Southtowns Record

PBA07.09.2026packet

Government
Town of West Seneca
Board
Planning Board
Meeting
Jul 9, 2026, 6:00 p.m.
Posted by publisher
Jul 9, 2026
Kind
Agenda packet
Topics
Water, sewer and drainage, Housing, Zoning and land use, Roads and traffic, Parks and recreation, Budget and taxes, Public safety

Original document

Same meeting

Text · page 224 of 1493

Read the whole document on one page (all 1493 pages, each with its own heading)

E_App E_Post-Development Model  NY-West Seneca 24-hr S1 10-yr Rainfall=3.14"
Prepared by Labella Associates  Printed 4/20/2026
HydroCAD® 10.20-7a s/n 09581 © 2025 HydroCAD Software Solutions LLC  Page 24

  Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points
  Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
  Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method

Subcatchment PS-1:  Runoff Area=27,596 sf 33.98% Impervious Runoff Depth=1.78"
  Tc=6.0 min CN=86 Runoff=1.71 cfs 0.094 af

Subcatchment PS-2:  Runoff Area=72,316 sf 88.61% Impervious Runoff Depth=2.69"
  Tc=6.0 min CN=96 Runoff=6.39 cfs 0.372 af

Subcatchment PS-3:  Runoff Area=28,267 sf 33.49% Impervious Runoff Depth=1.78"
  Tc=6.0 min CN=86 Runoff=1.75 cfs 0.096 af

Subcatchment PS-4:  Runoff Area=29,485 sf 70.98% Impervious Runoff Depth=2.39"
  Tc=6.0 min CN=93 Runoff=2.39 cfs 0.135 af

Subcatchment PS-5:  Runoff Area=18,756 sf 100.00% Impervious Runoff Depth=2.91"
  Tc=6.0 min CN=98 Runoff=1.72 cfs 0.104 af

Subcatchment PS-6:  Runoff Area=6,622 sf 100.00% Impervious Runoff Depth=2.91"
  Tc=6.0 min CN=98 Runoff=0.61 cfs 0.037 af

Subcatchment PS-7:  Runoff Area=245,856 sf 0.00% Impervious Runoff Depth=1.36"
  Flow Length=391' Tc=14.0 min CN=80 Runoff=8.08 cfs 0.638 af

Subcatchment PS-8:  Runoff Area=53,474 sf 0.00% Impervious Runoff Depth=1.36"
  Flow Length=821' Slope=0.0100 '/' Tc=25.7 min CN=80 Runoff=1.32 cfs 0.139 af

Reach DP-1: Design Point  Inflow=13.96 cfs 1.615 af
  Outflow=13.96 cfs 1.615 af

Pond BIO-1: Filtration Bioretention  Peak Elev=599.12' Storage=1,232 cf Inflow=1.71 cfs 0.094 af
Primary=0.02 cfs 0.045 af Secondary=1.10 cfs 0.049 af Tertiary=0.00 cfs 0.000 af Outflow=1.12 cfs 0.094 af

Pond BIO-2: Filtration Bioretention  Peak Elev=597.12' Storage=1,319 cf Inflow=1.75 cfs 0.096 af
Primary=0.02 cfs 0.048 af Secondary=1.04 cfs 0.048 af Tertiary=0.00 cfs 0.000 af Outflow=1.06 cfs 0.096 af

Pond BIO-3: Filtration Bioretention  Peak Elev=596.12' Storage=2,359 cf Inflow=2.39 cfs 0.135 af
Primary=0.04 cfs 0.084 af Secondary=1.03 cfs 0.050 af Tertiary=0.00 cfs 0.000 af Outflow=1.07 cfs 0.135 af

Pond CH-1: Chambers  Peak Elev=593.15' Storage=0.161 af Inflow=8.11 cfs 0.476 af
  8.0" Round Culvert n=0.013 L=25.0' S=0.0100 '/' Outflow=1.66 cfs 0.476 af

  Total Runoff Area = 11.074 ac Runoff Volume = 1.615 af Average Runoff Depth = 1.75"
  73.21% Pervious = 8.107 ac 26.79% Impervious = 2.967 ac

  Page 224 of 1493