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HomeMy WebLinkAboutSD-20-24 SP-20-029 - Supplemental - 0510 Shelburne Road (17)478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Bacon Street Properties, LLC 510 Shelburne Road South Burlington, VT Stormwater Design Brief June 18, 2020 1.Project Description The applicant, Bacon Street Properties, LLC, is proposing to remove the existing gas station and construct a new three story commercial building at 510 Shelburne Road in South Burlington, Vermont. The existing 0.68 acre site is almost entirely impervious and contains an abandoned gas station and associated gravel/paved parking which will be removed as part of this project. The project will include the addition of a new 4930 SF commercial building with a one way slip lane and paved parking area on the eastern portion of the site. The project will result in a decrease of impervious surface on site from + 0.61 acres to + 0.54 acres. As the total impervious on the proposed site will exceed 0.5 acres, stormwater management of the site’s runoff has been proposed to meet the requirements in section 12.03 of the South Burlington Land Development Regulations. Section 12.03(C)(1) & (2) requires that the site be designed to allow for infiltration, or a treatment method meeting the Vermont Stormwater Management Manual, of the Water Quality Volume (WQv) and to ensure that post-construction peak runoff rates for the 1-yr, 24-hour (2.1 in) rainfall event does not exceed the peak runoff rate for the same storm event under the existing site conditions. The existing site has had a history of soil contamination from a past underground fuel tank spill. KAS Consulting is in contact with the VT DEC regarding the on-site contamination and a remediation/correction action plan is being prepared for the site. Due to the existing contamination and “hotspot” nature of the site, infiltration is not possible. This stormwater design proposes bioretention practices which will be lined or contained, allowing for no on-site infiltration. The proposed stormwater treatment system is designed to connect to an existing drainage manhole in Shelburne Road with discharge to the municipal stormwater system. The stormwater treatment system described in this narrative ensures that the regulations outlined in Section 12.03 have been met. 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Page 2 of 5 Stormwater Narrative – Bacon Street Properties June 18, 2020 2.Receiving Waters Stormwater runoff from this site currently discharges to the municipal catch basin system on Shelburne Road and Bacon Street, which heads north along Shelburne Road with a final discharge to an unnamed tributary near Prospect Parkway and finally to Lake Champlain. 3.Existing Conditions The site currently consists of an approximately 0.68 acre parcel with an abandoned gas station and associated gravel/paved parking area. The property has frontage on both Shelburne Road and Bacon Street. Impervious cover on the site is currently approximately 0.61 acres. The site is very flat is little to no elevation change throughout. Soils on site are entirely mapped as Hydrologic Soil Group (HSG) D. 4.Existing Stormwater System No stormwater treatment, stormwater infrastructure, or stormwater permits exist on the site. Runoff from the property currently overland flows over the flat site and discharges onto the neighboring properties and adjacent roadways. Existing runoff from the site directly enters the municipal storm system via catch basins on Shelburne Road and Bacon Street. 5.Proposed Stormwater System The proposed stormwater system utilizes two Filterra bioretention units to treat runoff from the rear parking lot prior to discharge to the municipal system. These Filterra units will contain a grate inlet with a separate sump allowing for pretreatment. The units will also contain bypass piping, allowing larger storms to bypass the system. The Filterra units are approved as a Tier 2 practice by the VT DEC. The approval letter is included with this application. Stormwater runoff from the southern paved area of the site and a portion of the new rooftop will be routed to a lined bioretention basin in a curbed area on the southern edge of the site. A Rain Guardian Turret is proposed along the new southern pavement allowing for pretreatment of overland runoff prior to reaching this bioretention basin. The Rain Guardian Turret is approved by the VT 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Page 3 of 5 Stormwater Narrative – Bacon Street Properties June 18, 2020 DEC as a pretreatment practice and the approval letter is included with this application. The bioretention basin is proposed to have an underdrain connected to an outlet control structure, with final discharge to the municipal storm system. Stormwater runoff from the northern portion of the site and the remaining section of new rooftop will be routed to a lined bioretention basin on the west side of the building. A pea-stone diaphragm is proposed along the edge of the bioretention practice to allow for pretreatment of overland runoff prior to entering the basin. The bioretention basin is proposed to have an underdrain connected to an outlet control structure, with final discharge to the municipal storm system. 6. South Burlington Stormwater Management Standards Compliance As noted above, the site must comply with section 12.03 of the current City of South Burlington Land Use Development Regulations. Water Quality Volume (WQv) Standard Per Section 12.03 C(1), the WQv shall not leave the lot via overland runoff and shall be infiltrated using Low Impact Development (LID) practices. If It is not possible to infiltrate due to the presence of a “stormwater hotspot” (12.03C(1)(a)(v)) then the WQv shall be treated by stormwater treatment practices meeting the Vermont Stormwater Management Manual. Due to the “hotspot” nature of the site, infiltration cannot be utilized. The site design proposes two Filterra bioretention units and two bioretention basins. The Filterra units have been specifications in accordance with the manufacturer’s specifications for incoming runoff volume and flow rate. The Filterra specifications and design information have been included with this application. Both bioretention basins have been designed in accordance with the 2017 State Stormwater Management Manual. The area of the bioretention basins are sized as follows: Drainage Area 3 – Bioretention Area 1 WQv Treatment Volume = 0.008 acft = 349 CF Required Bioretention Filter Area Per VSMM 4.3.1.4 = (349 CF)(2 foot filter depth)/(1 ft/day)(2 foot filter depth)(2 days drain time) = 175 SF Bioretention Filter Area Provided = 183 SF 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Page 4 of 5 Stormwater Narrative – Bacon Street Properties June 18, 2020 Drainage Area 4 – Bioretention Area 2 WQv Treatment Volume = 0.004 acft = 175 CF Required Bioretention Filter Area Per VSMM 4.3.1.4 = (175 CF)(2 foot filter depth)/(1 ft/day)(2 foot filter depth)(2 days drain time) = 88 SF Bioretention Filter Area Provided = 179 SF Drainage areas used for modeling are shown on plan sheet C4-01 and a HydroCAD report is included ensuring that Section 12.03(C)(1) has been met. One-Year Storm (CPv) Standard Per Section 12.03 C(2), the post construction peak runoff rate for the one-year, twenty-four hour (2.1 inch) rain event shall not exceed the existing peak runoff rate for the same storm event from the site under current conditions. Modeling has been provided to ensure that post development runoff rates from the 1-year storm will be less than pre-development levels. Drainage Structures In accordance with section 12.03(E) of the regulations, drainage structures must safely pass runoff from the 25 year storm event. Modeling has been provided showing that the site’s post development peak discharge rate will be less than pre-development levels and as such will have a reduced impact on the city’s stormwater drainage system. 7. Maintenance Stormwater treatment systems require maintenance to ensure proper functionality. Once constructed, the designer will be required to submit a Statement of Compliance to the City of South Burlington and the owners to verify that the stormwater treatment system was built as designed. The Filterra units will be installed by the manufacturer and inspections/maintenance will adhere to the manufacturer’s recommendations. The bioretention basins will be checked annually for signs of erosion, sediment build-up or debris, vegetated areas which need maintenance, illicit discharges, re-routing of stormwater or any other issues which may cause the stormwater system to not properly function. The owner will be responsible for performing maintenance and/or repairs as necessary. 478 Blair Park Road Williston, VT 05495 802 879 6331www.tcevt.com42 Mapleville Depot Road St. Albans, VT 05478 802 528 5116 Civil Engineering Environmental Services Land Surveying Landscape Architecture Page 5 of 5 Stormwater Narrative – Bacon Street Properties June 18, 2020 8. Conclusions A summary of the hydrologic performance of the site under existing conditions and proposed conditions is provided in the table below: Rain Event Existing Peak Discharge Rate (cfs) Proposed, Pre-Routed Peak Discharge Rate (cfs) Proposed, Routed Peak Discharge Rate (cfs) 1”, 24-hour (WQv)0.84 0.83 0.50 1-yr, 24-hr (CPv)2.06 1.96 1.72 25-yr, 24-hr 4.18 3.97 3.64 The development of this parcel, along with the implementation of the proposed stormwater management system, will improve the hydrologic conditions for the down gradient recipients of the site’s runoff. Further, the proposed site design meets all necessary stormwater treatment requirements set forth by the City of South Burlington. 1S Existing Property 2S DA1 5S DA4 6S DA2 12S DA3 16S DA1 17S DA4 18S DA2 19S DA3 11R PIPE 1 12R PIPE 2 3P Offsite 4P OFFSITE 5P Filterra FTPD0608-G 10P Bioretention #2 14P Filterra FTPD0610-G 15P Bioretention #1 20P Offsite Pre-Routed Routing Diagram for 19-202 Stormwater Prepared by Trudell Consulting Engineers, Printed 6/18/2020 HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Subcat Reach Pond Link 19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 2HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.071 84 50-75% Grass cover, Fair, HSG D (1S) 0.200 80 >75% Grass cover, Good, HSG D (2S, 5S, 6S, 12S, 16S, 17S, 18S, 19S) 0.350 96 Gravel surface, HSG D (1S) 1.049 98 Paved parking, HSG D (1S, 2S, 5S, 6S, 16S, 17S, 18S) 0.271 98 Roofs, HSG D (1S, 5S, 12S, 17S, 19S) 0.051 98 Unconnected pavement, HSG D (12S, 19S) 1.992 95 TOTAL AREA 19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 3HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 1.992 HSG D 1S, 2S, 5S, 6S, 12S, 16S, 17S, 18S, 19S 0.000 Other 1.992 TOTAL AREA 19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 4HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.000 0.071 0.000 0.071 50-75% Grass cover, Fair 1S 0.000 0.000 0.000 0.200 0.000 0.200 >75% Grass cover, Good 2S, 5S, 6S, 12S, 16S, 17S, 18S, 19S 0.000 0.000 0.000 0.350 0.000 0.350 Gravel surface 1S 0.000 0.000 0.000 1.049 0.000 1.049 Paved parking 1S, 2S, 5S, 6S, 16S, 17S, 18S 0.000 0.000 0.000 0.271 0.000 0.271 Roofs 1S, 5S, 12S, 17S, 19S 0.000 0.000 0.000 0.051 0.000 0.051 Unconnected pavement 12S, 19S 0.000 0.000 0.000 1.992 0.000 1.992 TOTAL AREA 19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 5HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 11R 205.98 205.59 97.0 0.0040 0.020 15.0 0.0 0.0 2 12R 205.54 205.40 35.0 0.0040 0.020 18.0 0.0 0.0 3 10P 206.25 206.00 17.0 0.0147 0.020 12.0 0.0 0.0 4 15P 206.30 205.90 58.0 0.0069 0.020 12.0 0.0 0.0 Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 6HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=29,621 sf 38.09% Impervious Runoff Depth=0.64"Subcatchment 1S: Existing Property Tc=0.0 min CN=96 Runoff=0.84 cfs 0.036 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=0.73"Subcatchment 2S: DA1 Tc=0.0 min CN=96 Runoff=0.26 cfs 0.012 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=0.58"Subcatchment 5S: DA4 Tc=0.0 min CN=93 Runoff=0.09 cfs 0.004 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=0.74"Subcatchment 6S: DA2 Tc=0.0 min CN=97 Runoff=0.30 cfs 0.013 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=0.59"Subcatchment 12S: DA3 Tc=0.0 min CN=93 Runoff=0.18 cfs 0.008 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=0.73"Subcatchment 16S: DA1 Tc=0.0 min CN=96 Runoff=0.26 cfs 0.012 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=0.58"Subcatchment 17S: DA4 Tc=0.0 min CN=93 Runoff=0.09 cfs 0.004 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=0.74"Subcatchment 18S: DA2 Tc=0.0 min CN=97 Runoff=0.30 cfs 0.013 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=0.59"Subcatchment 19S: DA3 Tc=0.0 min CN=93 Runoff=0.18 cfs 0.008 af Avg. Flow Depth=0.38' Max Vel=1.70 fps Inflow=0.56 cfs 0.025 afReach 11R: PIPE 1 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs Outflow=0.51 cfs 0.025 af Avg. Flow Depth=0.35' Max Vel=1.63 fps Inflow=0.51 cfs 0.027 afReach 12R: PIPE 2 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs Outflow=0.50 cfs 0.027 af Inflow=0.84 cfs 0.036 afPond 3P: Offsite Primary=0.84 cfs 0.036 af Inflow=0.50 cfs 0.027 afPond 4P: OFFSITE Primary=0.50 cfs 0.027 af Inflow=0.26 cfs 0.012 afPond 5P: Filterra FTPD0608-G Primary=0.26 cfs 0.012 af Peak Elev=209.50' Storage=118 cf Inflow=0.09 cfs 0.004 afPond 10P: Bioretention #2 Outflow=0.00 cfs 0.001 af Inflow=0.30 cfs 0.013 afPond 14P: Filterra FTPD0610-G Primary=0.30 cfs 0.013 af Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 7HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Peak Elev=210.48' Storage=353 cf Inflow=0.18 cfs 0.008 afPond 15P: Bioretention #1 Outflow=0.00 cfs 0.000 af Inflow=0.83 cfs 0.037 afPond 20P: Offsite Pre-Routed Primary=0.83 cfs 0.037 af Total Runoff Area = 1.992 ac Runoff Volume = 0.111 af Average Runoff Depth = 0.67" 31.17% Pervious = 0.621 ac 68.83% Impervious = 1.371 ac Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 8HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Property [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.84 cfs @ 11.89 hrs, Volume=0.036 af, Depth= 0.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 15,246 96 Gravel surface, HSG D 9,322 98 Paved parking, HSG D 1,960 98 Roofs, HSG D 3,093 84 50-75% Grass cover, Fair, HSG D 29,621 96 Weighted Average 18,339 61.91% Pervious Area 11,282 38.09% Impervious Area Subcatchment 1S: Existing Property Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.9 0.85 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 1" WQv Rainfall=1.00" Runoff Area=29,621 sf Runoff Volume=0.036 af Runoff Depth=0.64" Tc=0.0 min CN=96 0.84 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 9HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.26 cfs @ 11.89 hrs, Volume=0.012 af, Depth= 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 2S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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 Type II 24-hr 1" WQv Rainfall=1.00" Runoff Area=8,454 sf Runoff Volume=0.012 af Runoff Depth=0.73" Tc=0.0 min CN=96 0.26 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 10HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.09 cfs @ 11.89 hrs, Volume=0.004 af, Depth= 0.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 5S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 1" WQv Rainfall=1.00" Runoff Area=3,595 sf Runoff Volume=0.004 af Runoff Depth=0.58" Tc=0.0 min CN=93 0.09 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 11HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.30 cfs @ 11.89 hrs, Volume=0.013 af, Depth= 0.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 6S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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" WQv Rainfall=1.00" Runoff Area=9,402 sf Runoff Volume=0.013 af Runoff Depth=0.74" Tc=0.0 min CN=97 0.30 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 12HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.18 cfs @ 11.89 hrs, Volume=0.008 af, Depth= 0.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 12S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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 1" WQv Rainfall=1.00" Runoff Area=7,131 sf Runoff Volume=0.008 af Runoff Depth=0.59" Tc=0.0 min CN=93 0.18 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 13HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 16S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.26 cfs @ 11.89 hrs, Volume=0.012 af, Depth= 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 16S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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 Type II 24-hr 1" WQv Rainfall=1.00" Runoff Area=8,454 sf Runoff Volume=0.012 af Runoff Depth=0.73" Tc=0.0 min CN=96 0.26 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 14HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 17S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.09 cfs @ 11.89 hrs, Volume=0.004 af, Depth= 0.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 17S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type II 24-hr 1" WQv Rainfall=1.00" Runoff Area=3,595 sf Runoff Volume=0.004 af Runoff Depth=0.58" Tc=0.0 min CN=93 0.09 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 15HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 18S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.30 cfs @ 11.89 hrs, Volume=0.013 af, Depth= 0.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 18S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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" WQv Rainfall=1.00" Runoff Area=9,402 sf Runoff Volume=0.013 af Runoff Depth=0.74" Tc=0.0 min CN=97 0.30 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 16HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 19S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.18 cfs @ 11.89 hrs, Volume=0.008 af, Depth= 0.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1" WQv Rainfall=1.00" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 19S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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 1" WQv Rainfall=1.00" Runoff Area=7,131 sf Runoff Volume=0.008 af Runoff Depth=0.59" Tc=0.0 min CN=93 0.18 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 17HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 11R: PIPE 1 [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area =0.410 ac, 92.56% Impervious, Inflow Depth = 0.74" for 1" WQv event Inflow =0.56 cfs @ 11.89 hrs, Volume=0.025 af Outflow =0.51 cfs @ 11.91 hrs, Volume=0.025 af, Atten= 9%, Lag= 1.1 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.70 fps, Min. Travel Time= 1.0 min Avg. Velocity = 0.47 fps, Avg. Travel Time= 3.4 min Peak Storage= 31 cf @ 11.90 hrs Average Depth at Peak Storage= 0.38' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 2.66 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 97.0' Slope= 0.0040 '/' Inlet Invert= 205.98', Outlet Invert= 205.59' Reach 11R: PIPE 1 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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=0.410 ac Avg. Flow Depth=0.38' Max Vel=1.70 fps 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs 0.56 cfs 0.51 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 18HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 12R: PIPE 2 [52] Hint: Inlet/Outlet conditions not evaluated [61] Hint: Exceeded Reach 11R outlet invert by 0.30' @ 11.90 hrs Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 0.49" for 1" WQv event Inflow =0.51 cfs @ 11.91 hrs, Volume=0.027 af Outflow =0.50 cfs @ 11.92 hrs, Volume=0.027 af, Atten= 3%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.63 fps, Min. Travel Time= 0.4 min Avg. Velocity = 0.47 fps, Avg. Travel Time= 1.2 min Peak Storage= 11 cf @ 11.91 hrs Average Depth at Peak Storage= 0.35' Bank-Full Depth= 1.50' Flow Area= 1.8 sf, Capacity= 4.32 cfs 18.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 35.0' Slope= 0.0040 '/' Inlet Invert= 205.54', Outlet Invert= 205.40' Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 19HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Reach 12R: PIPE 2 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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=0.656 ac Avg. Flow Depth=0.35' Max Vel=1.63 fps 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs 0.51 cfs 0.50 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 20HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 3P: Offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.680 ac, 38.09% Impervious, Inflow Depth = 0.64" for 1" WQv event Inflow =0.84 cfs @ 11.89 hrs, Volume=0.036 af Primary =0.84 cfs @ 11.89 hrs, Volume=0.036 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 3P: Offsite Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.9 0.85 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=0.680 ac0.84 cfs0.84 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 21HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 4P: OFFSITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 0.49" for 1" WQv event Inflow =0.50 cfs @ 11.92 hrs, Volume=0.027 af Primary =0.50 cfs @ 11.92 hrs, Volume=0.027 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 4P: OFFSITE Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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=0.656 ac0.50 cfs0.50 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 22HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 5P: Filterra FTPD0608-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.194 ac, 91.66% Impervious, Inflow Depth = 0.73" for 1" WQv event Inflow =0.26 cfs @ 11.89 hrs, Volume=0.012 af Primary =0.26 cfs @ 11.89 hrs, Volume=0.012 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 5P: Filterra FTPD0608-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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=0.194 ac0.26 cfs0.26 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 23HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 10P: Bioretention #2 Inflow Area =0.083 ac, 70.74% Impervious, Inflow Depth = 0.58" for 1" WQv event Inflow =0.09 cfs @ 11.89 hrs, Volume=0.004 af Outflow =0.00 cfs @ 12.79 hrs, Volume=0.001 af, Atten= 95%, Lag= 54.2 min Primary =0.00 cfs @ 12.79 hrs, Volume=0.001 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 209.50' @ 12.79 hrs Surf.Area= 292 sf Storage= 118 cf Plug-Flow detention time= 352.2 min calculated for 0.001 af (33% of inflow) Center-of-Mass det. time= 211.0 min ( 997.0 - 786.0 ) Volume Invert Avail.Storage Storage Description #1 209.00'295 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.00 179 109.0 0 0 179 210.00 430 134.8 295 295 694 Device Routing Invert Outlet Devices #1 Primary 206.25'12.0" Round Culvert L= 17.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.25' / 206.00' S= 0.0147 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 209.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.00 cfs @ 12.79 hrs HW=209.50' (Free Discharge) 1=Culvert (Passes 0.00 cfs of 4.95 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.00 cfs @ 0.21 fps) Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 24HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 10P: Bioretention #2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=0.083 ac Peak Elev=209.50' Storage=118 cf 0.09 cfs 0.00 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 25HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 14P: Filterra FTPD0610-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.216 ac, 93.36% Impervious, Inflow Depth = 0.74" for 1" WQv event Inflow =0.30 cfs @ 11.89 hrs, Volume=0.013 af Primary =0.30 cfs @ 11.89 hrs, Volume=0.013 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 14P: Filterra FTPD0610-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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=0.216 ac0.30 cfs0.30 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 26HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 15P: Bioretention #1 Inflow Area =0.164 ac, 72.29% Impervious, Inflow Depth = 0.59" for 1" WQv event Inflow =0.18 cfs @ 11.89 hrs, Volume=0.008 af Outflow =0.00 cfs @ 0.00 hrs, Volume=0.000 af, Atten= 100%, Lag= 0.0 min Primary =0.00 cfs @ 0.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 210.48' @ 24.05 hrs Surf.Area= 399 sf Storage= 353 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 209.25'589 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.25 183 81.3 0 0 183 210.00 312 90.8 183 183 328 211.00 506 103.6 405 589 549 Device Routing Invert Outlet Devices #1 Primary 206.30'12.0" Round Culvert L= 58.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.30' / 205.90' S= 0.0069 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 210.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=209.25' (Free Discharge) 1=Culvert (Passes 0.00 cfs of 3.88 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 27HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 15P: Bioretention #1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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 Inflow Area=0.164 ac Peak Elev=210.48' Storage=353 cf 0.18 cfs 0.00 cfs Type II 24-hr 1" WQv Rainfall=1.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 28HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 20P: Offsite Pre-Routed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 0.68" for 1" WQv event Inflow =0.83 cfs @ 11.89 hrs, Volume=0.037 af Primary =0.83 cfs @ 11.89 hrs, Volume=0.037 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 20P: Offsite Pre-Routed Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.9 0.85 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=0.656 ac0.83 cfs0.83 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 29HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=29,621 sf 38.09% Impervious Runoff Depth=1.66"Subcatchment 1S: Existing Property Tc=0.0 min CN=96 Runoff=2.06 cfs 0.094 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=1.77"Subcatchment 2S: DA1 Tc=0.0 min CN=96 Runoff=0.61 cfs 0.029 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=1.51"Subcatchment 5S: DA4 Tc=0.0 min CN=93 Runoff=0.22 cfs 0.010 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=1.79"Subcatchment 6S: DA2 Tc=0.0 min CN=97 Runoff=0.68 cfs 0.032 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=1.53"Subcatchment 12S: DA3 Tc=0.0 min CN=93 Runoff=0.45 cfs 0.021 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=1.77"Subcatchment 16S: DA1 Tc=0.0 min CN=96 Runoff=0.61 cfs 0.029 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=1.51"Subcatchment 17S: DA4 Tc=0.0 min CN=93 Runoff=0.22 cfs 0.010 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=1.79"Subcatchment 18S: DA2 Tc=0.0 min CN=97 Runoff=0.68 cfs 0.032 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=1.53"Subcatchment 19S: DA3 Tc=0.0 min CN=93 Runoff=0.45 cfs 0.021 af Avg. Flow Depth=0.60' Max Vel=2.13 fps Inflow=1.29 cfs 0.061 afReach 11R: PIPE 1 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs Outflow=1.19 cfs 0.061 af Avg. Flow Depth=0.67' Max Vel=2.31 fps Inflow=1.79 cfs 0.081 afReach 12R: PIPE 2 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs Outflow=1.72 cfs 0.081 af Inflow=2.06 cfs 0.094 afPond 3P: Offsite Primary=2.06 cfs 0.094 af Inflow=1.72 cfs 0.081 afPond 4P: OFFSITE Primary=1.72 cfs 0.081 af Inflow=0.61 cfs 0.029 afPond 5P: Filterra FTPD0608-G Primary=0.61 cfs 0.029 af Peak Elev=209.57' Storage=139 cf Inflow=0.22 cfs 0.010 afPond 10P: Bioretention #2 Outflow=0.21 cfs 0.008 af Inflow=0.68 cfs 0.032 afPond 14P: Filterra FTPD0610-G Primary=0.68 cfs 0.032 af Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 30HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Peak Elev=210.62' Storage=411 cf Inflow=0.45 cfs 0.021 afPond 15P: Bioretention #1 Outflow=0.41 cfs 0.013 af Inflow=1.96 cfs 0.092 afPond 20P: Offsite Pre-Routed Primary=1.96 cfs 0.092 af Total Runoff Area = 1.992 ac Runoff Volume = 0.278 af Average Runoff Depth = 1.67" 31.17% Pervious = 0.621 ac 68.83% Impervious = 1.371 ac Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 31HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Property [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =2.06 cfs @ 11.89 hrs, Volume=0.094 af, Depth= 1.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 15,246 96 Gravel surface, HSG D 9,322 98 Paved parking, HSG D 1,960 98 Roofs, HSG D 3,093 84 50-75% Grass cover, Fair, HSG D 29,621 96 Weighted Average 18,339 61.91% Pervious Area 11,282 38.09% Impervious Area Subcatchment 1S: Existing Property Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Type II 24-hr 1-Yr Rainfall=2.10" Runoff Area=29,621 sf Runoff Volume=0.094 af Runoff Depth=1.66" Tc=0.0 min CN=96 2.06 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 32HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.61 cfs @ 11.89 hrs, Volume=0.029 af, Depth= 1.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 2S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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-Yr Rainfall=2.10" Runoff Area=8,454 sf Runoff Volume=0.029 af Runoff Depth=1.77" Tc=0.0 min CN=96 0.61 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 33HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.22 cfs @ 11.89 hrs, Volume=0.010 af, Depth= 1.51" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 5S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(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 Type II 24-hr 1-Yr Rainfall=2.10" Runoff Area=3,595 sf Runoff Volume=0.010 af Runoff Depth=1.51" Tc=0.0 min CN=93 0.22 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 34HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.68 cfs @ 11.89 hrs, Volume=0.032 af, Depth= 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 6S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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-Yr Rainfall=2.10" Runoff Area=9,402 sf Runoff Volume=0.032 af Runoff Depth=1.79" Tc=0.0 min CN=97 0.68 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 35HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.45 cfs @ 11.89 hrs, Volume=0.021 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 12S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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 1-Yr Rainfall=2.10" Runoff Area=7,131 sf Runoff Volume=0.021 af Runoff Depth=1.53" Tc=0.0 min CN=93 0.45 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 36HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 16S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.61 cfs @ 11.89 hrs, Volume=0.029 af, Depth= 1.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 16S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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-Yr Rainfall=2.10" Runoff Area=8,454 sf Runoff Volume=0.029 af Runoff Depth=1.77" Tc=0.0 min CN=96 0.61 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 37HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 17S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.22 cfs @ 11.89 hrs, Volume=0.010 af, Depth= 1.51" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 17S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(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 Type II 24-hr 1-Yr Rainfall=2.10" Runoff Area=3,595 sf Runoff Volume=0.010 af Runoff Depth=1.51" Tc=0.0 min CN=93 0.22 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 38HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 18S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.68 cfs @ 11.89 hrs, Volume=0.032 af, Depth= 1.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 18S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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-Yr Rainfall=2.10" Runoff Area=9,402 sf Runoff Volume=0.032 af Runoff Depth=1.79" Tc=0.0 min CN=97 0.68 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 39HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 19S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.45 cfs @ 11.89 hrs, Volume=0.021 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.10" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 19S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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 1-Yr Rainfall=2.10" Runoff Area=7,131 sf Runoff Volume=0.021 af Runoff Depth=1.53" Tc=0.0 min CN=93 0.45 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 40HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 11R: PIPE 1 [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area =0.410 ac, 92.56% Impervious, Inflow Depth = 1.78" for 1-Yr event Inflow =1.29 cfs @ 11.89 hrs, Volume=0.061 af Outflow =1.19 cfs @ 11.90 hrs, Volume=0.061 af, Atten= 7%, Lag= 0.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.13 fps, Min. Travel Time= 0.8 min Avg. Velocity = 0.60 fps, Avg. Travel Time= 2.7 min Peak Storage= 57 cf @ 11.89 hrs Average Depth at Peak Storage= 0.60' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 2.66 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 97.0' Slope= 0.0040 '/' Inlet Invert= 205.98', Outlet Invert= 205.59' Reach 11R: PIPE 1 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.410 ac Avg. Flow Depth=0.60' Max Vel=2.13 fps 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs 1.29 cfs 1.19 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 41HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 12R: PIPE 2 [52] Hint: Inlet/Outlet conditions not evaluated [62] Hint: Exceeded Reach 11R OUTLET depth by 0.08' @ 12.00 hrs [79] Warning: Submerged Pond 10P Primary device # 1 OUTLET by 0.20' [79] Warning: Submerged Pond 15P Primary device # 1 OUTLET by 0.30' Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 1.48" for 1-Yr event Inflow =1.79 cfs @ 11.91 hrs, Volume=0.081 af Outflow =1.72 cfs @ 11.92 hrs, Volume=0.081 af, Atten= 4%, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.31 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.64 fps, Avg. Travel Time= 0.9 min Peak Storage= 27 cf @ 11.92 hrs Average Depth at Peak Storage= 0.67' Bank-Full Depth= 1.50' Flow Area= 1.8 sf, Capacity= 4.32 cfs 18.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 35.0' Slope= 0.0040 '/' Inlet Invert= 205.54', Outlet Invert= 205.40' Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 42HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Reach 12R: PIPE 2 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Inflow Area=0.656 ac Avg. Flow Depth=0.67' Max Vel=2.31 fps 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs 1.79 cfs 1.72 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 43HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 3P: Offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.680 ac, 38.09% Impervious, Inflow Depth = 1.66" for 1-Yr event Inflow =2.06 cfs @ 11.89 hrs, Volume=0.094 af Primary =2.06 cfs @ 11.89 hrs, Volume=0.094 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 3P: Offsite Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Inflow Area=0.680 ac2.06 cfs2.06 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 44HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 4P: OFFSITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 1.48" for 1-Yr event Inflow =1.72 cfs @ 11.92 hrs, Volume=0.081 af Primary =1.72 cfs @ 11.92 hrs, Volume=0.081 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 4P: OFFSITE Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.656 ac1.72 cfs1.72 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 45HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 5P: Filterra FTPD0608-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.194 ac, 91.66% Impervious, Inflow Depth = 1.77" for 1-Yr event Inflow =0.61 cfs @ 11.89 hrs, Volume=0.029 af Primary =0.61 cfs @ 11.89 hrs, Volume=0.029 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 5P: Filterra FTPD0608-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)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=0.194 ac0.61 cfs0.61 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 46HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 10P: Bioretention #2 Inflow Area =0.083 ac, 70.74% Impervious, Inflow Depth = 1.51" for 1-Yr event Inflow =0.22 cfs @ 11.89 hrs, Volume=0.010 af Outflow =0.21 cfs @ 11.90 hrs, Volume=0.008 af, Atten= 7%, Lag= 0.9 min Primary =0.21 cfs @ 11.90 hrs, Volume=0.008 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 209.57' @ 11.90 hrs Surf.Area= 310 sf Storage= 139 cf Plug-Flow detention time= 160.3 min calculated for 0.008 af (74% of inflow) Center-of-Mass det. time= 66.8 min ( 836.0 - 769.2 ) Volume Invert Avail.Storage Storage Description #1 209.00'295 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.00 179 109.0 0 0 179 210.00 430 134.8 295 295 694 Device Routing Invert Outlet Devices #1 Primary 206.25'12.0" Round Culvert L= 17.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.25' / 206.00' S= 0.0147 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 209.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.20 cfs @ 11.90 hrs HW=209.57' (Free Discharge) 1=Culvert (Passes 0.20 cfs of 5.02 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.20 cfs @ 0.89 fps) Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 47HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 10P: Bioretention #2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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=0.083 ac Peak Elev=209.57' Storage=139 cf 0.22 cfs 0.21 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 48HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 14P: Filterra FTPD0610-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.216 ac, 93.36% Impervious, Inflow Depth = 1.79" for 1-Yr event Inflow =0.68 cfs @ 11.89 hrs, Volume=0.032 af Primary =0.68 cfs @ 11.89 hrs, Volume=0.032 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 14P: Filterra FTPD0610-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(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=0.216 ac0.68 cfs0.68 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 49HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 15P: Bioretention #1 Inflow Area =0.164 ac, 72.29% Impervious, Inflow Depth = 1.53" for 1-Yr event Inflow =0.45 cfs @ 11.89 hrs, Volume=0.021 af Outflow =0.41 cfs @ 11.92 hrs, Volume=0.013 af, Atten= 9%, Lag= 2.1 min Primary =0.41 cfs @ 11.92 hrs, Volume=0.013 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 210.62' @ 11.92 hrs Surf.Area= 427 sf Storage= 411 cf Plug-Flow detention time= 208.2 min calculated for 0.013 af (60% of inflow) Center-of-Mass det. time= 97.4 min ( 865.8 - 768.4 ) Volume Invert Avail.Storage Storage Description #1 209.25'589 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.25 183 81.3 0 0 183 210.00 312 90.8 183 183 328 211.00 506 103.6 405 589 549 Device Routing Invert Outlet Devices #1 Primary 206.30'12.0" Round Culvert L= 58.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.30' / 205.90' S= 0.0069 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 210.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.36 cfs @ 11.92 hrs HW=210.61' (Free Discharge) 1=Culvert (Passes 0.36 cfs of 4.87 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.36 cfs @ 1.07 fps) Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 50HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 15P: Bioretention #1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.164 ac Peak Elev=210.62' Storage=411 cf 0.45 cfs 0.41 cfs Type II 24-hr 1-Yr Rainfall=2.10"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 51HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 20P: Offsite Pre-Routed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 1.68" for 1-Yr event Inflow =1.96 cfs @ 11.89 hrs, Volume=0.092 af Primary =1.96 cfs @ 11.89 hrs, Volume=0.092 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 20P: Offsite Pre-Routed Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Inflow Area=0.656 ac1.96 cfs1.96 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 52HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=29,621 sf 38.09% Impervious Runoff Depth=3.50"Subcatchment 1S: Existing Property Tc=0.0 min CN=96 Runoff=4.18 cfs 0.199 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=3.62"Subcatchment 2S: DA1 Tc=0.0 min CN=96 Runoff=1.20 cfs 0.059 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=3.26"Subcatchment 5S: DA4 Tc=0.0 min CN=93 Runoff=0.47 cfs 0.022 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=3.65"Subcatchment 6S: DA2 Tc=0.0 min CN=97 Runoff=1.35 cfs 0.066 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=3.29"Subcatchment 12S: DA3 Tc=0.0 min CN=93 Runoff=0.94 cfs 0.045 af Runoff Area=8,454 sf 91.66% Impervious Runoff Depth=3.62"Subcatchment 16S: DA1 Tc=0.0 min CN=96 Runoff=1.20 cfs 0.059 af Runoff Area=3,595 sf 70.74% Impervious Runoff Depth=3.26"Subcatchment 17S: DA4 Tc=0.0 min CN=93 Runoff=0.47 cfs 0.022 af Runoff Area=9,402 sf 93.36% Impervious Runoff Depth=3.65"Subcatchment 18S: DA2 Tc=0.0 min CN=97 Runoff=1.35 cfs 0.066 af Runoff Area=7,131 sf 72.29% Impervious Runoff Depth=3.29"Subcatchment 19S: DA3 Tc=0.0 min CN=93 Runoff=0.94 cfs 0.045 af Avg. Flow Depth=0.95' Max Vel=2.46 fps Inflow=2.55 cfs 0.124 afReach 11R: PIPE 1 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs Outflow=2.38 cfs 0.124 af Avg. Flow Depth=1.07' Max Vel=2.74 fps Inflow=3.71 cfs 0.181 afReach 12R: PIPE 2 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs Outflow=3.64 cfs 0.181 af Inflow=4.18 cfs 0.199 afPond 3P: Offsite Primary=4.18 cfs 0.199 af Inflow=3.64 cfs 0.181 afPond 4P: OFFSITE Primary=3.64 cfs 0.181 af Inflow=1.20 cfs 0.059 afPond 5P: Filterra FTPD0608-G Primary=1.20 cfs 0.059 af Peak Elev=209.62' Storage=154 cf Inflow=0.47 cfs 0.022 afPond 10P: Bioretention #2 Outflow=0.45 cfs 0.020 af Inflow=1.35 cfs 0.066 afPond 14P: Filterra FTPD0610-G Primary=1.35 cfs 0.066 af Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 53HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Peak Elev=210.70' Storage=444 cf Inflow=0.94 cfs 0.045 afPond 15P: Bioretention #1 Outflow=0.89 cfs 0.037 af Inflow=3.97 cfs 0.192 afPond 20P: Offsite Pre-Routed Primary=3.97 cfs 0.192 af Total Runoff Area = 1.992 ac Runoff Volume = 0.582 af Average Runoff Depth = 3.50" 31.17% Pervious = 0.621 ac 68.83% Impervious = 1.371 ac Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 54HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Existing Property [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =4.18 cfs @ 11.89 hrs, Volume=0.199 af, Depth= 3.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 15,246 96 Gravel surface, HSG D 9,322 98 Paved parking, HSG D 1,960 98 Roofs, HSG D 3,093 84 50-75% Grass cover, Fair, HSG D 29,621 96 Weighted Average 18,339 61.91% Pervious Area 11,282 38.09% Impervious Area Subcatchment 1S: Existing Property Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=29,621 sf Runoff Volume=0.199 af Runoff Depth=3.50" Tc=0.0 min CN=96 4.18 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 55HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =1.20 cfs @ 11.89 hrs, Volume=0.059 af, Depth= 3.62" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 2S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=8,454 sf Runoff Volume=0.059 af Runoff Depth=3.62" Tc=0.0 min CN=96 1.20 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 56HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.47 cfs @ 11.89 hrs, Volume=0.022 af, Depth= 3.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 5S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(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 25-Yr Rainfall=4.00" Runoff Area=3,595 sf Runoff Volume=0.022 af Runoff Depth=3.26" Tc=0.0 min CN=93 0.47 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 57HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 6S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =1.35 cfs @ 11.89 hrs, Volume=0.066 af, Depth= 3.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 6S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=9,402 sf Runoff Volume=0.066 af Runoff Depth=3.65" Tc=0.0 min CN=97 1.35 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 58HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 12S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.94 cfs @ 11.89 hrs, Volume=0.045 af, Depth= 3.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 12S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=7,131 sf Runoff Volume=0.045 af Runoff Depth=3.29" Tc=0.0 min CN=93 0.94 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 59HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 16S: DA1 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =1.20 cfs @ 11.89 hrs, Volume=0.059 af, Depth= 3.62" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 7,749 98 Paved parking, HSG D 705 80 >75% Grass cover, Good, HSG D 8,454 96 Weighted Average 705 8.34% Pervious Area 7,749 91.66% Impervious Area Subcatchment 16S: DA1 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=8,454 sf Runoff Volume=0.059 af Runoff Depth=3.62" Tc=0.0 min CN=96 1.20 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 60HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 17S: DA4 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.47 cfs @ 11.89 hrs, Volume=0.022 af, Depth= 3.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 1,663 98 Paved parking, HSG D 1,052 80 >75% Grass cover, Good, HSG D 880 98 Roofs, HSG D 3,595 93 Weighted Average 1,052 29.26% Pervious Area 2,543 70.74% Impervious Area Subcatchment 17S: DA4 Runoff Hydrograph Time (hours)727068666462605856545250484644424038363432302826242220181614121086420Flow(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 25-Yr Rainfall=4.00" Runoff Area=3,595 sf Runoff Volume=0.022 af Runoff Depth=3.26" Tc=0.0 min CN=93 0.47 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 61HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 18S: DA2 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =1.35 cfs @ 11.89 hrs, Volume=0.066 af, Depth= 3.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 8,778 98 Paved parking, HSG D 624 80 >75% Grass cover, Good, HSG D 9,402 97 Weighted Average 624 6.64% Pervious Area 8,778 93.36% Impervious Area Subcatchment 18S: DA2 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=9,402 sf Runoff Volume=0.066 af Runoff Depth=3.65" Tc=0.0 min CN=97 1.35 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 62HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Subcatchment 19S: DA3 [46] Hint: Tc=0 (Instant runoff peak depends on dt) Runoff =0.94 cfs @ 11.89 hrs, Volume=0.045 af, Depth= 3.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-Q, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Yr Rainfall=4.00" Area (sf) CN Description 4,050 98 Roofs, HSG D 1,105 98 Unconnected pavement, HSG D 1,976 80 >75% Grass cover, Good, HSG D 7,131 93 Weighted Average 1,976 27.71% Pervious Area 5,155 72.29% Impervious Area 1,105 21.44% Unconnected Subcatchment 19S: DA3 Runoff Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Type II 24-hr 25-Yr Rainfall=4.00" Runoff Area=7,131 sf Runoff Volume=0.045 af Runoff Depth=3.29" Tc=0.0 min CN=93 0.94 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 63HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 11R: PIPE 1 [52] Hint: Inlet/Outlet conditions not evaluated Inflow Area =0.410 ac, 92.56% Impervious, Inflow Depth = 3.64" for 25-Yr event Inflow =2.55 cfs @ 11.89 hrs, Volume=0.124 af Outflow =2.38 cfs @ 11.90 hrs, Volume=0.124 af, Atten= 7%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.46 fps, Min. Travel Time= 0.7 min Avg. Velocity = 0.74 fps, Avg. Travel Time= 2.2 min Peak Storage= 97 cf @ 11.89 hrs Average Depth at Peak Storage= 0.95' Bank-Full Depth= 1.25' Flow Area= 1.2 sf, Capacity= 2.66 cfs 15.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 97.0' Slope= 0.0040 '/' Inlet Invert= 205.98', Outlet Invert= 205.59' Reach 11R: PIPE 1 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)2 1 0 Inflow Area=0.410 ac Avg. Flow Depth=0.95' Max Vel=2.46 fps 15.0" Round Pipe n=0.020 L=97.0' S=0.0040 '/' Capacity=2.66 cfs 2.55 cfs 2.38 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 64HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Reach 12R: PIPE 2 [52] Hint: Inlet/Outlet conditions not evaluated [62] Hint: Exceeded Reach 11R OUTLET depth by 0.14' @ 12.00 hrs [79] Warning: Submerged Pond 10P Primary device # 1 INLET by 0.35' [79] Warning: Submerged Pond 15P Primary device # 1 INLET by 0.30' Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 3.30" for 25-Yr event Inflow =3.71 cfs @ 11.90 hrs, Volume=0.181 af Outflow =3.64 cfs @ 11.91 hrs, Volume=0.181 af, Atten= 2%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.74 fps, Min. Travel Time= 0.2 min Avg. Velocity = 0.79 fps, Avg. Travel Time= 0.7 min Peak Storage= 47 cf @ 11.90 hrs Average Depth at Peak Storage= 1.07' Bank-Full Depth= 1.50' Flow Area= 1.8 sf, Capacity= 4.32 cfs 18.0" Round Pipe n= 0.020 Corrugated PE, corrugated interior Length= 35.0' Slope= 0.0040 '/' Inlet Invert= 205.54', Outlet Invert= 205.40' Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 65HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Reach 12R: PIPE 2 Inflow Outflow Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=0.656 ac Avg. Flow Depth=1.07' Max Vel=2.74 fps 18.0" Round Pipe n=0.020 L=35.0' S=0.0040 '/' Capacity=4.32 cfs 3.71 cfs 3.64 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 66HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 3P: Offsite [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.680 ac, 38.09% Impervious, Inflow Depth = 3.50" for 25-Yr event Inflow =4.18 cfs @ 11.89 hrs, Volume=0.199 af Primary =4.18 cfs @ 11.89 hrs, Volume=0.199 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 3P: Offsite Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=0.680 ac4.18 cfs4.18 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 67HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 4P: OFFSITE [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 3.30" for 25-Yr event Inflow =3.64 cfs @ 11.91 hrs, Volume=0.181 af Primary =3.64 cfs @ 11.91 hrs, Volume=0.181 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 4P: OFFSITE Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=0.656 ac3.64 cfs3.64 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 68HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 5P: Filterra FTPD0608-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.194 ac, 91.66% Impervious, Inflow Depth = 3.62" for 25-Yr event Inflow =1.20 cfs @ 11.89 hrs, Volume=0.059 af Primary =1.20 cfs @ 11.89 hrs, Volume=0.059 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 5P: Filterra FTPD0608-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.194 ac1.20 cfs1.20 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 69HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 10P: Bioretention #2 Inflow Area =0.083 ac, 70.74% Impervious, Inflow Depth = 3.26" for 25-Yr event Inflow =0.47 cfs @ 11.89 hrs, Volume=0.022 af Outflow =0.45 cfs @ 11.90 hrs, Volume=0.020 af, Atten= 6%, Lag= 0.7 min Primary =0.45 cfs @ 11.90 hrs, Volume=0.020 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 209.62' @ 11.90 hrs Surf.Area= 323 sf Storage= 154 cf Plug-Flow detention time= 106.5 min calculated for 0.020 af (88% of inflow) Center-of-Mass det. time= 47.2 min ( 804.3 - 757.2 ) Volume Invert Avail.Storage Storage Description #1 209.00'295 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.00 179 109.0 0 0 179 210.00 430 134.8 295 295 694 Device Routing Invert Outlet Devices #1 Primary 206.25'12.0" Round Culvert L= 17.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.25' / 206.00' S= 0.0147 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 209.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.45 cfs @ 11.90 hrs HW=209.62' (Free Discharge) 1=Culvert (Passes 0.45 cfs of 5.06 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.45 cfs @ 1.15 fps) Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 70HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 10P: Bioretention #2 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.083 ac Peak Elev=209.62' Storage=154 cf 0.47 cfs 0.45 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 71HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 14P: Filterra FTPD0610-G [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.216 ac, 93.36% Impervious, Inflow Depth = 3.65" for 25-Yr event Inflow =1.35 cfs @ 11.89 hrs, Volume=0.066 af Primary =1.35 cfs @ 11.89 hrs, Volume=0.066 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 14P: Filterra FTPD0610-G Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.216 ac1.35 cfs1.35 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 72HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 15P: Bioretention #1 Inflow Area =0.164 ac, 72.29% Impervious, Inflow Depth = 3.29" for 25-Yr event Inflow =0.94 cfs @ 11.89 hrs, Volume=0.045 af Outflow =0.89 cfs @ 11.90 hrs, Volume=0.037 af, Atten= 6%, Lag= 0.8 min Primary =0.89 cfs @ 11.90 hrs, Volume=0.037 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 210.70' @ 11.90 hrs Surf.Area= 442 sf Storage= 444 cf Plug-Flow detention time= 139.2 min calculated for 0.037 af (81% of inflow) Center-of-Mass det. time= 60.5 min ( 816.7 - 756.3 ) Volume Invert Avail.Storage Storage Description #1 209.25'589 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim.Inc.Store Cum.Store Wet.Area (feet)(sq-ft)(feet)(cubic-feet)(cubic-feet)(sq-ft) 209.25 183 81.3 0 0 183 210.00 312 90.8 183 183 328 211.00 506 103.6 405 589 549 Device Routing Invert Outlet Devices #1 Primary 206.30'12.0" Round Culvert L= 58.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 206.30' / 205.90' S= 0.0069 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior, Flow Area= 0.79 sf #2 Device 1 210.50'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.88 cfs @ 11.90 hrs HW=210.69' (Free Discharge) 1=Culvert (Passes 0.88 cfs of 4.93 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.88 cfs @ 1.44 fps) Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 73HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Pond 15P: Bioretention #1 Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)1 0 Inflow Area=0.164 ac Peak Elev=210.70' Storage=444 cf 0.94 cfs 0.89 cfs Type II 24-hr 25-Yr Rainfall=4.00"19-202 Stormwater Printed 6/18/2020Prepared by Trudell Consulting Engineers Page 74HydroCAD® 10.00-12 s/n 02145 © 2014 HydroCAD Software Solutions LLC Summary for Pond 20P: Offsite Pre-Routed [40] Hint: Not Described (Outflow=Inflow) Inflow Area =0.656 ac, 84.76% Impervious, Inflow Depth = 3.50" for 25-Yr event Inflow =3.97 cfs @ 11.89 hrs, Volume=0.192 af Primary =3.97 cfs @ 11.89 hrs, Volume=0.192 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Pond 20P: Offsite Pre-Routed Inflow Primary Hydrograph Time (hours) 727068666462605856545250484644424038363432302826242220181614121086420Flow(cfs)4 3 2 1 0 Inflow Area=0.656 ac3.97 cfs3.97 cfs Vermont Department of Environmental Conservation Agency of Natural Resources Watershed Management Division One National Life Drive, Main Bldg., 2nd Floor Montpelier, VT 05620 6/19/18 Contech Engineered Solutions, LLC 9025 Centre Pointe Drive, Suite 400 West Chester, OH 45069 Attn: Derek Berg Dear Mr. Berg: The Stormwater Program has reviewed the Filterra® Bioretention System as an alternative stormwater treatment practice through the evaluation process in Section 4.4.1 of the 2017 Vermont Stormwater Management Manual (VSMM). Based on our review, we believe that Contech Engineered Solutions, LLC has provided the Stormwater Program with testing data showing that the system provides total phosphorus and total suspended solids removal efficiency sufficient to meet or exceed the standards in the Vermont Stormwater Management Manual as a stand-alone Tier 2 Practice if not designed to infiltrate, and as a Tier 1 Practice if the boxless Bioscape model is used for infiltration. Please be advised that this letter serves as preliminary approval and does not constitute a final act or decision of the Secretary. Final approval of the use of the Filterra® Bioretention System, or other alternative practice, is project specific and is necessarily done through the issuance of an operational stormwater permit, until such time that the Vermont Stormwater Management Manual is formally revised to include the practice. In developing permit conditions for any project relying on the Filterra® Bioretention System, the Stormwater Program is likely to include the following permit conditions and application requirements: 1.) The Filterra® Bioretention System must be designed, assembled, installed, operated, and maintained according to the specifications of Contech Engineered Solutions, Inc. 2.) The system must be designed to accommodate 100% treatment of the requisite water quality volume through sizing for the peak rate of the water quality storm without bypass, or otherwise shall be volumetrically sized to accommodate the entire applicable water quality volume. As part of this preliminary approval, the product will be listed on the Vermont Department of Environmental Conservation’s Alternative Practices website at http://dec.vermont.gov/watershed/stormwater/permit-information-applications-fees/Alt-STPs. Preliminary Approval: Filterra® Bioretention System Until such a time that the practice is incorporated into the VSMM through rulemaking, projects utilizing the practice that are subject to operational stormwater permitting require an individual permit application. If local jurisdictions or other parties request a copy of a letter from VT DEC verifying preliminary practice approval, please use this letter for that purpose. Thank you for your interest in providing alternatives to the stormwater design community in Vermont. If you have any questions concerning this preliminary approval, please contact the Stormwater Program. Sincerely, William Wilson, Environmental Analyst Vermont DEC – Stormwater Program AAPLAN VIEWSECTION A-A(STANDARD DEPTH SHOWN)21" FILTERRA MEDIA, TYPPROVIDED BY CONTECH6" UNDERDRAINSTONE LAYER, TYPPROVIDED BY CONTECH3" MULCH LAYER, TYPPROVIDED BY CONTECHVAULT LENGTH6" (STD)12" (DEEP)4'-1" (STD)4'-7" (DEEP)7"Ø CLEANOUTTREE GRATEVAULT WIDTHOUTLET PIPENOT BY CONTECH(LOCATION VARIES)2"Ø IRRIGATION PORT(TYP 3 PLACES)UNDERDRAIN*ALT CURBINLET LOC2'-0"MINMEDIA BAYPLANT PROVIDED BY CONTECHELEVATED GRATE AND FRAME(CAST INTO CAST-IN PLACERISER NOT BY CONTECH)CLEAN OUT FRAME ANDCOVER CAST INTO TOP SLABW/ (3) 2" RISER RINGS2"Ø IRRIGATION PORT(TYP 3 PLACES)FLOWKITOUTLET PIPENOT BY CONTECH(LOCATION VARIES)*INLET PIPENOT BY CONTECH(LOCATION VARIES)OUTLETACCESSGRATEINLETTOP SLAB*INLET PIPENOT BY CONTECH(LOCATION VARIES) 2'-7"INLET BAYPERMANENTSETTLINGPOOL ELEV.ENERGY DISSIPATION ROCKSCURB TYP.(NOT BY CONTECH)6" TYP TRANSFER OPENING4" x 15" ON 4' WIDE VAULTS4" x 20" ON 6'-8' WIDE VAULTSALTERNATE ORIENTATIONFTPD-G STANDARD HEIGHT CONFIGURATIONDESIGNATION(OPTIONS: -P)AVAILABILITYMEDIABAY SIZEVAULTSIZE(W x L)WEIRLENGTH/MAX CURBOPENING*MAXBYPASSFLOW(CFS)GRATEINLET/OUTLETACCESSSIZETREEGRATEQTY &SIZEFTPD0404-GN/A CA4 x 44 x 61'-8"1.412"SQ/12"Ø(1) 2.5' x 2.5'FTPD04045-GCA ONLY4 x 4.54 x 6.51'-8"1.412"SQ/12"Ø(1) 2.5' x 2.5'FTPD0406-GN/A MID-ATL4 x 64 x 81'-8"1.412"SQ/12"Ø(1) 3' x 3'FTPD045058-GMID-ATL ONLY4.5 x 5.834.5 x 7.831'-8"1.412"SQ/12"Ø(1) 3' x 3'FTPD0604-GALL6 x 46 x 61'-8"1.424"SQ/12"Ø(1) 2.5' x 2.5'FTPD0606-GALL6 x 66 x 81'-8"1.424"SQ/12"Ø(1) 3' x 3'FTPD0608-GALL6 x 86 x 101'-8"1.424"SQ/12"Ø(1) 4' x 4'FTPD0610-GALL6 x 106 x 121'-8"1.424"SQ/12"Ø(1) 4' x 4'FTPD0710-GALL7 x 107 x 132'-6"2.124"SQ/24"Ø(1) 4' x 4'FTPD08105-GALL8 x 10.58 x 143'-0"2.524"SQ/24"Ø(1) 4' x 4'FTPD08125-GALL8 x 12.58 x 163'-0"2.524"SQ/24"Ø(2) 4' x 4'N/A = NOT AVAILABLE800-338-1122 513-645-7000 513-645-7993 FAX9025 Centre Pointe Dr., Suite 400, West Chester, OH 45069I:\STORMWATER\COMMOPS\54 FILTERRA\40 STANDARD DRAWINGS\FTPD - FILTERRA PEAK DIVERSION\FTPD-G\LAYOUT DETAILS\DWG\FTPD-G - FILTERRA PEAK DIVERSION - GRATE CONFIG DTL.DWG 10/4/2018 11:11 AM FILTERRA PEAK DIVERSION - GRATE (FTPD-G)CONFIGURATION DETAILwww.ContechES.comTHIS PRODUCT MAY BE PROTECTED BY ONE OR MORE OFTHE FOLLOWING U.S. PATENTS: 6,277,274; 6,569,321;7,625,485; 7,425,261 ; 7,833,412; RELATED FORE IGN PATENTS.®INTERNAL PIPE CONFIGURATION MAY VARYDEPENDING UPON OUTLET LOCATION.The design and information shown on this drawing is provided as a service to the project owner, engineer and contractor by Contech Engineered Solutions LLC or one of its affiliated companies ("Contech"). Neither this drawing, nor any part thereof, may be used, reproduced or modified in any mannerwithout the prior written consent of Contech. Failure to comply is done at the user's own risk and Contech expressly disclaims any liabi lity or responsibility for such use. If discrepancies between the supplied information upon which the drawing is based and actual field conditions are encountered as sitework progresses, these discrepancies must be reported to Contech immediately for re-evaluation of the design. Contech accepts no liab ility for designs based on missing, incomplete or inaccurate information supp lied by others.FTPD-GD DEEP OPTION CONFIGURATIONDESIGNATION(OPTIONS: -P)AVAILABILITYMEDIABAY SIZEVAULTSIZE(W x L)WEIRLENGTH/MAX CURBOPENING*MAXBYPASSFLOW(CFS)GRATEINLET/OUTLETACCESSSIZETREEGRATEQTY &SIZEFTPD0404-GDN/A CA4 x 44 x 61'-8"4.612"SQ/12"Ø(1) 2.5' x 2.5'FTPD04045-GDCA ONLY4 x 4.54 x 6.51'-8"4.612"SQ/12"Ø(1) 2.5' x 2.5'FTPD0406-GDN/A MID-ATL4 x 64 x 81'-8"4.612"SQ/12"Ø(1) 3' x 3'FTPD045058-GDMID-ATL ONLY4.5 x 5.834.5 x 7.831'-8"4.612"SQ/12"Ø(1) 3' x 3'FTPD0604-GDALL6 x 46 x 61'-8"4.624"SQ/12"Ø(1) 2.5' x 2.5'FTPD0606-GDALL6 x 66 x 81'-8"4.624"SQ/12"Ø(1) 3' x 3'FTPD0608-GDALL6 x 86 x 101'-8"4.624"SQ/12"Ø(1) 4' x 4'FTPD0610-GDALL6 x 106 x 121'-8"4.624"SQ/12"Ø(1) 4' x 4'FTPD0710-GDALL7 x 107 x 132'-6"6.824"SQ/24"Ø(1) 4' x 4'FTPD08105-GDALL8 x 10.58 x 143'-0"8.224"SQ/24"Ø(1) 4' x 4'FTPD08125-GDALL8 x 12.58 x 163'-0"8.224"SQ/24"Ø(2) 4' x 4'N/A = NOT AVAILABLE*IF REQUIRED*IF REQUIRED*MAX BYPASS FLOW IS INTERNAL WEIR FLOW . SITE SPECIFIC ANALYSIS IS REQUIRED TO DETERMINE GRATE INLET FLOW CAPACITY Size Max Area (ac) Max Area (sf)CN Tc (min) WQ Inflow (cfs) Outflow (cfs) 4x4 0.064 2,792 98 6 0.08 0.05 4x6 0.096 4,188 98 6 0.13 0.08 4x8 0.128 5,584 98 6 0.17 0.10 6x6 0.144 6,282 98 6 0.19 0.12 6x8 0.192 8,376 98 6 0.25 0.16 6x10 0.240 10,470 98 6 0.31 0.19 6x12 0.288 12,564 98 6 0.38 0.23 7x13 0.365 15,879 98 6 0.48 0.29 1.0" Type II Rainfall Contech Filterra Vermont Sizing Quick Reference Table Vermont Department of Environmental Conservation Agency of Natural Resources Watershed Management Division Davis Building, Third Floor One National Life Drive (phone) 802-828-1535 Montpelier, VT 05620-3522 To preserve, enhance, restore, and conserve Vermont's natural resources, and protect human health, for the benefit of this and future generations. February 07, 2020 Anoka Conservation District 1318 McKay Dr. NE, Suite 300 Ham Lake, MN 55304 Attn: Mitch Haustein RE: Rain Guardian Bunker and Turret Alternative Stormwater Pre-Treatment Practice - Request for Approval Dear Mr. Haustein: The Stormwater Program has reviewed the Anoka Conservation Districts Rain Guardian Bunker and Turret as alternative stormwater pretreatment practices through the evaluation process in Section 4.4.1 of the 2017 Vermont Stormwater Management Manual (VSMM). Based on our review, we believe that the University of Minnesota St. Anthony Falls Laboratory study has provided the Stormwater Program with testing data showing that the systems provide a minimum 50% total suspended solids (TSS) removal efficiency in conformance with the 2017 VSMM. Please be advised that this letter serves as preliminary approval and does not constitute a final act or decision of the Secretary. Final approval of the use of Rain Guardian Bunker or Turret, or other alternative practice, is project specific and is necessarily done through the issuance of an operational stormwater permit, until such time that the Vermont Stormwater Management Manual is formally revised to include the practice. In developing permit conditions for any project relying on the Rain Guardian Turret or Bunker, the Stormwater Program is likely to include the following permit conditions and application requirements: 1) The Rain Guardian Bunker and Turret must be designed, assembled, installed, operated, and maintained according to the specifications of Rain Guardian. 2) The system must be designed to accommodate the required Qwq, as a flow through practice. As part of this preliminary approval, the product will be listed on the Vermont Department of Environmental Conservation’s Alternative Practices website at http://dec.vermont.gov/watershed/stormwater/permit-information-applications-fees/Alt-STPs. If local jurisdictions or other parties request a copy of a letter from VT DEC verifying preliminary practice approval, please use this letter for that purpose. February 07, 2020 Preliminary Approval: Rain Guardian Bunker and Turret 2 Thank you for your interest in providing alternatives to the stormwater design community in Vermont. If you have any questions concerning this preliminary approval, please contact the Stormwater Program. Sincerely, Winn Wilson, Environmental Analyst Vermont DEC – Stormwater Program 1318 MCKAY DR. NE, SUITE 300 HAM LAKE, MN 55304 (763) 434-2030 (M-F 8:00-4:30) WWW.ANOKASWCD.ORG PLAN VIEW TURRET TYPICAL DETAIL CROSS-SECTION VIEW U.S. PATENT NO. 8,501,016 U.S. PATENT NO. 8,501,016 COMPONENT VIEW U.S. PATENT NO. 8,501,016 SPECIFICATIONS U.S. PATENT NO. 8,501,016 1. STEEL REINFORCED, COLD JOINT SECURED MONOLITHIC CONCRETE STRUCTURE (1,030 LBS). 2. CONCRETE SHALL HAVE A MINIMUM COMPRESSIVE STRENGTH OF 4,000 PSI AT 28 DAYS. CONCRETE AIR ENTRAINED (4% TO 8% BY VOLUME). 3. MANUFACTURED AND DESIGNED TO ASTM C858. 4. THREE-POINT PICK USING RECESSED LIFTING POCKETS WITH A STANDARD HOOK. 5. SOIL UNDER BASE TO BE COMPACTED TO 95% STANDARD PROCTOR. 6. TWO-PIECE LIGHT DUTY GALVANIZED GRATE (34.5 LBS/PIECE) FOR 541 LB CONCENTRATED LOAD OR 309 LB/SQ FT UNIFORM LOAD. 7. TWO-PIECE HEAVY DUTY GALVANIZED GRATE (77.5 LBS/PIECE) FOR 2,456 LB CONCENTRATED LOAD OR 1,404 LB/SQ FT UNIFORM LOAD. 8. USE EXPANSION JOINT MATERIAL BETWEEN TURRET AND BIORETENTION INLET MANUFACTURED BY