf Chambers = 108.1 cf Stone x 40.0% Voids = 43.2 cf Stone Storage Chamber Storage + Stone Storage = 69.6 cf = 0.002 af Overall Storage Efficiency = 48.6% 1 Chambers 5.3 cy Field 4.0 cy Stone Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 35HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 148P: Infiltration Trench65A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.110 ac Peak Elev=341.82' Storage=60 cf 0.28 cfs0.27 cfs 0.04 cfs 0.24 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 36HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 149P: GravelWet1 Inflow Area = 2.610 ac, Inflow Depth = 0.90" for 1 Year event Inflow = 5.14 cfs @ 11.93 hrs, Volume= 0.195 af Outflow = 0.09 cfs @ 15.44 hrs, Volume= 0.195 af, Atten= 98%, Lag= 210.6 min Primary = 0.09 cfs @ 15.44 hrs, Volume= 0.195 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 326.17' Surf.Area= 4,400 sf Storage= 2,125 cf Peak Elev= 327.76' @ 15.44 hrs Surf.Area= 9,726 sf Storage= 7,563 cf (5,438 cf above start) Plug-Flow detention time= 1,076.1 min calculated for 0.146 af (75% of inflow) Center-of-Mass det. time= 747.9 min ( 1,561.2 - 813.2 ) Volume Invert Avail.Storage Storage Description #1 323.50' 2,050 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,126 cf Overall x 40.0% Voids #2 325.83' 147 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,474 cf Overall x 10.0% Voids #3 326.50' 20,418 cf Custom Stage Data (Prismatic) Listed below (Recalc) 22,616 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 323.50 2,200 0 0 325.83 2,200 5,126 5,126 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 325.83 2,200 0 0 326.50 2,200 1,474 1,474 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 326.50 2,200 0 0 327.00 4,413 1,653 1,653 328.00 5,610 5,012 6,665 329.00 6,862 6,236 12,901 330.00 8,172 7,517 20,418 Device Routing Invert Outlet Devices #1 Primary 326.17'18.0" Round Culvert L= 75.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 326.17' / 325.80' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 326.17'1.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 327.30'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 328.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 37HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Primary OutFlow Max=0.09 cfs @ 15.44 hrs HW=327.76' (Free Discharge) 1=Culvert (Passes 0.09 cfs of 6.17 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.07 cfs @ 5.96 fps) 3=Orifice/Grate (Orifice Controls 0.02 cfs @ 3.12 fps) 4=Orifice/Grate ( Controls 0.00 cfs) Pond 149P: GravelWet1 Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)5 4 3 2 1 0 Inflow Area=2.610 ac Peak Elev=327.76' Storage=7,563 cf 5.14 cfs 0.09 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 38HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 150P: GravelWet2 Inflow Area = 7.060 ac, Inflow Depth = 1.01" for 1 Year event Inflow = 13.49 cfs @ 11.95 hrs, Volume= 0.594 af Outflow = 0.24 cfs @ 16.57 hrs, Volume= 0.594 af, Atten= 98%, Lag= 277.1 min Primary = 0.24 cfs @ 16.57 hrs, Volume= 0.594 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 330.67' Surf.Area= 15,488 sf Storage= 7,481 cf Peak Elev= 332.58' @ 16.57 hrs Surf.Area= 28,191 sf Storage= 24,367 cf (16,886 cf above start) Plug-Flow detention time= 1,265.1 min calculated for 0.422 af (71% of inflow) Center-of-Mass det. time= 857.3 min ( 1,681.3 - 824.0 ) Volume Invert Avail.Storage Storage Description #1 328.00' 7,217 cf Custom Stage Data (Prismatic) Listed below (Recalc) 18,044 cf Overall x 40.0% Voids #2 330.33' 519 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,188 cf Overall x 10.0% Voids #3 331.00' 44,909 cf Custom Stage Data (Prismatic) Listed below (Recalc) 52,645 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 328.00 7,744 0 0 330.33 7,744 18,044 18,044 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 330.33 7,744 0 0 331.00 7,744 5,188 5,188 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,744 0 0 332.00 11,537 9,641 9,641 333.00 13,558 12,548 22,188 334.00 15,674 14,616 36,804 334.50 16,744 8,105 44,909 Device Routing Invert Outlet Devices #1 Primary 330.67'18.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 330.67' / 329.00' S= 0.1113 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 330.67'2.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.00'1.0" Vert. Orifice/Grate C= 0.600 #4 Primary 333.00'6.0" Vert. Orifice/Grate C= 0.600 #5 Device 1 333.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #6 Primary 333.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 39HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.24 cfs @ 16.57 hrs HW=332.58' (Free Discharge) 1=Culvert (Passes 0.24 cfs of 7.22 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.22 cfs @ 6.46 fps) 3=Orifice/Grate (Orifice Controls 0.02 cfs @ 3.52 fps) 5=Orifice/Grate ( Controls 0.00 cfs) 4=Orifice/Grate ( Controls 0.00 cfs) 6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 150P: GravelWet2 InflowPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=7.060 ac Peak Elev=332.58' Storage=24,367 cf 13.49 cfs 0.24 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 40HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 151L: Study2 Inflow Area = 33.820 ac, Inflow Depth = 0.28" for 1 Year event Inflow = 0.33 cfs @ 16.01 hrs, Volume= 0.789 af Primary = 0.33 cfs @ 16.01 hrs, Volume= 0.789 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 151L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=33.820 ac 0.33 cfs0.33 cfs Type II 24-hr 1 Year Rainfall=1.90"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 41HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 152L: SN4 Inflow Area = 33.820 ac, Inflow Depth = 0.28" for 1 Year event Inflow = 0.33 cfs @ 16.01 hrs, Volume= 0.789 af Primary = 0.33 cfs @ 16.01 hrs, Volume= 0.789 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 152L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=33.820 ac 0.33 cfs0.33 cfs Qp10 2S Pre2 8L SN4 Routing Diagram for Hillside2020-prePrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Apartments Pre Development Stormwater Model Qp10 & Qp100 Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 19.200 58 Workbook (2S) 19.200 58 TOTAL AREA Type II 24-hr 10 Year Rainfall=3.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19.200 ac Runoff Depth=0.34"Subcatchment 2S: Pre2 Tc=23.4 min CN=58 Runoff=3.46 cfs 0.546 af Inflow=3.46 cfs 0.546 afLink 8L: SN4 Primary=3.46 cfs 0.546 af Total Runoff Area = 19.200 ac Runoff Volume = 0.546 af Average Runoff Depth = 0.34" Type II 24-hr 10 Year Rainfall=3.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Pre2 Area to 24" Culvert on Kennedy Drive east of Windridge Runoff = 3.46 cfs @ 12.25 hrs, Volume= 0.546 af, Depth= 0.34" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 10 Year Rainfall=3.20" Area (ac) CN Description * 19.200 58 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 23.4 Direct Entry, Workbook-Lag Subcatchment 2S: Pre2 Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)3 2 1 0 Type II 24-hr 10 Year Rainfall=3.20" Runoff Area=19.200 ac Runoff Volume=0.546 af Runoff Depth=0.34" Tc=23.4 min CN=58 3.46 cfs Type II 24-hr 10 Year Rainfall=3.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 8L: SN4 Inflow Area = 19.200 ac, Inflow Depth = 0.34" for 10 Year event Inflow = 3.46 cfs @ 12.25 hrs, Volume= 0.546 af Primary = 3.46 cfs @ 12.25 hrs, Volume= 0.546 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Link 8L: SN4 Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086Flow (cfs)3 2 1 0 Inflow Area=19.200 ac 3.46 cfs3.46 cfs Qp10 Grass Channels, Pond A, Infiltration A Unchanged Infiltration Trenches Unchanged 155S SWMA156S GCA1 157S GCA2 158S GCA3 159S CB63/64 160S CB65/66 161S CB66/67 162S CB65A/66A 179S SWMC 180S SWMB 165R GC-A1 166R GC-A2 167R GC-A3 168P Pond A 169P Infiltration A 170P Infiltration Trench63 171P Infiltration Trench65 172P Infiltration Trench67 173P Infiltration Trench65A 174P GravelWet1 175P GravelWet2 176L Study2 177L SN4 Routing Diagram for Hillside2020-postPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (155S, 156S, 157S, 158S, 159S, 160S, 161S, 162S) 0.370 61 >75% Grass cover, Good, HSG B (155S) 3.520 74 >75% Grass cover, Good, HSG C (155S) 4.160 80 >75% Grass cover, Good, HSG D (155S, 156S, 157S) 4.670 98 Paved parking, HSG A (155S, 159S, 160S, 161S, 162S) 3.810 98 Roofs, HSG A (155S, 156S, 157S, 158S) 0.200 98 Water Surface, 0% imp, HSG A (155S) 0.730 30 Woods, Good, HSG A (155S, 156S, 157S) 0.910 77 Woods, Good, HSG D (155S, 156S, 157S) 7.060 87 Workbook (179S) 2.060 88 Workbook (180S) 33.820 77 TOTAL AREA Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=1.55"Subcatchment 155S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=49.02 cfs 2.630 af Runoff Area=1.940 ac Runoff Depth=1.13"Subcatchment 156S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=3.90 cfs 0.183 af Runoff Area=1.200 ac Runoff Depth=0.68"Subcatchment 157S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=1.36 cfs 0.068 af Runoff Area=0.650 ac Runoff Depth=2.04"Subcatchment 158S: GCA3 Tc=1.0 min CN=79 Runoff=2.35 cfs 0.111 af Runoff Area=0.170 ac Runoff Depth=2.49"Subcatchment 159S: CB63/64 Tc=1.0 min CN=88 Runoff=0.75 cfs 0.035 af Runoff Area=0.100 ac Runoff Depth=2.41"Subcatchment 160S: CB65/66 Tc=1.0 min CN=86 Runoff=0.43 cfs 0.020 af Runoff Area=0.170 ac Runoff Depth=2.49"Subcatchment 161S: CB66/67 Tc=1.0 min CN=88 Runoff=0.75 cfs 0.035 af Runoff Area=0.110 ac Runoff Depth=2.47"Subcatchment 162S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.48 cfs 0.023 af Runoff Area=7.060 ac Runoff Depth=1.96"Subcatchment 179S: SWMC Tc=4.9 min CN=87 Runoff=25.28 cfs 1.153 af Runoff Area=2.060 ac Runoff Depth=2.04"Subcatchment 180S: SWMB Tc=4.7 min CN=88 Runoff=7.69 cfs 0.351 af Avg. Flow Depth=0.55' Max Vel=0.73 fps Inflow=3.90 cfs 0.183 afReach 165R: GC-A1 n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs Outflow=2.64 cfs 0.183 af Avg. Flow Depth=0.32' Max Vel=0.72 fps Inflow=1.36 cfs 0.068 afReach 166R: GC-A2 n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs Outflow=1.13 cfs 0.068 af Avg. Flow Depth=0.48' Max Vel=0.65 fps Inflow=2.35 cfs 0.111 afReach 167R: GC-A3 n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs Outflow=1.40 cfs 0.111 af Peak Elev=334.50' Storage=76,708 cf Inflow=50.78 cfs 2.992 afPond 168P: Pond A Outflow=7.70 cfs 2.992 af Peak Elev=331.60' Storage=4,469 cf Inflow=7.70 cfs 2.992 afPond 169P: Infiltration A Discarded=6.51 cfs 2.992 af Primary=0.00 cfs 0.000 af Outflow=6.51 cfs 2.992 af Peak Elev=348.48' Storage=121 cf Inflow=0.75 cfs 0.035 afPond 170P: Infiltration Trench63 Discarded=0.06 cfs 0.025 af Primary=0.68 cfs 0.010 af Outflow=0.74 cfs 0.035 af Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Peak Elev=335.63' Storage=85 cf Inflow=0.43 cfs 0.020 afPond 171P: Infiltration Trench65 Discarded=0.04 cfs 0.016 af Primary=0.38 cfs 0.005 af Outflow=0.43 cfs 0.020 af Peak Elev=329.27' Storage=109 cf Inflow=0.75 cfs 0.035 afPond 172P: Infiltration Trench67 Discarded=0.06 cfs 0.025 af Primary=0.90 cfs 0.010 af Outflow=0.96 cfs 0.035 af Peak Elev=341.91' Storage=62 cf Inflow=0.48 cfs 0.023 afPond 173P: Infiltration Trench65A Discarded=0.04 cfs 0.016 af Primary=0.44 cfs 0.007 af Outflow=0.48 cfs 0.023 af Peak Elev=328.58' Storage=12,302 cf Inflow=9.46 cfs 0.381 afPond 174P: GravelWet1 Outflow=0.39 cfs 0.381 af Peak Elev=333.54' Storage=37,609 cf Inflow=25.28 cfs 1.153 afPond 175P: GravelWet2 Outflow=0.95 cfs 1.153 af Inflow=1.30 cfs 1.534 afLink 176L: Study2 Primary=1.30 cfs 1.534 af Inflow=1.30 cfs 1.534 afLink 177L: SN4 Primary=1.30 cfs 1.534 af Total Runoff Area = 33.820 ac Runoff Volume = 4.609 af Average Runoff Depth = 1.64" Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 155S: SWMA Runoff = 49.02 cfs @ 11.98 hrs, Volume= 2.630 af, Depth= 1.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 155S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)50 45 40 35 30 25 20 15 10 5 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=20.360 ac Runoff Volume=2.630 af Runoff Depth=1.55" Flow Length=1,465' Tc=6.8 min CN=74 49.02 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 156S: GCA1 Runoff = 3.90 cfs @ 11.96 hrs, Volume= 0.183 af, Depth= 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 156S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)4 3 2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=1.940 ac Runoff Volume=0.183 af Runoff Depth=1.13" Flow Length=168' Tc=4.5 min CN=67 3.90 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 157S: GCA2 Runoff = 1.36 cfs @ 11.95 hrs, Volume= 0.068 af, Depth= 0.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 157S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=1.200 ac Runoff Volume=0.068 af Runoff Depth=0.68" Flow Length=138' Tc=4.5 min CN=51 1.36 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 158S: GCA3 Runoff = 2.35 cfs @ 11.91 hrs, Volume= 0.111 af, Depth= 2.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 158S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.650 ac Runoff Volume=0.111 af Runoff Depth=2.04" Tc=1.0 min CN=79 2.35 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 159S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 2.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 159S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.170 ac Runoff Volume=0.035 af Runoff Depth=2.49" Tc=1.0 min CN=88 0.75 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 160S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Depth= 2.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 160S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.100 ac Runoff Volume=0.020 af Runoff Depth=2.41" Tc=1.0 min CN=86 0.43 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 161S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 2.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 161S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.170 ac Runoff Volume=0.035 af Runoff Depth=2.49" Tc=1.0 min CN=88 0.75 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 162S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.48 cfs @ 11.91 hrs, Volume= 0.023 af, Depth= 2.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 162S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.110 ac Runoff Volume=0.023 af Runoff Depth=2.47" Tc=1.0 min CN=87 0.48 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 179S: SWMC Runoff = 25.28 cfs @ 11.96 hrs, Volume= 1.153 af, Depth= 1.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description * 7.060 87 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.9 Direct Entry, Workbook-Lag Subcatchment 179S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=7.060 ac Runoff Volume=1.153 af Runoff Depth=1.96" Tc=4.9 min CN=87 25.28 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 180S: SWMB Runoff = 7.69 cfs @ 11.96 hrs, Volume= 0.351 af, Depth= 2.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description * 2.060 88 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.7 Direct Entry, Workbook- Lag Subcatchment 180S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)8 7 6 5 4 3 2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=2.060 ac Runoff Volume=0.351 af Runoff Depth=2.04" Tc=4.7 min CN=88 7.69 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 165R: GC-A1 Inflow Area = 1.940 ac, Inflow Depth = 1.13" for 10 Year event Inflow = 3.90 cfs @ 11.96 hrs, Volume= 0.183 af Outflow = 2.64 cfs @ 12.18 hrs, Volume= 0.183 af, Atten= 32%, Lag= 13.7 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.73 fps, Min. Travel Time= 10.1 min Avg. Velocity = 0.13 fps, Avg. Travel Time= 54.6 min Peak Storage= 1,596 cf @ 12.02 hrs Average Depth at Peak Storage= 0.55' Bank-Full Depth= 1.08' Flow Area= 8.9 sf, Capacity= 9.42 cfs 5.00' x 1.08' deep channel, n= 0.120 Side Slope Z-value= 3.0 '/' Top Width= 11.48' Length= 440.0' Slope= 0.0107 '/' Inlet Invert= 361.70', Outlet Invert= 357.00' ‡ Reach 165R: GC-A1 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)4 3 2 1 0 Inflow Area=1.940 ac Avg. Flow Depth=0.55' Max Vel=0.73 fps n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs 3.90 cfs 2.64 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 18HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 166R: GC-A2 Inflow Area = 1.200 ac, Inflow Depth = 0.68" for 10 Year event Inflow = 1.36 cfs @ 11.95 hrs, Volume= 0.068 af Outflow = 1.13 cfs @ 12.09 hrs, Volume= 0.068 af, Atten= 17%, Lag= 8.3 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.72 fps, Min. Travel Time= 5.8 min Avg. Velocity = 0.15 fps, Avg. Travel Time= 27.7 min Peak Storage= 393 cf @ 11.99 hrs Average Depth at Peak Storage= 0.32' Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 9.60 cfs 4.00' x 1.00' deep channel, n= 0.150 Side Slope Z-value= 3.0 '/' Top Width= 10.00' Length= 252.0' Slope= 0.0321 '/' Inlet Invert= 365.10', Outlet Invert= 357.00' ‡ Reach 166R: GC-A2 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=1.200 ac Avg. Flow Depth=0.32' Max Vel=0.72 fps n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs 1.36 cfs 1.13 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 19HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 167R: GC-A3 Inflow Area = 0.650 ac, Inflow Depth = 2.04" for 10 Year event Inflow = 2.35 cfs @ 11.91 hrs, Volume= 0.111 af Outflow = 1.40 cfs @ 12.18 hrs, Volume= 0.111 af, Atten= 41%, Lag= 16.5 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.65 fps, Min. Travel Time= 13.3 min Avg. Velocity = 0.13 fps, Avg. Travel Time= 64.6 min Peak Storage= 1,115 cf @ 11.96 hrs Average Depth at Peak Storage= 0.48' Bank-Full Depth= 1.00' Flow Area= 6.0 sf, Capacity= 5.84 cfs 3.00' x 1.00' deep channel, n= 0.125 Side Slope Z-value= 3.0 '/' Top Width= 9.00' Length= 520.0' Slope= 0.0121 '/' Inlet Invert= 342.67', Outlet Invert= 336.40' ‡ Reach 167R: GC-A3 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Inflow Area=0.650 ac Avg. Flow Depth=0.48' Max Vel=0.65 fps n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs 2.35 cfs 1.40 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 20HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 168P: Pond A Inflow Area = 24.150 ac, Inflow Depth = 1.49" for 10 Year event Inflow = 50.78 cfs @ 11.98 hrs, Volume= 2.992 af Outflow = 7.70 cfs @ 12.37 hrs, Volume= 2.992 af, Atten= 85%, Lag= 23.0 min Primary = 7.70 cfs @ 12.37 hrs, Volume= 2.992 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 331.25' Surf.Area= 13,348 sf Storage= 23,564 cf Peak Elev= 334.50' @ 12.37 hrs Surf.Area= 19,712 sf Storage= 76,708 cf (53,144 cf above start) Plug-Flow detention time= 256.7 min calculated for 2.451 af (82% of inflow) Center-of-Mass det. time= 119.0 min ( 905.3 - 786.3 ) Volume Invert Avail.Storage Storage Description #1 327.25' 120,624 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 327.25 37 0 0 327.75 2,014 513 513 328.00 2,516 566 1,079 329.00 4,793 3,655 4,734 330.00 6,677 5,735 10,469 331.00 12,941 9,809 20,278 332.00 14,567 13,754 34,032 333.00 16,466 15,517 49,548 334.00 18,587 17,527 67,075 335.00 20,824 19,706 86,780 336.00 23,135 21,980 108,760 336.50 24,321 11,864 120,624 Device Routing Invert Outlet Devices #1 Primary 331.15'15.0" Round Culvert L= 20.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 331.15' / 331.00' S= 0.0075 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 331.25'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.75'48.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 #4 Primary 335.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=7.70 cfs @ 12.37 hrs HW=334.50' (Free Discharge) 1=Culvert (Inlet Controls 7.70 cfs @ 6.28 fps) 2=Orifice/Grate (Passes < 6.27 cfs potential flow) 3=Orifice/Grate (Passes < 21.41 cfs potential flow) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 21HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 168P: Pond A Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=24.150 ac Peak Elev=334.50' Storage=76,708 cf 50.78 cfs 7.70 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 22HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 169P: Infiltration A Inflow Area = 24.150 ac, Inflow Depth = 1.49" for 10 Year event Inflow = 7.70 cfs @ 12.37 hrs, Volume= 2.992 af Outflow = 6.51 cfs @ 12.01 hrs, Volume= 2.992 af, Atten= 16%, Lag= 0.0 min Discarded = 6.51 cfs @ 12.01 hrs, Volume= 2.992 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 331.60' @ 13.54 hrs Surf.Area= 7,823 sf Storage= 4,469 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 4.0 min ( 909.3 - 905.3 ) Volume Invert Avail.Storage Storage Description #1 331.00' 27,230 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,013 0 0 332.00 8,357 7,685 7,685 333.00 9,758 9,058 16,743 334.00 11,216 10,487 27,230 Device Routing Invert Outlet Devices #1 Discarded 331.00'40.000 in/hr Exfiltration over Surface area below 331.01' #2 Primary 331.75'6.0" Vert. Orifice/Grate C= 0.600 #3 Primary 333.25'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Discarded OutFlow Max=6.51 cfs @ 12.01 hrs HW=331.03' (Free Discharge) 1=Exfiltration (Exfiltration Controls 6.51 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=331.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 23HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 169P: Infiltration A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=24.150 ac Peak Elev=331.60' Storage=4,469 cf 7.70 cfs 6.51 cfs6.51 cfs 0.00 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 24HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 170P: Infiltration Trench63 Inflow Area = 0.170 ac, Inflow Depth = 2.49" for 10 Year event Inflow = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af Outflow = 0.74 cfs @ 11.91 hrs, Volume= 0.035 af, Atten= 1%, Lag= 0.2 min Discarded = 0.06 cfs @ 11.53 hrs, Volume= 0.025 af Primary = 0.68 cfs @ 11.91 hrs, Volume= 0.010 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 348.48' @ 11.91 hrs Surf.Area= 102 sf Storage= 121 cf Plug-Flow detention time= 6.0 min calculated for 0.035 af (100% of inflow) Center-of-Mass det. time= 6.0 min ( 753.6 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 352.80' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 346.18' 72 cf 3.25'W x 31.50'L x 2.42'H Field A 248 cf Overall - 67 cf Embedded = 181 cf x 40.0% Voids #3A 346.51' 54 cf ADS N-12 18 x 2 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 156 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 352.80 20 0 0 353.30 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 346.18'25.000 in/hr Exfiltration over Surface area below 346.19' #2 Primary 348.09'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.53 hrs HW=346.25' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.68 cfs @ 11.91 hrs HW=348.47' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.68 cfs @ 2.11 fps) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 25HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 170P: Infiltration Trench63 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 2 Chambers/Row x 20.00' Long -10.00' Row Adjustment = 30.00' Row Length +9.0" End Stone x 2 = 31.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 2 Chambers x 36.0 cf -10.00' Row Adjustment x 1.80 sf x 1 Rows = 54.0 cf Chamber Storage 2 Chambers x 44.5 cf -10.00' Row Adjustment x 2.23 sf x 1 Rows = 66.8 cf Displacement 247.5 cf Field - 66.8 cf Chambers = 180.7 cf Stone x 40.0% Voids = 72.3 cf Stone Storage Chamber Storage + Stone Storage = 126.3 cf = 0.003 af Overall Storage Efficiency = 51.0% 2 Chambers 9.2 cy Field 6.7 cy Stone Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 26HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 170P: Infiltration Trench63 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.170 ac Peak Elev=348.48' Storage=121 cf 0.75 cfs0.74 cfs 0.06 cfs 0.68 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 27HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 171P: Infiltration Trench65 Inflow Area = 0.100 ac, Inflow Depth = 2.41" for 10 Year event Inflow = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af Outflow = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Atten= 1%, Lag= 0.2 min Discarded = 0.04 cfs @ 11.56 hrs, Volume= 0.016 af Primary = 0.38 cfs @ 11.91 hrs, Volume= 0.005 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Peak Elev= 335.63' @ 11.91 hrs Surf.Area= 76 sf Storage= 85 cf Plug-Flow detention time= 6.1 min calculated for 0.020 af (100% of inflow) Center-of-Mass det. time= 6.1 min ( 753.7 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 339.60' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 333.52' 54 cf 3.25'W x 23.50'L x 2.42'H Field A 185 cf Overall - 49 cf Embedded = 136 cf x 40.0% Voids #3A 333.85' 40 cf ADS N-12 18 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 124 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 339.60 20 0 0 340.10 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 333.52'25.000 in/hr Exfiltration over Surface area below 333.53' #2 Primary 335.35'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.56 hrs HW=333.60' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.38 cfs @ 11.91 hrs HW=335.63' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.38 cfs @ 1.81 fps) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 28HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 171P: Infiltration Trench65 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +9.0" End Stone x 2 = 23.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 1 Chambers x 36.0 cf +2.00' Row Adjustment x 1.80 sf x 1 Rows = 39.6 cf Chamber Storage 1 Chambers x 44.5 cf +2.00' Row Adjustment x 2.23 sf x 1 Rows = 49.0 cf Displacement 184.6 cf Field - 49.0 cf Chambers = 135.7 cf Stone x 40.0% Voids = 54.3 cf Stone Storage Chamber Storage + Stone Storage = 93.9 cf = 0.002 af Overall Storage Efficiency = 50.8% 1 Chambers 6.8 cy Field 5.0 cy Stone Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 29HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 171P: Infiltration Trench65 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.100 ac Peak Elev=335.63' Storage=85 cf 0.43 cfs0.43 cfs 0.04 cfs 0.38 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 30HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 172P: Infiltration Trench67 Inflow Area = 0.170 ac, Inflow Depth = 2.49" for 10 Year event Inflow = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af Outflow = 0.96 cfs @ 11.91 hrs, Volume= 0.035 af, Atten= 0%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.55 hrs, Volume= 0.025 af Primary = 0.90 cfs @ 11.91 hrs, Volume= 0.010 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 329.27' @ 11.91 hrs Surf.Area= 103 sf Storage= 109 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 7.3 min ( 754.9 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 333.27' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 27.52' 67 cf 2.83'W x 36.33'L x 2.17'H Field A 223 cf Overall - 56 cf Embedded = 167 cf x 40.0% Voids #3A 27.85' 42 cf ADS N-12 15 x 2 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 139 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 333.27 20 0 0 333.77 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 27.52'25.000 in/hr Exfiltration over Surface area below 327.53' #2 Primary 329.02'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.55 hrs HW=27.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.30 cfs @ 11.91 hrs HW=329.27' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.30 cfs @ 1.70 fps) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 31HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 172P: Infiltration Trench67 - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 2 Chambers/Row x 20.00' Long -5.00' Row Adjustment = 35.00' Row Length +8.0" End Stone x 2 = 36.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 2 Chambers x 24.0 cf -5.00' Row Adjustment x 1.20 sf x 1 Rows = 42.0 cf Chamber Storage 2 Chambers x 31.9 cf -5.00' Row Adjustment x 1.60 sf x 1 Rows = 55.9 cf Displacement 222.9 cf Field - 55.9 cf Chambers = 167.1 cf Stone x 40.0% Voids = 66.8 cf Stone Storage Chamber Storage + Stone Storage = 108.8 cf = 0.002 af Overall Storage Efficiency = 48.8% 2 Chambers 8.3 cy Field 6.2 cy Stone Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 32HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 172P: Infiltration Trench67 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=0.170 ac Peak Elev=329.27' Storage=109 cf 0.75 cfs 0.96 cfs 0.06 cfs 0.90 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 33HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 173P: Infiltration Trench65A Inflow Area = 0.110 ac, Inflow Depth = 2.47" for 10 Year event Inflow = 0.48 cfs @ 11.91 hrs, Volume= 0.023 af Outflow = 0.48 cfs @ 11.91 hrs, Volume= 0.023 af, Atten= 1%, Lag= 0.1 min Discarded = 0.04 cfs @ 11.53 hrs, Volume= 0.016 af Primary = 0.44 cfs @ 11.91 hrs, Volume= 0.007 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 341.91' @ 11.91 hrs Surf.Area= 66 sf Storage= 62 cf Plug-Flow detention time= 4.5 min calculated for 0.023 af (100% of inflow) Center-of-Mass det. time= 4.6 min ( 752.2 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 345.68' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 340.02' 43 cf 2.83'W x 23.33'L x 2.17'H Field A 143 cf Overall - 35 cf Embedded = 108 cf x 40.0% Voids #3A 340.35' 26 cf ADS N-12 15 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 100 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 345.68 20 0 0 346.18 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 340.02'25.000 in/hr Exfiltration over Surface area below 340.03' #2 Primary 341.60'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.53 hrs HW=340.08' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.43 cfs @ 11.91 hrs HW=341.90' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.43 cfs @ 1.88 fps) Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 34HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 173P: Infiltration Trench65A - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +8.0" End Stone x 2 = 23.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 1 Chambers x 24.0 cf +2.00' Row Adjustment x 1.20 sf x 1 Rows = 26.4 cf Chamber Storage 1 Chambers x 31.9 cf +2.00' Row Adjustment x 1.60 sf x 1 Rows = 35.1 cf Displacement 143.2 cf Field - 35.1 cf Chambers = 108.1 cf Stone x 40.0% Voids = 43.2 cf Stone Storage Chamber Storage + Stone Storage = 69.6 cf = 0.002 af Overall Storage Efficiency = 48.6% 1 Chambers 5.3 cy Field 4.0 cy Stone Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 35HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 173P: Infiltration Trench65A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.110 ac Peak Elev=341.91' Storage=62 cf 0.48 cfs0.48 cfs 0.04 cfs 0.44 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 36HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 174P: GravelWet1 Inflow Area = 2.610 ac, Inflow Depth = 1.75" for 10 Year event Inflow = 9.46 cfs @ 11.95 hrs, Volume= 0.381 af Outflow = 0.39 cfs @ 12.93 hrs, Volume= 0.381 af, Atten= 96%, Lag= 58.8 min Primary = 0.39 cfs @ 12.93 hrs, Volume= 0.381 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 326.17' Surf.Area= 4,400 sf Storage= 2,125 cf Peak Elev= 328.58' @ 12.93 hrs Surf.Area= 10,731 sf Storage= 12,302 cf (10,177 cf above start) Plug-Flow detention time= 1,092.9 min calculated for 0.333 af (87% of inflow) Center-of-Mass det. time= 891.5 min ( 1,693.8 - 802.3 ) Volume Invert Avail.Storage Storage Description #1 323.50' 2,050 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,126 cf Overall x 40.0% Voids #2 325.83' 147 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,474 cf Overall x 10.0% Voids #3 326.50' 20,418 cf Custom Stage Data (Prismatic) Listed below (Recalc) 22,616 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 323.50 2,200 0 0 325.83 2,200 5,126 5,126 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 325.83 2,200 0 0 326.50 2,200 1,474 1,474 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 326.50 2,200 0 0 327.00 4,413 1,653 1,653 328.00 5,610 5,012 6,665 329.00 6,862 6,236 12,901 330.00 8,172 7,517 20,418 Device Routing Invert Outlet Devices #1 Primary 326.17'18.0" Round Culvert L= 75.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 326.17' / 325.80' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 326.17'1.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 327.30'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 328.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 37HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Primary OutFlow Max=0.39 cfs @ 12.93 hrs HW=328.58' (Free Discharge) 1=Culvert (Passes 0.39 cfs of 8.64 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.09 cfs @ 7.37 fps) 3=Orifice/Grate (Orifice Controls 0.03 cfs @ 5.35 fps) 4=Orifice/Grate (Orifice Controls 0.27 cfs @ 0.89 fps) Pond 174P: GravelWet1 Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.610 ac Peak Elev=328.58' Storage=12,302 cf 9.46 cfs 0.39 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 38HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 175P: GravelWet2 Inflow Area = 7.060 ac, Inflow Depth = 1.96" for 10 Year event Inflow = 25.28 cfs @ 11.96 hrs, Volume= 1.153 af Outflow = 0.95 cfs @ 13.51 hrs, Volume= 1.153 af, Atten= 96%, Lag= 93.1 min Primary = 0.95 cfs @ 13.51 hrs, Volume= 1.153 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 330.67' Surf.Area= 15,488 sf Storage= 7,481 cf Peak Elev= 333.54' @ 13.51 hrs Surf.Area= 30,197 sf Storage= 37,609 cf (30,128 cf above start) Plug-Flow detention time= 1,055.3 min calculated for 0.981 af (85% of inflow) Center-of-Mass det. time= 831.9 min ( 1,646.0 - 814.1 ) Volume Invert Avail.Storage Storage Description #1 328.00' 7,217 cf Custom Stage Data (Prismatic) Listed below (Recalc) 18,044 cf Overall x 40.0% Voids #2 330.33' 519 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,188 cf Overall x 10.0% Voids #3 331.00' 44,909 cf Custom Stage Data (Prismatic) Listed below (Recalc) 52,645 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 328.00 7,744 0 0 330.33 7,744 18,044 18,044 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 330.33 7,744 0 0 331.00 7,744 5,188 5,188 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,744 0 0 332.00 11,537 9,641 9,641 333.00 13,558 12,548 22,188 334.00 15,674 14,616 36,804 334.50 16,744 8,105 44,909 Device Routing Invert Outlet Devices #1 Primary 330.67'18.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 330.67' / 329.00' S= 0.1113 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 330.67'2.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.00'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 333.00'6.0" Vert. Orifice/Grate C= 0.600 #5 Device 1 333.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #6 Primary 333.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 39HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.94 cfs @ 13.51 hrs HW=333.54' (Free Discharge) 1=Culvert (Passes 0.94 cfs of 9.79 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.27 cfs @ 8.01 fps) 3=Orifice/Grate (Orifice Controls 0.03 cfs @ 5.90 fps) 4=Orifice/Grate (Orifice Controls 0.51 cfs @ 2.61 fps) 5=Orifice/Grate (Orifice Controls 0.12 cfs @ 0.67 fps) 6=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 175P: GravelWet2 InflowPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=7.060 ac Peak Elev=333.54' Storage=37,609 cf 25.28 cfs 0.95 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 40HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 176L: Study2 Inflow Area = 33.820 ac, Inflow Depth = 0.54" for 10 Year event Inflow = 1.30 cfs @ 13.39 hrs, Volume= 1.534 af Primary = 1.30 cfs @ 13.39 hrs, Volume= 1.534 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 176L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=33.820 ac 1.30 cfs1.30 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 41HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 177L: SN4 Inflow Area = 33.820 ac, Inflow Depth = 0.54" for 10 Year event Inflow = 1.30 cfs @ 13.39 hrs, Volume= 1.534 af Primary = 1.30 cfs @ 13.39 hrs, Volume= 1.534 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 177L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=33.820 ac 1.30 cfs1.30 cfs Qp10-No Routing 155S SWMA156S GCA1 157S GCA2 158S GCA3 159S CB63/64 160S CB65/66 161S CB66/67 162S CB65A/66A 179S SWMC 180S SWMB 176L Study2 177L SN4 Routing Diagram for Hillside2020-post-no-routingPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model - No Routing Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (155S, 156S, 157S, 158S, 159S, 160S, 161S, 162S) 0.370 61 >75% Grass cover, Good, HSG B (155S) 3.520 74 >75% Grass cover, Good, HSG C (155S) 4.160 80 >75% Grass cover, Good, HSG D (155S, 156S, 157S) 4.670 98 Paved parking, HSG A (155S, 159S, 160S, 161S, 162S) 3.810 98 Roofs, HSG A (155S, 156S, 157S, 158S) 0.200 98 Water Surface, 0% imp, HSG A (155S) 0.730 30 Woods, Good, HSG A (155S, 156S, 157S) 0.910 77 Woods, Good, HSG D (155S, 156S, 157S) 7.060 87 Workbook (179S) 2.060 88 Workbook (180S) 33.820 77 TOTAL AREA Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=1.55"Subcatchment 155S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=49.02 cfs 2.630 af Runoff Area=1.940 ac Runoff Depth=1.13"Subcatchment 156S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=3.90 cfs 0.183 af Runoff Area=1.200 ac Runoff Depth=0.68"Subcatchment 157S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=1.36 cfs 0.068 af Runoff Area=0.650 ac Runoff Depth=2.04"Subcatchment 158S: GCA3 Tc=1.0 min CN=79 Runoff=2.35 cfs 0.111 af Runoff Area=0.170 ac Runoff Depth=2.49"Subcatchment 159S: CB63/64 Tc=1.0 min CN=88 Runoff=0.75 cfs 0.035 af Runoff Area=0.100 ac Runoff Depth=2.41"Subcatchment 160S: CB65/66 Tc=1.0 min CN=86 Runoff=0.43 cfs 0.020 af Runoff Area=0.170 ac Runoff Depth=2.49"Subcatchment 161S: CB66/67 Tc=1.0 min CN=88 Runoff=0.75 cfs 0.035 af Runoff Area=0.110 ac Runoff Depth=2.47"Subcatchment 162S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.48 cfs 0.023 af Runoff Area=7.060 ac Runoff Depth=1.96"Subcatchment 179S: SWMC Tc=4.9 min CN=87 Runoff=25.28 cfs 1.153 af Runoff Area=2.060 ac Runoff Depth=2.04"Subcatchment 180S: SWMB Tc=4.7 min CN=88 Runoff=7.69 cfs 0.351 af Inflow=88.99 cfs 4.609 afLink 176L: Study2 Primary=88.99 cfs 4.609 af Inflow=88.99 cfs 4.609 afLink 177L: SN4 Primary=88.99 cfs 4.609 af Total Runoff Area = 33.820 ac Runoff Volume = 4.609 af Average Runoff Depth = 1.64" Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 155S: SWMA Runoff = 49.02 cfs @ 11.98 hrs, Volume= 2.630 af, Depth= 1.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 155S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)50 45 40 35 30 25 20 15 10 5 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=20.360 ac Runoff Volume=2.630 af Runoff Depth=1.55" Flow Length=1,465' Tc=6.8 min CN=74 49.02 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 156S: GCA1 Runoff = 3.90 cfs @ 11.96 hrs, Volume= 0.183 af, Depth= 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 156S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)4 3 2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=1.940 ac Runoff Volume=0.183 af Runoff Depth=1.13" Flow Length=168' Tc=4.5 min CN=67 3.90 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 157S: GCA2 Runoff = 1.36 cfs @ 11.95 hrs, Volume= 0.068 af, Depth= 0.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 157S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=1.200 ac Runoff Volume=0.068 af Runoff Depth=0.68" Flow Length=138' Tc=4.5 min CN=51 1.36 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 158S: GCA3 Runoff = 2.35 cfs @ 11.91 hrs, Volume= 0.111 af, Depth= 2.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 158S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.650 ac Runoff Volume=0.111 af Runoff Depth=2.04" Tc=1.0 min CN=79 2.35 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 159S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 2.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 159S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.170 ac Runoff Volume=0.035 af Runoff Depth=2.49" Tc=1.0 min CN=88 0.75 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 160S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.43 cfs @ 11.91 hrs, Volume= 0.020 af, Depth= 2.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 160S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.100 ac Runoff Volume=0.020 af Runoff Depth=2.41" Tc=1.0 min CN=86 0.43 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 161S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 0.75 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 2.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 161S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.170 ac Runoff Volume=0.035 af Runoff Depth=2.49" Tc=1.0 min CN=88 0.75 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 162S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.48 cfs @ 11.91 hrs, Volume= 0.023 af, Depth= 2.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 162S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=0.110 ac Runoff Volume=0.023 af Runoff Depth=2.47" Tc=1.0 min CN=87 0.48 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 179S: SWMC Runoff = 25.28 cfs @ 11.96 hrs, Volume= 1.153 af, Depth= 1.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description * 7.060 87 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.9 Direct Entry, Workbook-Lag Subcatchment 179S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=7.060 ac Runoff Volume=1.153 af Runoff Depth=1.96" Tc=4.9 min CN=87 25.28 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 180S: SWMB Runoff = 7.69 cfs @ 11.96 hrs, Volume= 0.351 af, Depth= 2.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Year Rainfall=3.25" Area (ac) CN Description * 2.060 88 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.7 Direct Entry, Workbook- Lag Subcatchment 180S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)8 7 6 5 4 3 2 1 0 Type II 24-hr 10 Year Rainfall=3.25" Runoff Area=2.060 ac Runoff Volume=0.351 af Runoff Depth=2.04" Tc=4.7 min CN=88 7.69 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 176L: Study2 Inflow Area = 33.820 ac, Inflow Depth = 1.64" for 10 Year event Inflow = 88.99 cfs @ 11.97 hrs, Volume= 4.609 af Primary = 88.99 cfs @ 11.97 hrs, Volume= 4.609 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 176L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=33.820 ac 88.99 cfs88.99 cfs Type II 24-hr 10 Year Rainfall=3.25"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 177L: SN4 Inflow Area = 33.820 ac, Inflow Depth = 1.64" for 10 Year event Inflow = 88.99 cfs @ 11.97 hrs, Volume= 4.609 af Primary = 88.99 cfs @ 11.97 hrs, Volume= 4.609 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 177L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=33.820 ac 88.99 cfs88.99 cfs Qp100 13S Pre2 14L SN4 Routing Diagram for Hillside2020-prePrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Apartments Pre Development Stormwater Model Qp10 & Qp100 Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 19.200 56 Workbook (13S) 19.200 56 TOTAL AREA Type II 24-hr 100 Year Rainfall=5.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=19.200 ac Runoff Depth=1.15"Subcatchment 13S: Pre2 Tc=24.4 min CN=56 Runoff=18.09 cfs 1.834 af Inflow=18.09 cfs 1.834 afLink 14L: SN4 Primary=18.09 cfs 1.834 af Total Runoff Area = 19.200 ac Runoff Volume = 1.834 af Average Runoff Depth = 1.15" Type II 24-hr 100 Year Rainfall=5.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 13S: Pre2 Area to 24" Culvert on Kennedy Drive east of Windridge Runoff = 18.09 cfs @ 12.21 hrs, Volume= 1.834 af, Depth= 1.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type II 24-hr 100 Year Rainfall=5.20" Area (ac) CN Description * 19.200 56 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 24.4 Direct Entry, Workbook-Lag Subcatchment 13S: Pre2 Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765Flow (cfs)20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 100 Year Rainfall=5.20" Runoff Area=19.200 ac Runoff Volume=1.834 af Runoff Depth=1.15" Tc=24.4 min CN=56 18.09 cfs Type II 24-hr 100 Year Rainfall=5.20"Hillside2020-pre Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 14L: SN4 Inflow Area = 19.200 ac, Inflow Depth = 1.15" for 100 Year event Inflow = 18.09 cfs @ 12.21 hrs, Volume= 1.834 af Primary = 18.09 cfs @ 12.21 hrs, Volume= 1.834 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Link 14L: SN4 Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086Flow (cfs)20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=19.200 ac 18.09 cfs18.09 cfs Qp100 Grass Channels, Pond A, Infiltration A Unchanged Infiltration Trenches Unchanged 181S SWMA182S GCA1 183S GCA2 184S GCA3 185S CB63/64 186S CB65/66 187S CB66/67 188S CB65A/66A 205S SWMB 206S SWMC 191R GC-A1 192R GC-A2 193R GC-A3 194P Pond A 195P Infiltration A 196P Infiltration Trench63 197P Infiltration Trench65 198P Infiltration Trench67 199P Infiltration Trench65A 200P GravelWet1 201P GravelWet2 202L Study2 203L SN4 Routing Diagram for Hillside2020-postPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (181S, 182S, 183S, 184S, 185S, 186S, 187S, 188S) 0.370 61 >75% Grass cover, Good, HSG B (181S) 3.520 74 >75% Grass cover, Good, HSG C (181S) 4.160 80 >75% Grass cover, Good, HSG D (181S, 182S, 183S) 4.670 98 Paved parking, HSG A (181S, 185S, 186S, 187S, 188S) 3.810 98 Roofs, HSG A (181S, 182S, 183S, 184S) 0.200 98 Water Surface, 0% imp, HSG A (181S) 0.730 30 Woods, Good, HSG A (181S, 182S, 183S) 0.910 77 Woods, Good, HSG D (181S, 182S, 183S) 2.060 85 Workbook (205S) 7.060 84 Workbook (206S) 33.820 76 TOTAL AREA Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=2.64"Subcatchment 181S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=82.01 cfs 4.474 af Runoff Area=1.940 ac Runoff Depth=2.06"Subcatchment 182S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=6.99 cfs 0.334 af Runoff Area=1.200 ac Runoff Depth=1.18"Subcatchment 183S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=2.23 cfs 0.118 af Runoff Area=0.650 ac Runoff Depth=3.18"Subcatchment 184S: GCA3 Tc=1.0 min CN=79 Runoff=3.53 cfs 0.172 af Runoff Area=0.170 ac Runoff Depth=3.83"Subcatchment 185S: CB63/64 Tc=1.0 min CN=88 Runoff=1.12 cfs 0.054 af Runoff Area=0.100 ac Runoff Depth=3.72"Subcatchment 186S: CB65/66 Tc=1.0 min CN=86 Runoff=0.64 cfs 0.031 af Runoff Area=0.170 ac Runoff Depth=3.83"Subcatchment 187S: CB66/67 Tc=1.0 min CN=88 Runoff=1.12 cfs 0.054 af Runoff Area=0.110 ac Runoff Depth=3.81"Subcatchment 188S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.72 cfs 0.035 af Runoff Area=2.060 ac Runoff Depth=3.23"Subcatchment 205S: SWMB Tc=5.3 min CN=85 Runoff=11.79 cfs 0.554 af Runoff Area=7.060 ac Runoff Depth=3.13"Subcatchment 206S: SWMC Tc=5.5 min CN=84 Runoff=39.17 cfs 1.844 af Avg. Flow Depth=0.79' Max Vel=0.89 fps Inflow=6.99 cfs 0.334 afReach 191R: GC-A1 n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs Outflow=5.14 cfs 0.334 af Avg. Flow Depth=0.42' Max Vel=0.86 fps Inflow=2.23 cfs 0.118 afReach 192R: GC-A2 n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs Outflow=1.91 cfs 0.118 af Avg. Flow Depth=0.61' Max Vel=0.75 fps Inflow=3.53 cfs 0.172 afReach 193R: GC-A3 n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs Outflow=2.22 cfs 0.172 af Peak Elev=336.19' Storage=113,311 cf Inflow=86.02 cfs 5.098 afPond 194P: Pond A Outflow=15.95 cfs 5.098 af Peak Elev=333.40' Storage=20,814 cf Inflow=15.95 cfs 5.098 afPond 195P: Infiltration A Discarded=6.51 cfs 4.630 af Primary=2.28 cfs 0.468 af Outflow=8.79 cfs 5.098 af Peak Elev=348.58' Storage=125 cf Inflow=1.12 cfs 0.054 afPond 196P: Infiltration Trench63 Discarded=0.06 cfs 0.036 af Primary=1.06 cfs 0.018 af Outflow=1.12 cfs 0.054 af Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Peak Elev=335.71' Storage=87 cf Inflow=0.64 cfs 0.031 afPond 197P: Infiltration Trench65 Discarded=0.04 cfs 0.022 af Primary=0.59 cfs 0.009 af Outflow=0.64 cfs 0.031 af Peak Elev=329.36' Storage=109 cf Inflow=1.12 cfs 0.054 afPond 198P: Infiltration Trench67 Discarded=0.06 cfs 0.036 af Primary=1.22 cfs 0.018 af Outflow=1.28 cfs 0.054 af Peak Elev=341.99' Storage=64 cf Inflow=0.72 cfs 0.035 afPond 199P: Infiltration Trench65A Discarded=0.04 cfs 0.023 af Primary=0.68 cfs 0.012 af Outflow=0.72 cfs 0.035 af Peak Elev=329.01' Storage=15,179 cf Inflow=14.23 cfs 0.613 afPond 200P: GravelWet1 Outflow=4.81 cfs 0.613 af Peak Elev=334.08' Storage=45,730 cf Inflow=39.17 cfs 1.844 afPond 201P: GravelWet2 Outflow=10.23 cfs 1.844 af Inflow=14.90 cfs 2.924 afLink 202L: Study2 Primary=14.90 cfs 2.924 af Inflow=14.90 cfs 2.924 afLink 203L: SN4 Primary=14.90 cfs 2.924 af Total Runoff Area = 33.820 ac Runoff Volume = 7.670 af Average Runoff Depth = 2.72" Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 181S: SWMA Runoff = 82.01 cfs @ 11.98 hrs, Volume= 4.474 af, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 181S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=20.360 ac Runoff Volume=4.474 af Runoff Depth=2.64" Flow Length=1,465' Tc=6.8 min CN=74 82.01 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 182S: GCA1 Runoff = 6.99 cfs @ 11.95 hrs, Volume= 0.334 af, Depth= 2.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 182S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)7 6 5 4 3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=1.940 ac Runoff Volume=0.334 af Runoff Depth=2.06" Flow Length=168' Tc=4.5 min CN=67 6.99 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 183S: GCA2 Runoff = 2.23 cfs @ 11.95 hrs, Volume= 0.118 af, Depth= 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 183S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=1.200 ac Runoff Volume=0.118 af Runoff Depth=1.18" Flow Length=138' Tc=4.5 min CN=51 2.23 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 184S: GCA3 Runoff = 3.53 cfs @ 11.91 hrs, Volume= 0.172 af, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 184S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.650 ac Runoff Volume=0.172 af Runoff Depth=3.18" Tc=1.0 min CN=79 3.53 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 185S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af, Depth= 3.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 185S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.170 ac Runoff Volume=0.054 af Runoff Depth=3.83" Tc=1.0 min CN=88 1.12 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 186S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.64 cfs @ 11.91 hrs, Volume= 0.031 af, Depth= 3.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 186S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.100 ac Runoff Volume=0.031 af Runoff Depth=3.72" Tc=1.0 min CN=86 0.64 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 187S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af, Depth= 3.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 187S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.170 ac Runoff Volume=0.054 af Runoff Depth=3.83" Tc=1.0 min CN=88 1.12 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 188S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.72 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 3.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 188S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.110 ac Runoff Volume=0.035 af Runoff Depth=3.81" Tc=1.0 min CN=87 0.72 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 205S: SWMB Runoff = 11.79 cfs @ 11.96 hrs, Volume= 0.554 af, Depth= 3.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description * 2.060 85 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.3 Direct Entry, Workbook- Lag Subcatchment 205S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=2.060 ac Runoff Volume=0.554 af Runoff Depth=3.23" Tc=5.3 min CN=85 11.79 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 206S: SWMC Runoff = 39.17 cfs @ 11.97 hrs, Volume= 1.844 af, Depth= 3.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description * 7.060 84 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 Direct Entry, Workbook-Lag Subcatchment 206S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=7.060 ac Runoff Volume=1.844 af Runoff Depth=3.13" Tc=5.5 min CN=84 39.17 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 191R: GC-A1 Inflow Area = 1.940 ac, Inflow Depth = 2.06" for 100 Year event Inflow = 6.99 cfs @ 11.95 hrs, Volume= 0.334 af Outflow = 5.14 cfs @ 12.14 hrs, Volume= 0.334 af, Atten= 26%, Lag= 11.4 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.89 fps, Min. Travel Time= 8.2 min Avg. Velocity = 0.16 fps, Avg. Travel Time= 45.8 min Peak Storage= 2,545 cf @ 12.01 hrs Average Depth at Peak Storage= 0.79' Bank-Full Depth= 1.08' Flow Area= 8.9 sf, Capacity= 9.42 cfs 5.00' x 1.08' deep channel, n= 0.120 Side Slope Z-value= 3.0 '/' Top Width= 11.48' Length= 440.0' Slope= 0.0107 '/' Inlet Invert= 361.70', Outlet Invert= 357.00' ‡ Reach 191R: GC-A1 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=1.940 ac Avg. Flow Depth=0.79' Max Vel=0.89 fps n=0.120 L=440.0' S=0.0107 '/' Capacity=9.42 cfs 6.99 cfs 5.14 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 18HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 192R: GC-A2 Inflow Area = 1.200 ac, Inflow Depth = 1.18" for 100 Year event Inflow = 2.23 cfs @ 11.95 hrs, Volume= 0.118 af Outflow = 1.91 cfs @ 12.07 hrs, Volume= 0.118 af, Atten= 14%, Lag= 7.1 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.86 fps, Min. Travel Time= 4.9 min Avg. Velocity = 0.18 fps, Avg. Travel Time= 23.0 min Peak Storage= 564 cf @ 11.99 hrs Average Depth at Peak Storage= 0.42' Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 9.60 cfs 4.00' x 1.00' deep channel, n= 0.150 Side Slope Z-value= 3.0 '/' Top Width= 10.00' Length= 252.0' Slope= 0.0321 '/' Inlet Invert= 365.10', Outlet Invert= 357.00' ‡ Reach 192R: GC-A2 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Inflow Area=1.200 ac Avg. Flow Depth=0.42' Max Vel=0.86 fps n=0.150 L=252.0' S=0.0321 '/' Capacity=9.60 cfs 2.23 cfs 1.91 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 19HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Reach 193R: GC-A3 Inflow Area = 0.650 ac, Inflow Depth = 3.18" for 100 Year event Inflow = 3.53 cfs @ 11.91 hrs, Volume= 0.172 af Outflow = 2.22 cfs @ 12.15 hrs, Volume= 0.172 af, Atten= 37%, Lag= 14.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Max. Velocity= 0.75 fps, Min. Travel Time= 11.6 min Avg. Velocity = 0.15 fps, Avg. Travel Time= 56.3 min Peak Storage= 1,549 cf @ 11.96 hrs Average Depth at Peak Storage= 0.61' Bank-Full Depth= 1.00' Flow Area= 6.0 sf, Capacity= 5.84 cfs 3.00' x 1.00' deep channel, n= 0.125 Side Slope Z-value= 3.0 '/' Top Width= 9.00' Length= 520.0' Slope= 0.0121 '/' Inlet Invert= 342.67', Outlet Invert= 336.40' ‡ Reach 193R: GC-A3 Inflow Outflow Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)3 2 1 0 Inflow Area=0.650 ac Avg. Flow Depth=0.61' Max Vel=0.75 fps n=0.125 L=520.0' S=0.0121 '/' Capacity=5.84 cfs 3.53 cfs 2.22 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 20HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 194P: Pond A Inflow Area = 24.150 ac, Inflow Depth = 2.53" for 100 Year event Inflow = 86.02 cfs @ 11.98 hrs, Volume= 5.098 af Outflow = 15.95 cfs @ 12.26 hrs, Volume= 5.098 af, Atten= 81%, Lag= 16.9 min Primary = 15.95 cfs @ 12.26 hrs, Volume= 5.098 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 331.25' Surf.Area= 13,348 sf Storage= 23,564 cf Peak Elev= 336.19' @ 12.26 hrs Surf.Area= 23,597 sf Storage= 113,311 cf (89,747 cf above start) Plug-Flow detention time= 213.9 min calculated for 4.557 af (89% of inflow) Center-of-Mass det. time= 117.4 min ( 900.8 - 783.4 ) Volume Invert Avail.Storage Storage Description #1 327.25' 120,624 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 327.25 37 0 0 327.75 2,014 513 513 328.00 2,516 566 1,079 329.00 4,793 3,655 4,734 330.00 6,677 5,735 10,469 331.00 12,941 9,809 20,278 332.00 14,567 13,754 34,032 333.00 16,466 15,517 49,548 334.00 18,587 17,527 67,075 335.00 20,824 19,706 86,780 336.00 23,135 21,980 108,760 336.50 24,321 11,864 120,624 Device Routing Invert Outlet Devices #1 Primary 331.15'15.0" Round Culvert L= 20.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 331.15' / 331.00' S= 0.0075 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 331.25'12.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.75'48.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 #4 Primary 335.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=15.91 cfs @ 12.26 hrs HW=336.19' (Free Discharge) 1=Culvert (Inlet Controls 9.81 cfs @ 7.99 fps) 2=Orifice/Grate (Passes < 7.97 cfs potential flow) 3=Orifice/Grate (Passes < 33.01 cfs potential flow) 4=Broad-Crested Rectangular Weir (Weir Controls 6.11 cfs @ 1.72 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 21HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 194P: Pond A Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=24.150 ac Peak Elev=336.19' Storage=113,311 cf 86.02 cfs 15.95 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 22HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 195P: Infiltration A Inflow Area = 24.150 ac, Inflow Depth = 2.53" for 100 Year event Inflow = 15.95 cfs @ 12.26 hrs, Volume= 5.098 af Outflow = 8.79 cfs @ 13.55 hrs, Volume= 5.098 af, Atten= 45%, Lag= 77.4 min Discarded = 6.51 cfs @ 11.90 hrs, Volume= 4.630 af Primary = 2.28 cfs @ 13.55 hrs, Volume= 0.468 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 333.40' @ 13.55 hrs Surf.Area= 10,348 sf Storage= 20,814 cf Plug-Flow detention time= 22.4 min calculated for 5.097 af (100% of inflow) Center-of-Mass det. time= 22.3 min ( 923.1 - 900.8 ) Volume Invert Avail.Storage Storage Description #1 331.00' 27,230 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,013 0 0 332.00 8,357 7,685 7,685 333.00 9,758 9,058 16,743 334.00 11,216 10,487 27,230 Device Routing Invert Outlet Devices #1 Discarded 331.00'40.000 in/hr Exfiltration over Surface area below 331.01' #2 Primary 331.75'6.0" Vert. Orifice/Grate C= 0.600 #3 Primary 333.25'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Discarded OutFlow Max=6.51 cfs @ 11.90 hrs HW=331.03' (Free Discharge) 1=Exfiltration (Exfiltration Controls 6.51 cfs) Primary OutFlow Max=2.28 cfs @ 13.55 hrs HW=333.40' (Free Discharge) 2=Orifice/Grate (Orifice Controls 1.12 cfs @ 5.71 fps) 3=Broad-Crested Rectangular Weir (Weir Controls 1.16 cfs @ 0.94 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 23HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 195P: Infiltration A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=24.150 ac Peak Elev=333.40' Storage=20,814 cf 15.95 cfs 8.79 cfs 6.51 cfs 2.28 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 24HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 196P: Infiltration Trench63 Inflow Area = 0.170 ac, Inflow Depth = 3.83" for 100 Year event Inflow = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af Outflow = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af, Atten= 1%, Lag= 0.1 min Discarded = 0.06 cfs @ 11.21 hrs, Volume= 0.036 af Primary = 1.06 cfs @ 11.91 hrs, Volume= 0.018 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 348.58' @ 11.91 hrs Surf.Area= 102 sf Storage= 125 cf Plug-Flow detention time= 5.6 min calculated for 0.054 af (100% of inflow) Center-of-Mass det. time= 5.6 min ( 747.6 - 742.0 ) Volume Invert Avail.Storage Storage Description #1 352.80' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 346.18' 72 cf 3.25'W x 31.50'L x 2.42'H Field A 248 cf Overall - 67 cf Embedded = 181 cf x 40.0% Voids #3A 346.51' 54 cf ADS N-12 18 x 2 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 156 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 352.80 20 0 0 353.30 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 346.18'25.000 in/hr Exfiltration over Surface area below 346.19' #2 Primary 348.09'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.21 hrs HW=346.25' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.05 cfs @ 11.91 hrs HW=348.58' (Free Discharge) 2=Orifice/Grate (Orifice Controls 1.05 cfs @ 2.37 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 25HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 196P: Infiltration Trench63 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= -10.00' x 1.80 sf x 1 rows 2 Chambers/Row x 20.00' Long -10.00' Row Adjustment = 30.00' Row Length +9.0" End Stone x 2 = 31.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 2 Chambers x 36.0 cf -10.00' Row Adjustment x 1.80 sf x 1 Rows = 54.0 cf Chamber Storage 2 Chambers x 44.5 cf -10.00' Row Adjustment x 2.23 sf x 1 Rows = 66.8 cf Displacement 247.5 cf Field - 66.8 cf Chambers = 180.7 cf Stone x 40.0% Voids = 72.3 cf Stone Storage Chamber Storage + Stone Storage = 126.3 cf = 0.003 af Overall Storage Efficiency = 51.0% 2 Chambers 9.2 cy Field 6.7 cy Stone Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 26HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 196P: Infiltration Trench63 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=0.170 ac Peak Elev=348.58' Storage=125 cf 1.12 cfs1.12 cfs 0.06 cfs 1.06 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 27HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 197P: Infiltration Trench65 Inflow Area = 0.100 ac, Inflow Depth = 3.72" for 100 Year event Inflow = 0.64 cfs @ 11.91 hrs, Volume= 0.031 af Outflow = 0.64 cfs @ 11.91 hrs, Volume= 0.031 af, Atten= 1%, Lag= 0.2 min Discarded = 0.04 cfs @ 11.48 hrs, Volume= 0.022 af Primary = 0.59 cfs @ 11.91 hrs, Volume= 0.009 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Peak Elev= 335.71' @ 11.91 hrs Surf.Area= 76 sf Storage= 87 cf Plug-Flow detention time= 5.4 min calculated for 0.031 af (100% of inflow) Center-of-Mass det. time= 5.4 min ( 747.8 - 742.4 ) Volume Invert Avail.Storage Storage Description #1 339.60' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 333.52' 54 cf 3.25'W x 23.50'L x 2.42'H Field A 185 cf Overall - 49 cf Embedded = 136 cf x 40.0% Voids #3A 333.85' 40 cf ADS N-12 18 Inside #2 Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 124 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 339.60 20 0 0 340.10 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 333.52'25.000 in/hr Exfiltration over Surface area below 333.53' #2 Primary 335.35'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.48 hrs HW=333.59' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.59 cfs @ 11.91 hrs HW=335.71' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.59 cfs @ 2.03 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 28HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 197P: Infiltration Trench65 - Chamber Wizard Field A Chamber Model = ADS N-12 18 (ADS N-12® Pipe) Inside= 18.2"W x 18.2"H => 1.80 sf x 20.00'L = 36.0 cf Outside= 21.0"W x 21.0"H => 2.23 sf x 20.00'L = 44.5 cf Row Length Adjustment= +2.00' x 1.80 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +9.0" End Stone x 2 = 23.50' Base Length 1 Rows x 21.0" Wide + 9.0" Side Stone x 2 = 3.25' Base Width 4.0" Base + 21.0" Chamber Height + 4.0" Cover = 2.42' Field Height 1 Chambers x 36.0 cf +2.00' Row Adjustment x 1.80 sf x 1 Rows = 39.6 cf Chamber Storage 1 Chambers x 44.5 cf +2.00' Row Adjustment x 2.23 sf x 1 Rows = 49.0 cf Displacement 184.6 cf Field - 49.0 cf Chambers = 135.7 cf Stone x 40.0% Voids = 54.3 cf Stone Storage Chamber Storage + Stone Storage = 93.9 cf = 0.002 af Overall Storage Efficiency = 50.8% 1 Chambers 6.8 cy Field 5.0 cy Stone Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 29HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 197P: Infiltration Trench65 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.100 ac Peak Elev=335.71' Storage=87 cf 0.64 cfs0.64 cfs 0.04 cfs 0.59 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 30HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 198P: Infiltration Trench67 Inflow Area = 0.170 ac, Inflow Depth = 3.83" for 100 Year event Inflow = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af Outflow = 1.28 cfs @ 11.91 hrs, Volume= 0.054 af, Atten= 0%, Lag= 0.0 min Discarded = 0.06 cfs @ 11.26 hrs, Volume= 0.036 af Primary = 1.22 cfs @ 11.91 hrs, Volume= 0.018 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 3 Peak Elev= 329.36' @ 11.91 hrs Surf.Area= 103 sf Storage= 109 cf Plug-Flow detention time= 8.2 min calculated for 0.054 af (100% of inflow) Center-of-Mass det. time= 7.0 min ( 749.0 - 742.0 ) Volume Invert Avail.Storage Storage Description #1 333.27' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 27.52' 67 cf 2.83'W x 36.33'L x 2.17'H Field A 223 cf Overall - 56 cf Embedded = 167 cf x 40.0% Voids #3A 27.85' 42 cf ADS N-12 15 x 2 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 139 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 333.27 20 0 0 333.77 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 27.52'25.000 in/hr Exfiltration over Surface area below 327.53' #2 Primary 329.02'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.06 cfs @ 11.26 hrs HW=27.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.53 cfs @ 11.91 hrs HW=329.36' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.53 cfs @ 1.98 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 31HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 198P: Infiltration Trench67 - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -5.00' x 1.20 sf x 1 rows 2 Chambers/Row x 20.00' Long -5.00' Row Adjustment = 35.00' Row Length +8.0" End Stone x 2 = 36.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 2 Chambers x 24.0 cf -5.00' Row Adjustment x 1.20 sf x 1 Rows = 42.0 cf Chamber Storage 2 Chambers x 31.9 cf -5.00' Row Adjustment x 1.60 sf x 1 Rows = 55.9 cf Displacement 222.9 cf Field - 55.9 cf Chambers = 167.1 cf Stone x 40.0% Voids = 66.8 cf Stone Storage Chamber Storage + Stone Storage = 108.8 cf = 0.002 af Overall Storage Efficiency = 48.8% 2 Chambers 8.3 cy Field 6.2 cy Stone Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 32HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 198P: Infiltration Trench67 Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Inflow Area=0.170 ac Peak Elev=329.36' Storage=109 cf 1.12 cfs 1.28 cfs 0.06 cfs 1.22 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 33HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 199P: Infiltration Trench65A Inflow Area = 0.110 ac, Inflow Depth = 3.81" for 100 Year event Inflow = 0.72 cfs @ 11.91 hrs, Volume= 0.035 af Outflow = 0.72 cfs @ 11.91 hrs, Volume= 0.035 af, Atten= 1%, Lag= 0.1 min Discarded = 0.04 cfs @ 11.21 hrs, Volume= 0.023 af Primary = 0.68 cfs @ 11.91 hrs, Volume= 0.012 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 341.99' @ 11.91 hrs Surf.Area= 66 sf Storage= 64 cf Plug-Flow detention time= 4.2 min calculated for 0.035 af (100% of inflow) Center-of-Mass det. time= 4.3 min ( 746.4 - 742.1 ) Volume Invert Avail.Storage Storage Description #1 345.68' 30 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2A 340.02' 43 cf 2.83'W x 23.33'L x 2.17'H Field A 143 cf Overall - 35 cf Embedded = 108 cf x 40.0% Voids #3A 340.35' 26 cf ADS N-12 15 Inside #2 Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 100 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 345.68 20 0 0 346.18 100 30 30 Device Routing Invert Outlet Devices #1 Discarded 340.02'25.000 in/hr Exfiltration over Surface area below 340.03' #2 Primary 341.60'15.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.04 cfs @ 11.21 hrs HW=340.08' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.68 cfs @ 11.91 hrs HW=341.98' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.68 cfs @ 2.11 fps) Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 34HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 199P: Infiltration Trench65A - Chamber Wizard Field A Chamber Model = ADS N-12 15 (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= +2.00' x 1.20 sf x 1 rows 1 Chambers/Row x 20.00' Long +2.00' Row Adjustment = 22.00' Row Length +8.0" End Stone x 2 = 23.33' Base Length 1 Rows x 18.0" Wide + 8.0" Side Stone x 2 = 2.83' Base Width 4.0" Base + 18.0" Chamber Height + 4.0" Cover = 2.17' Field Height 1 Chambers x 24.0 cf +2.00' Row Adjustment x 1.20 sf x 1 Rows = 26.4 cf Chamber Storage 1 Chambers x 31.9 cf +2.00' Row Adjustment x 1.60 sf x 1 Rows = 35.1 cf Displacement 143.2 cf Field - 35.1 cf Chambers = 108.1 cf Stone x 40.0% Voids = 43.2 cf Stone Storage Chamber Storage + Stone Storage = 69.6 cf = 0.002 af Overall Storage Efficiency = 48.6% 1 Chambers 5.3 cy Field 4.0 cy Stone Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 35HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Pond 199P: Infiltration Trench65A Inflow Outflow DiscardedPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.110 ac Peak Elev=341.99' Storage=64 cf 0.72 cfs0.72 cfs 0.04 cfs 0.68 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 36HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 200P: GravelWet1 Inflow Area = 2.610 ac, Inflow Depth = 2.82" for 100 Year event Inflow = 14.23 cfs @ 11.95 hrs, Volume= 0.613 af Outflow = 4.81 cfs @ 12.06 hrs, Volume= 0.613 af, Atten= 66%, Lag= 6.9 min Primary = 4.81 cfs @ 12.06 hrs, Volume= 0.613 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 326.17' Surf.Area= 4,400 sf Storage= 2,125 cf Peak Elev= 329.01' @ 12.06 hrs Surf.Area= 11,277 sf Storage= 15,179 cf (13,053 cf above start) Plug-Flow detention time= 710.3 min calculated for 0.564 af (92% of inflow) Center-of-Mass det. time= 605.3 min ( 1,401.6 - 796.3 ) Volume Invert Avail.Storage Storage Description #1 323.50' 2,050 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,126 cf Overall x 40.0% Voids #2 325.83' 147 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,474 cf Overall x 10.0% Voids #3 326.50' 20,418 cf Custom Stage Data (Prismatic) Listed below (Recalc) 22,616 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 323.50 2,200 0 0 325.83 2,200 5,126 5,126 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 325.83 2,200 0 0 326.50 2,200 1,474 1,474 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 326.50 2,200 0 0 327.00 4,413 1,653 1,653 328.00 5,610 5,012 6,665 329.00 6,862 6,236 12,901 330.00 8,172 7,517 20,418 Device Routing Invert Outlet Devices #1 Primary 326.17'18.0" Round Culvert L= 75.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 326.17' / 325.80' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 326.17'1.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 327.30'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 328.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 37HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Primary OutFlow Max=4.81 cfs @ 12.06 hrs HW=329.01' (Free Discharge) 1=Culvert (Passes 4.81 cfs of 9.71 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.10 cfs @ 8.03 fps) 3=Orifice/Grate (Orifice Controls 0.03 cfs @ 6.22 fps) 4=Orifice/Grate (Orifice Controls 4.68 cfs @ 2.34 fps) Pond 200P: GravelWet1 Inflow Primary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.610 ac Peak Elev=329.01' Storage=15,179 cf 14.23 cfs 4.81 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 38HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Pond 201P: GravelWet2 Inflow Area = 7.060 ac, Inflow Depth = 3.13" for 100 Year event Inflow = 39.17 cfs @ 11.97 hrs, Volume= 1.844 af Outflow = 10.23 cfs @ 12.10 hrs, Volume= 1.844 af, Atten= 74%, Lag= 7.8 min Primary = 10.23 cfs @ 12.10 hrs, Volume= 1.844 af Routing by Stor-Ind method, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Starting Elev= 330.67' Surf.Area= 15,488 sf Storage= 7,481 cf Peak Elev= 334.08' @ 12.10 hrs Surf.Area= 31,324 sf Storage= 45,730 cf (38,250 cf above start) Plug-Flow detention time= 686.4 min calculated for 1.672 af (91% of inflow) Center-of-Mass det. time= 568.1 min ( 1,376.4 - 808.2 ) Volume Invert Avail.Storage Storage Description #1 328.00' 7,217 cf Custom Stage Data (Prismatic) Listed below (Recalc) 18,044 cf Overall x 40.0% Voids #2 330.33' 519 cf Custom Stage Data (Prismatic) Listed below (Recalc) 5,188 cf Overall x 10.0% Voids #3 331.00' 44,909 cf Custom Stage Data (Prismatic) Listed below (Recalc) 52,645 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 328.00 7,744 0 0 330.33 7,744 18,044 18,044 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 330.33 7,744 0 0 331.00 7,744 5,188 5,188 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 331.00 7,744 0 0 332.00 11,537 9,641 9,641 333.00 13,558 12,548 22,188 334.00 15,674 14,616 36,804 334.50 16,744 8,105 44,909 Device Routing Invert Outlet Devices #1 Primary 330.67'18.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 330.67' / 329.00' S= 0.1113 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf #2 Device 1 330.67'2.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 332.00'1.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 333.00'6.0" Vert. Orifice/Grate C= 0.600 #5 Device 1 333.50'48.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #6 Primary 333.75'8.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 39HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=10.21 cfs @ 12.10 hrs HW=334.08' (Free Discharge) 1=Culvert (Passes 6.53 cfs of 10.95 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.30 cfs @ 8.75 fps) 3=Orifice/Grate (Orifice Controls 0.04 cfs @ 6.87 fps) 4=Orifice/Grate (Orifice Controls 0.86 cfs @ 4.37 fps) 5=Orifice/Grate (Orifice Controls 5.34 cfs @ 2.67 fps) 6=Broad-Crested Rectangular Weir (Weir Controls 3.68 cfs @ 1.41 fps) Pond 201P: GravelWet2 InflowPrimary Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=7.060 ac Peak Elev=334.08' Storage=45,730 cf 39.17 cfs 10.23 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 40HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 202L: Study2 Inflow Area = 33.820 ac, Inflow Depth = 1.04" for 100 Year event Inflow = 14.90 cfs @ 12.09 hrs, Volume= 2.924 af Primary = 14.90 cfs @ 12.09 hrs, Volume= 2.924 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 202L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=33.820 ac 14.90 cfs14.90 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 41HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 203L: SN4 Inflow Area = 33.820 ac, Inflow Depth = 1.04" for 100 Year event Inflow = 14.90 cfs @ 12.09 hrs, Volume= 2.924 af Primary = 14.90 cfs @ 12.09 hrs, Volume= 2.924 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 203L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=33.820 ac 14.90 cfs14.90 cfs Qp100-No Routing 181S SWMA182S GCA1 183S GCA2 184S GCA3 185S CB63/64 186S CB65/66 187S CB66/67 188S CB65A/66A 205S SWMB 206S SWMC 202L Study2 203L SN4 Routing Diagram for Hillside2020-post-no-routingPrepared by Krebs & Lansing Consulting Engineers, Inc., Printed 9/15/2021 HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcat Reach Pond Link Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 2HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Project Notes Hillside @ O'Brien Farm Eldredge Street, Kennedy Drive, Old Farm Road South Burlington, Vermont Post Development Stormwater Model - No Routing Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 3HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres) CN Description (subcatchment-numbers) 6.330 39 >75% Grass cover, Good, HSG A (181S, 182S, 183S, 184S, 185S, 186S, 187S, 188S) 0.370 61 >75% Grass cover, Good, HSG B (181S) 3.520 74 >75% Grass cover, Good, HSG C (181S) 4.160 80 >75% Grass cover, Good, HSG D (181S, 182S, 183S) 4.670 98 Paved parking, HSG A (181S, 185S, 186S, 187S, 188S) 3.810 98 Roofs, HSG A (181S, 182S, 183S, 184S) 0.200 98 Water Surface, 0% imp, HSG A (181S) 0.730 30 Woods, Good, HSG A (181S, 182S, 183S) 0.910 77 Woods, Good, HSG D (181S, 182S, 183S) 2.060 85 Workbook (205S) 7.060 84 Workbook (206S) 33.820 76 TOTAL AREA Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 4HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Time span=0.00-128.00 hrs, dt=0.01 hrs, 12801 points Runoff by SCS TR-20 method, UH=SCS, Weighted-Q Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=20.360 ac Runoff Depth=2.64"Subcatchment 181S: SWMA Flow Length=1,465' Tc=6.8 min CN=74 Runoff=82.01 cfs 4.474 af Runoff Area=1.940 ac Runoff Depth=2.06"Subcatchment 182S: GCA1 Flow Length=168' Tc=4.5 min CN=67 Runoff=6.99 cfs 0.334 af Runoff Area=1.200 ac Runoff Depth=1.18"Subcatchment 183S: GCA2 Flow Length=138' Tc=4.5 min CN=51 Runoff=2.23 cfs 0.118 af Runoff Area=0.650 ac Runoff Depth=3.18"Subcatchment 184S: GCA3 Tc=1.0 min CN=79 Runoff=3.53 cfs 0.172 af Runoff Area=0.170 ac Runoff Depth=3.83"Subcatchment 185S: CB63/64 Tc=1.0 min CN=88 Runoff=1.12 cfs 0.054 af Runoff Area=0.100 ac Runoff Depth=3.72"Subcatchment 186S: CB65/66 Tc=1.0 min CN=86 Runoff=0.64 cfs 0.031 af Runoff Area=0.170 ac Runoff Depth=3.83"Subcatchment 187S: CB66/67 Tc=1.0 min CN=88 Runoff=1.12 cfs 0.054 af Runoff Area=0.110 ac Runoff Depth=3.81"Subcatchment 188S: CB65A/66A Tc=1.0 min CN=87 Runoff=0.72 cfs 0.035 af Runoff Area=2.060 ac Runoff Depth=3.23"Subcatchment 205S: SWMB Tc=5.3 min CN=85 Runoff=11.79 cfs 0.554 af Runoff Area=7.060 ac Runoff Depth=3.13"Subcatchment 206S: SWMC Tc=5.5 min CN=84 Runoff=39.17 cfs 1.844 af Inflow=143.23 cfs 7.498 afLink 202L: Study2 Primary=143.23 cfs 7.498 af Inflow=143.23 cfs 7.498 afLink 203L: SN4 Primary=143.23 cfs 7.498 af Total Runoff Area = 33.820 ac Runoff Volume = 7.670 af Average Runoff Depth = 2.72" Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 5HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 181S: SWMA Runoff = 82.01 cfs @ 11.98 hrs, Volume= 4.474 af, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 2.880 98 Roofs, HSG A 4.220 98 Paved parking, HSG A 0.200 98 Water Surface, 0% imp, HSG A 5.250 39 >75% Grass cover, Good, HSG A 0.370 61 >75% Grass cover, Good, HSG B 3.520 74 >75% Grass cover, Good, HSG C 3.770 80 >75% Grass cover, Good, HSG D 0.020 30 Woods, Good, HSG A 0.130 77 Woods, Good, HSG D 20.360 74 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.2 20 0.0500 0.10 Sheet Flow, yard Grass: Dense n= 0.240 P2= 2.30" 1.8 220 0.0160 2.04 Shallow Concentrated Flow, swale Unpaved Kv= 16.1 fps 1.8 1,225 0.0450 11.17 13.70 Pipe Channel, Piped 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.013 Corrugated PE, smooth interior 6.8 1,465 Total Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 6HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Subcatchment 181S: SWMA Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=20.360 ac Runoff Volume=4.474 af Runoff Depth=2.64" Flow Length=1,465' Tc=6.8 min CN=74 82.01 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 7HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 182S: GCA1 Runoff = 6.99 cfs @ 11.95 hrs, Volume= 0.334 af, Depth= 2.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.290 98 Roofs, HSG A 0.320 30 Woods, Good, HSG A 0.680 77 Woods, Good, HSG D 0.320 39 >75% Grass cover, Good, HSG A 0.330 80 >75% Grass cover, Good, HSG D 1.940 67 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 140 0.2000 7.20 Shallow Concentrated Flow, shallow Unpaved Kv= 16.1 fps 4.5 168 Total Subcatchment 182S: GCA1 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)7 6 5 4 3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=1.940 ac Runoff Volume=0.334 af Runoff Depth=2.06" Flow Length=168' Tc=4.5 min CN=67 6.99 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 8HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 183S: GCA2 Runoff = 2.23 cfs @ 11.95 hrs, Volume= 0.118 af, Depth= 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.200 98 Roofs, HSG A 0.390 30 Woods, Good, HSG A 0.100 77 Woods, Good, HSG D 0.450 39 >75% Grass cover, Good, HSG A 0.060 80 >75% Grass cover, Good, HSG D 1.200 51 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 4.2 28 0.0500 0.11 Sheet Flow, sheet Grass: Dense n= 0.240 P2= 2.30" 0.3 110 0.1090 5.32 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 4.5 138 Total Subcatchment 183S: GCA2 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=1.200 ac Runoff Volume=0.118 af Runoff Depth=1.18" Flow Length=138' Tc=4.5 min CN=51 2.23 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 9HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 184S: GCA3 Runoff = 3.53 cfs @ 11.91 hrs, Volume= 0.172 af, Depth= 3.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.440 98 Roofs, HSG A 0.210 39 >75% Grass cover, Good, HSG A 0.650 79 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Subcatchment 184S: GCA3 Runoff Hydrograph Time (hours)12512011511010510095908580757065605550454035302520151050Flow (cfs)3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.650 ac Runoff Volume=0.172 af Runoff Depth=3.18" Tc=1.0 min CN=79 3.53 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 10HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 185S: CB63/64 Undeveloped area draining to Pond 2 Runoff = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af, Depth= 3.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 185S: CB63/64 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.170 ac Runoff Volume=0.054 af Runoff Depth=3.83" Tc=1.0 min CN=88 1.12 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 11HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 186S: CB65/66 Undeveloped area draining to Pond 2 Runoff = 0.64 cfs @ 11.91 hrs, Volume= 0.031 af, Depth= 3.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.080 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.100 86 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 186S: CB65/66 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.100 ac Runoff Volume=0.031 af Runoff Depth=3.72" Tc=1.0 min CN=86 0.64 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 12HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 187S: CB66/67 Undeveloped area draining to Pond 2 Runoff = 1.12 cfs @ 11.91 hrs, Volume= 0.054 af, Depth= 3.83" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.140 98 Paved parking, HSG A 0.030 39 >75% Grass cover, Good, HSG A 0.170 88 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 187S: CB66/67 Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.170 ac Runoff Volume=0.054 af Runoff Depth=3.83" Tc=1.0 min CN=88 1.12 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 13HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 188S: CB65A/66A Undeveloped area draining to Pond 2 Runoff = 0.72 cfs @ 11.91 hrs, Volume= 0.035 af, Depth= 3.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description 0.090 98 Paved parking, HSG A 0.020 39 >75% Grass cover, Good, HSG A 0.110 87 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Min. Subcatchment 188S: CB65A/66A Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=0.110 ac Runoff Volume=0.035 af Runoff Depth=3.81" Tc=1.0 min CN=87 0.72 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 14HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 205S: SWMB Runoff = 11.79 cfs @ 11.96 hrs, Volume= 0.554 af, Depth= 3.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description * 2.060 85 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.3 Direct Entry, Workbook- Lag Subcatchment 205S: SWMB Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=2.060 ac Runoff Volume=0.554 af Runoff Depth=3.23" Tc=5.3 min CN=85 11.79 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 15HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Subcatchment 206S: SWMC Runoff = 39.17 cfs @ 11.97 hrs, Volume= 1.844 af, Depth= 3.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Year Rainfall=4.85" Area (ac) CN Description * 7.060 84 Workbook Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 Direct Entry, Workbook-Lag Subcatchment 206S: SWMC Runoff Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type II 24-hr 100 Year Rainfall=4.85" Runoff Area=7.060 ac Runoff Volume=1.844 af Runoff Depth=3.13" Tc=5.5 min CN=84 39.17 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 16HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 202L: Study2 Inflow Area = 33.170 ac, Inflow Depth = 2.71" for 100 Year event Inflow = 143.23 cfs @ 11.97 hrs, Volume= 7.498 af Primary = 143.23 cfs @ 11.97 hrs, Volume= 7.498 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 202L: Study2 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 Inflow Area=33.170 ac 143.23 cfs143.23 cfs Type II 24-hr 100 Year Rainfall=4.85"Hillside2020-post-no-routing Printed 9/15/2021Prepared by Krebs & Lansing Consulting Engineers, Inc. Page 17HydroCAD® 10.00 s/n 06429 © 2013 HydroCAD Software Solutions LLC Summary for Link 203L: SN4 Inflow Area = 33.170 ac, Inflow Depth = 2.71" for 100 Year event Inflow = 143.23 cfs @ 11.97 hrs, Volume= 7.498 af Primary = 143.23 cfs @ 11.97 hrs, Volume= 7.498 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-128.00 hrs, dt= 0.01 hrs Link 203L: SN4 Inflow Primary Hydrograph Time (hours) 12512011511010510095908580757065605550454035302520151050Flow (cfs)160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 Inflow Area=33.170 ac 143.23 cfs143.23 cfs Version: 4/28/2017 Project Name: Response Attachment location 1 Plan Sheet C‐8 2 Plan Sheet C‐8 Attachment Location Plan Sheet C‐7 Plan Sheet C‐8 Response Attachment location 5 Plan Sheet C‐8 6 Plan Sheet C‐8 7 Plan Sheet C‐8 8 Plan Sheet C‐8 9 NA Response Attachment location Option 1: Leave undisturbed native vegetation and soil, and protect from compaction during construction. Option 2: Amend existing site topsoil or subsoil in place. Option 3: Remove and stockpile existing topsoil during grading. Option 4: Import topsoil mix, or other materials for mixing, including compost, of sufficient organic content and depth. Is compost or other materials used to amend soils specified to have a C:N ratio below 25:1? Is it specified that compost shall meet the definition of ʺcompostʺ or meet the contaminant standards in the Vermont Solid Waste Management Rules? If Exceptional Quality (EQ) biosolids are used as a soil amendment, do they comprise no more than 35% of the total volume of soil, and is it specifed that they be well mixed before or during application? Vegetation and Landscaping (3.3) Hillside @ OʹBrien Farm Does the site layout retain the duff layer and native topsoil in an undisturbed state to the maximum extent practicable? Is the organic matter content of the topsoil layer specified to be at least 4%? 4 Feasibility (3.1) Have all areas that will not be disturbed and areas exempt from the Standard, including the reason for the exemtion, been identified on a plan sheet? Have all areas of disturbance within the site that are subject to the Post‐ Construction Soil Depth and Quality Standard been identified on a plan sheet? This includes all disturbed areas on slopes ≤ 33% which are not covered by an impervious surface, part of a structural stormwater treatment practice, or engineered as structural fill once development is complete. Which of the following methods are utilized to meet soil quality requirements for this site? Post‐Construction Soil Depth and Quality Standard 3 Is the minimum topsoil depth specified as: 4 inches The depth of the 0 and A horizons on the NRCS Official Soil Series Description of the native mapped soils (provide documentation) Treatment (3.2) Yes No Yes No Yes No Yes No Yes No Yes No Yes No Page 1 of 2 10 Plan Sheet C‐8 11 Plan Sheet C‐8 12 Plan Sheet C‐8 13 Plan Sheet C‐8 14 Plan Sheet C‐8 15 Plan Sheet C‐8 Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has been provided within the application. Includes construction details and notes on the various methods the contractor may use to meet he Standard? Instructions to establish dense an vigorous vegeative cover over turf areas? Does the application include a site‐specific plan for soil management that: Includes a statement that soil depth and quality shall be established towards the end of construction, and once established, be protected from compaction? Identifies all areas on the site subject to the standard? Includes instructions for contractor verification of the Standard, including a sampling scheme that includes nine 8‐inch deep test holes per acre of area subject to the Standard? Instructions that test holes shall be excavated using only a shoven driven soley by the inspectorʹs weight and shall be at least 50 feet apart from each other? Yes No Yes No Yes No Yes No Yes No Yes No Page 2 of 2 Version: 11/30/2020 Project Name: Discharge Point: Treatment Wetland # Practice Drainage Area For Permit Coverage Not for Permit Coverage Total to Practice 1 Total Area (acres)2.060 0.000 2.060 2 1.310 0.000 1.310 3 0.000 0.000 0.000 WQV for credit WQV not for credit Total WQV 4 WQV to practice 0.1068 0.0000 0.1068 96 5 2 6 2 Response Attachment location 7 Plan Sheet C‐6 8 Detail Sheet D‐8 9 Plan Sheet C‐6 10 Detail Sheet D‐8 11*Detail Sheet D‐8 12*Detail Sheet D‐8 13*Detail Sheet D‐8 Response Attachment location 14 Forebay, Sheet C6 ↑Enter this value on the Standards Compliance Workbook Is outlet elevation designed such that a sub‐surface water level is maintained in the gravel wetland? If the gravel wetland is designed with an organic soil layer at the surface, have vertical perforated riser pipes been provided to deliver stormwater stormwater from the surface down to the gravel bed? Have the outfalls and the conveyance to the discharge point been designed and protected to avoid erosion? Practice Type Redeveloped Impervious Pre‐Treatment (4.3.6.3) Has pretreatment been provided for non‐rooftop runoff? Discharges to Cold or Warm Water Fishery? Modified CN for WQ (1.0ʺ) storm Note: Designers may use the Practice Drainage Area Runoff Calculator (second tab) for calculation of practice‐ specific runoff volumes for other treatment standards. Conveyance (4.3.5.2) Are inlets stabilized to ensure that non‐erosive conditions exist for at least the 1‐year, 24 hour storm? * Questions preceded by an asterix (*) may change based on previously entered values Have inlet pipes been set at the permanent pool or the base of the gravel bed? New Impervious (acres) Hillside @ OʹBrien Farm 4 1Treatment Wetlands (4.3.5) Has a low for orifice been provided to meet the the WQV and CPV extended Has a liner designed in accordance with Section 4.3.5.2 been provided if the infiltration rate exceed 0.05 inches per hour and the wetland is located above Yes No Yes No No No Yes Yes NoYes Cold Warm NoYes NoYes NoYes Shallow surface wetland Gravel wetland Page 1 of 4 15 Response Attachment location 16 ft3 1320 17 ft3 2050 18 ft3 3370 19* 20* 21 72.4%Yes 22 23 24 ac‐ft Enter this on the eNOI Response Attachment location 25 N/A 26 N/A 27 Detail SheetD‐8 28 N/A 29 Detail SheetD‐8 30 N/A Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has been provided within the application. What is the volume stored in the forebay or other volumetric pre‐ treatment if used? (minimum 10% WQV) What is the volume stored in the permanent pool? What is the total WQV stored at the normal water level (pre‐ treatment + permanent pool)? Does the pre‐treatment volume plus the permanent pool equal at least 50% of the WQV? Has a planting plan been prepared showing how aquatic and terrestrial areas will be stabilized, including plant species, plant locations, sources of plant material and any required soil amendments? Are any donor organic soils used in the practice obtained from a source other than natural wetlands? Is the remaining WQV provided for by extended detention over 24 hours? Are all deep pool areas of ≥ 4 feet depth with side slopes steeper than 4:1 (H:V) surrounded by a safety bench with ≤6% slope extending 10 feet outward from the normal water edge to the toe of the side slope? Landscaping (4.3.6.5) Treatment (4.3.6.4) Has a minimum flow path at normal water level of 3:1 been provided? Does the planting plan specify that no woody vegetation >2 inches in diameter shall be planted or allowed to grow on the dam, within 15 feet of the dam or the toe of the embankment, or within 25 of a principal spillway outlet? What type of pretreatment is being used? Has an aquatic been been provided that extends at least 5 feet inward from the normal water edge and is no more than 18 inches deep? Has a setback been provided that extends 25 feet from the maximum design water surface elevation of the practice? What is the Storage Volume of the practice. Include the permanent pool and any volume used for providing extended detention. Swale Filter Strip Forebay (10% WQv) Deep Sump Catch Basins Proprietary NoYes NoYes NoYes Yes No NoYes NoYes NoYes NoYes NoYes NoYes Page 2 of 4 Practice Drainage Area Runoff Calculator Project Name: Discharge Point: Treatment Wetland # Precipitation Data NOAA Atlas 14 Storm WQ Storm 1 yr, 24 hr 10 yr, 24 hr 100 yr, 24 hr Precipitation (inches) 1.00 1.90 3.25 4.85 Drainage Area Information Landuse A B C D Grass 0.000 0.000 0.000 0.000 0.000 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 1.030 1.030 0.000 0.000 2.060 Pavement, roofs, and other impervious 0.000 0.000 0.000 0.000 0.000 Total 1.030 1.030 0.000 0.000 2.060 Landuse A B C D Grass 0.375 0.375 0.000 0.000 0.750 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 0.000 0.000 0.000 0.000 0.000 Pavement, roofs, and other impervious 0.655 0.655 0.000 0.000 1.310 Total 1.030 1.030 0.000 0.000 2.060 TV of upstream practices:0.000 ac‐ft TV credit of this practice:0.000 ac‐ft Treatment Standard Required Treatment Volume Post Development Runoff Volume Pre‐ development Runoff Volume Post Composite CN (to practice) CNAdj (with TV practice credit) Pre Composite CN Channel Protection (Hydrologic Condition Method) 0.1839 0.1846 0.0007 91 91 54 Overbank Flood 0.3211 0.3439 0.0228 88 88 50 Extreme Flood 0.4711 0.5490 0.0779 85 85 46 Information for Calculating TC by the Watershed Lag Method 1 yr 10 yr 100 yr Time of Concentration, TC (min)Hydraulic Length, l (ft) Average Catchment Slope, Y (%) Hillside @ OʹBrien Farm 4 1 Hydrologic Soil Group Total (acres) This tool may be used to calculate the required treatment volumes for the area draining to an individual practice where the practices drainage area is only a portion of of the area draining to a discharge point. Where the practice receives runoff from the entire area to a discharge point, this calculator will give the same information as the Standards Compliance Workbook. * Preciptation values shall be obtained from Pre Development Land Use (acres) Hydrologic Soil Group Total (acres) Post Development Land Use (acres) Pre Development 5.00% 350.00 12.4 13.8 15.0 Post Development, upstream of practice 5.00% 350.00 4.1 4.7 5.3 Post Development, with TV credit from practice 0.00% 0.00 0.0 0.0 0.0 Practice Drainage Area Runoff Calculator Project Name: Discharge Point: Treatment Wetland # Precipitation Data NOAA Atlas 14 Storm WQ Storm 1 yr, 24 hr 10 yr, 24 hr 100 yr, 24 hr Precipitation (inches) 1.00 1.90 3.25 4.85 Drainage Area Information Landuse A B C D Grass 0.000 0.000 0.000 0.000 0.000 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 3.530 3.530 0.000 0.000 7.060 Pavement, roofs, and other impervious 0.000 0.000 0.000 0.000 0.000 Total 3.530 3.530 0.000 0.000 7.060 Landuse A B C D Grass 1.360 1.360 0.000 0.000 2.720 Meadow 0.000 0.000 0.000 0.000 0.000 Woods 0.000 0.000 0.000 0.000 0.000 Pavement, roofs, and other impervious 2.170 2.170 0.000 0.000 4.340 Total 3.530 3.530 0.000 0.000 7.060 TV of upstream practices:0.000 ac‐ft TV credit of this practice:0.000 ac‐ft Treatment Standard Required Treatment Volume Post Development Runoff Volume Pre‐ development Runoff Volume Post Composite CN (to practice) CNAdj (with TV practice credit) Pre Composite CN Channel Protection (Hydrologic Condition Method) 0.6097 0.6121 0.0024 90 90 54 Overbank Flood 1.0658 1.1440 0.0782 87 87 50 Extreme Flood 1.5659 1.8329 0.2670 84 84 46 Information for Calculating TC by the Watershed Lag Method 1 yr 10 yr 100 yr Time of Concentration, TC (min)Hydraulic Length, l (ft) Average Catchment Slope, Y (%) Hillside @ OʹBrien Farm 4 2 Hydrologic Soil Group Total (acres) This tool may be used to calculate the required treatment volumes for the area draining to an individual practice where the practices drainage area is only a portion of of the area draining to a discharge point. Where the practice receives runoff from the entire area to a discharge point, this calculator will give the same information as the Standards Compliance Workbook. * Preciptation values shall be obtained from Pre Development Land Use (acres) Hydrologic Soil Group Total (acres) Post Development Land Use (acres) Pre Development 7.30% 450.00 12.5 13.9 15.2 Post Development, upstream of practice 7.30% 450.00 4.3 4.9 5.5 Post Development, with TV credit from practice 0.00% 0.00 0.0 0.0 0.0 Version: 11/30/2020 Project Name: Discharge Point: Infiltration Practice # Practice Drainage Area For Permit Coverage Not for Permit Coverage Total to Practice 1 Total Area (acres)24.150 0.000 24.150 2 8.030 0.000 8.030 3 0.000 0.000 0.000 WQV for credit WQV not for credit Total WQV 4 WQV to practice 0.7029 0.0000 0.7029 91 5 0.6173 6 1 Response Attachment location 7 Existing Practice 8*Existing Practice 9 Existing Practice 10 Existing Practice 11 Existing Practice 12 Existing Practice 13*Existing Practice 0 1 Response Attachment location Redeveloped Impervious Design Volume for Infiltration (TV) Modified CN for WQ (1.0ʺ) storm Note: If the practice is designed to infiltrate the WQV, then TV = WQV. Designers may use the Practice Drainage Area Runoff Calculator (second tab) for calculation of practice‐specific runoff volumes for other treatment standards. Sizing of the filter bed area/swale bottom need to consider the desired treatment volume (see treatment section). Some design requirements will change based on the size of storm the practice is designed to treat. ← Tv value to enter on the Standards Compliance Workbook for this practice Is the seasonal high groundwater table (SHGWT) separated at least three (3) feet vertically from the bottom of the practice? New Impervious (acres) Hillside @ OʹBrien Farm 4 AInfiltration (4.3.3) Feasibility (4.3.3.1) Has the infiltration rate (fc) of the underlying soil been confirmed to be at least 0.2 inches per hour by the soil testing requirements in Section 4.3.3.2? Practice Type * Questions preceded by an asterix (*) may change based on previously entered values Has a groundwater mounding analysis been performed if the practice is designed to infiltrate >1 year storm and the SHGWT <4 feet? 1 Have the proper setback requirements for groundwater source protection been observed? (Section 4.3.3.1) Has the practice been placed so that it will not cause intrusion problems for down‐gradient structures? (Section 4.3.3.1) Is the site free from subsurface contamination or prior approval obtained from the Agency? (If approval is required based on prior contamination, include Conveyance (4.3.3.2) Is the basin designed with side slopes of 2:1 or flatter? Yes No NoYes NoYes Infiltration Basin Infiltration Trench Infiltration Chambers Drywell(s) Yes No Yes No Yes No Yes No Page 1 of 2 14 Existing Practice 15 Existing Practice 16 Existing Practice Response Attachment location 17 Wet Pond A/Forebays 18 ≤ 2 in/hr Existing Practice > 2 in/hr Existing Practice 20*Existing Practice 21*Existing Practice 2 TRUE Response Attachment location 22 Existing Practice 23*Existing Practice 24 (ac‐ft)Enter this on the eNOI 25 TV (ac‐ft) 0 Response Attachment location 26 Existing Practice 19* Treatment Volume (TV) for infiltration practices may be calculated using the equations provided as design guidance in Section 4.3.3.5 OR by demonstrating infiltration of the TV using TR‐20 or an approved equavalent. What is the treatment volume provided by the STP? What is the physical storage volume up to the overflow? Pre‐Treatment (4.3.3.3) Has pretreatment been provided for non‐rooftop runoff? Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has been provided within the application. Does the site plan specify a landscaping plan that ensures dense and vigorous vegetation over the contributing pervious drainage areas and the practice? Landscaping (4.3.2.5) Treatment (4.3.2.4) ↑ Enter this value on the Standards Has direct access been provided to the practice for maintenance and rehabilitation? Is the forebay separated at least three (3) feet from the SHGWT or located over impermeable soils? What type of pretreatment is being used? Is the infiltration rate (fc) greater than or less than 2 inches per hour? Is the forebay sized to hold at least 50% of the WQv? If the practice is designed to infiltrate <1 year storm and runoff is delivered by the main conveyance system, has it been designed as an off‐line practice? Have the outfalls and the conveyance to the discharge point been designed/protected to avoid erosive velocities? Is the practice designed to completely dewater the treatment volume (TV) within 48 hours after the storm event? Swale Filter Strip Forebay Deep Sump Catch Basins Proprietary Yes No Yes No NoYes NoYes Yes No Yes No NoYes Yes No Yes No Page 2 of 2 Version: 11/30/2020 Project Name: Discharge Point: Wet Pond # Practice Drainage Area For Permit Coverage Not for Permit Coverage Total to Practice 1 Total Area (acres)24.150 0.000 24.150 2 8.030 0.000 8.030 3 0.000 0.000 0.000 WQV for credit WQV not for credit Total WQV 4 WQV to practice 0.7029 0.0000 0.7029 91 5 2 Response Attachment location 6 NA 0 1 Response Attachment location 7 Existing Pond 8 Existing Pond 9 Existing Pond 10 Existing Pond 11 Existing Pond 12 NA 13 Existing Pond 14* Does the design specify an outlet that is stable for the Q10 storm event? Is the outlet control structure located within the embankment for maintenance access and safety? New Impervious (acres) Hillside @ OʹBrien Farm 4 AWet Pond (4.3.6) Redeveloped Impervious Discharges to Cold or Warm Water Fishery? Modified CN for WQ (1.0ʺ) storm Note: Designers may use the Practice Drainage Area Runoff Calculator (second tab) for calculation of practice‐ specific runoff volumes for other treatment standards. Feasibility (4.3.6.1) If receiving water from a stormwater hotspot, is the pond lined and prevented from intercepting groundwater? * Questions preceded by an asterix (*) may change based on previously entered values Conveyance (4.3.6.2) Has a emergency spillway been provided to safely convey the 100‐year storm without overtopping the embankment? ↑Enter this value on the Standards Compliance Workbook Are end walls above pipe outfalls greater than 30 inches in diameter fenced with pipe or rebar at 8 inch intervals? Has a low flow orifice been provided to meet the WQV and CPV extended detention requirements without clogging? Have the outfalls and the conveyance to the discharge point been designed and protected to avoid erosive velocities? Are inlets stabilized to ensure that non‐erosive conditions exist during events up to the 10‐year, 24 hour storm? Yes No Yes No Yes No No No Yes Yes Cold Warm NoYes NoYes NoYes NoYes Page 1 of 2 Response Attachment location 15 16 Response Attachment location 17 ft3 3420 18 ft3 23564 19 ft3 26984 20* 21 #########Yes 22 23 Basin 24 25 ac‐ft Enter this on the eNOI Response Attachment location 26 Existing Pond 27 Existing Pond 28 Existing Pond 29 Existing Pond Is the remaining WQV provided for by extended detention over 24 hours? What type of pretreatment is being used? Has the permanent pool been excluded from calculations for storms greater than the water quality event (1ʺ storm)? Pre‐Treatment (4.3.6.3) Has pretreatment been provided for non‐rooftop runoff? Are all deep pool areas of ≥ 4 feet depth with side slopes steeper than 4:1 (H:V) surrounded by a safety bench with ≤6% slope extending 10 feet outward from the normal water edge to the toe of the side slope? Landscaping (4.3.6.5) Treatment (4.3.6.4) Is at least 25% of the WQV stored in deep water zones with a depth between four (4) and eight (8) feet? What is the volume stored in the forebay or other volumetric pre‐ treatment if used? (minimum 10% WQV) What is the volume stored in the permanent pool? What is the total WQV stored at the normal water level (pre‐ treatment + permanent pool)? Does the pre‐treatment volume plus the permanent pool equal at least 50% of the WQV? What is the Storage Volume of the practice. Include the permanent pool and any volume used for providing extended detention. Has a minimum flow path at normal water level of 3:1 been provided? Has an aquatic been been provided that extends at least 5 feet inward from the normal water edge and is no more than 18 inches deep? Does the planting plan specify that no woody vegetation >2 inches in diameter shall be planted or allowed to grow on or within 15 feet of the dam or the toe of the embankment? Attachment location: Indicate the specific location (i.e. appendix, page, plan sheet) where the requisite support documentation has been provided within the application. Has a planting plan been prepared showing how aquatic and terrestrial areas will be stabilized, including plant species, plant locations, sources of plant material and any required soil amendments? Swale Filter Strip Forebay (10% WQv) Deep Sump Catch Basins Proprietary NoYes NoYes NoYes NoYes NoYes Yes No No No Yes Yes NoYes Page 2 of 2