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Home My WebLink AboutSP-22-060 - Supplemental - 0224 0268 Market Street (20)1S Sub-area 3PCB STMH Routing Diagram for Market St pipe Prepared by The Snyder Group, Inc., Printed 12/5/2022 HydroCAD® 10.00-26 s/n 05471 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link See Stormwater Narrative for summary of drainage areas to existing STMH / 18" PE pipe across Market Street. From Narrative: 1.38 acres total impervious 1.66 acres total drainage area Market St pipe Printed 12/5/2022Prepared by The Snyder Group, Inc. Page 2HydroCAD® 10.00-26 s/n 05471 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 1.660 92 Post development CN (1S) 1.660 92 TOTAL AREA Notes: modified CN used Market St pipe Printed 12/5/2022Prepared by The Snyder Group, Inc. Page 5HydroCAD® 10.00-26 s/n 05471 © 2020 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) 13P 305.92 303.07 100.0 0.0285 0.013 18.0 0.0 0.0 record data used for 18" PE pipe across Market Street (differs from City Hall design plans) Type II 24-hr 25 year Rainfall=3.84"Market St pipe Printed 12/5/2022Prepared by The Snyder Group, Inc. Page 6HydroCAD® 10.00-26 s/n 05471 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=1.660 ac 0.00% Impervious Runoff Depth>2.78"Subcatchment 1S: Sub-area Tc=2.6 min CN=92 Runoff=8.78 cfs 0.385 af Peak Elev=308.34' Inflow=8.78 cfs 0.385 afPond 3P: STMH 18.0" Round Culvert n=0.013 L=100.0' S=0.0285 '/' Outflow=8.78 cfs 0.385 af Total Runoff Area = 1.660 ac Runoff Volume = 0.385 af Average Runoff Depth = 2.78" 100.00% Pervious = 1.660 ac 0.00% Impervious = 0.000 ac Tc calculated using VSMM workbook / watershed lag method Type II 24-hr 25 year Rainfall=3.84"Market St pipe Printed 12/5/2022Prepared by The Snyder Group, Inc. Page 7HydroCAD® 10.00-26 s/n 05471 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Sub-area Data taken from VSMM workbook [49] Hint: Tc<2dt may require smaller dt Runoff =8.78 cfs @ 11.93 hrs, Volume=0.385 af, Depth> 2.78" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25 year Rainfall=3.84" Area (ac) CN Description *1.660 92 Post development CN 1.660 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 2.6 Direct Entry, Watershed Lag Subcatchment 1S: Sub-area Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)9 8 7 6 5 4 3 2 1 0 Type II 24-hr 25 year Rainfall=3.84" Runoff Area=1.660 ac Runoff Volume=0.385 af Runoff Depth>2.78" Tc=2.6 min CN=92 8.78 cfs Type II 24-hr 25 year Rainfall=3.84"Market St pipe Printed 12/5/2022Prepared by The Snyder Group, Inc. Page 8HydroCAD® 10.00-26 s/n 05471 © 2020 HydroCAD Software Solutions LLC Summary for Pond 3P: STMH flood elevation = STMH rim elevation [82] Warning: Early inflow requires earlier time span Inflow Area =1.660 ac, 0.00% Impervious, Inflow Depth > 2.78" for 25 year event Inflow =8.78 cfs @ 11.93 hrs, Volume=0.385 af Outflow =8.78 cfs @ 11.93 hrs, Volume=0.385 af, Atten= 0%, Lag= 0.0 min Primary =8.78 cfs @ 11.93 hrs, Volume=0.385 af Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 308.34' @ 11.93 hrs Flood Elev= 315.15' Device Routing Invert Outlet Devices #1 Primary 305.92'18.0" Round Culvert L= 100.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 305.92' / 303.07' S= 0.0285 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf Primary OutFlow Max=8.31 cfs @ 11.93 hrs HW=308.20' (Free Discharge) 1=Culvert (Inlet Controls 8.31 cfs @ 4.70 fps) Pond 3P: STMH Inflow Primary Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)9 8 7 6 5 4 3 2 1 0 Inflow Area=1.660 ac Peak Elev=308.34' 18.0" Round Culvert n=0.013 L=100.0' S=0.0285 '/' 8.78 cfs8.78 cfs peak ponding elevation = 308.34' 18" PE outlet invert = 305.92' for 25 year storm, ponding depth = 2.42' HW / D = 1.6 (STMH rim elevation)