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 205 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 1-yr Rainfall=1.82"
Prepared by Labella Associates  Printed 4/20/2026
HydroCAD® 10.20-7a s/n 09581 © 2025 HydroCAD Software Solutions LLC  Page 5

  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=0.72"
  Tc=6.0 min CN=86 Runoff=0.72 cfs 0.038 af

Subcatchment PS-2:  Runoff Area=72,316 sf 88.61% Impervious Runoff Depth=1.40"
  Tc=6.0 min CN=96 Runoff=3.74 cfs 0.194 af

Subcatchment PS-3:  Runoff Area=28,267 sf 33.49% Impervious Runoff Depth=0.72"
  Tc=6.0 min CN=86 Runoff=0.74 cfs 0.039 af

Subcatchment PS-4:  Runoff Area=29,485 sf 70.98% Impervious Runoff Depth=1.15"
  Tc=6.0 min CN=93 Runoff=1.28 cfs 0.065 af

Subcatchment PS-5:  Runoff Area=18,756 sf 100.00% Impervious Runoff Depth=1.60"
  Tc=6.0 min CN=98 Runoff=1.06 cfs 0.057 af

Subcatchment PS-6:  Runoff Area=6,622 sf 100.00% Impervious Runoff Depth=1.60"
  Tc=6.0 min CN=98 Runoff=0.37 cfs 0.020 af

Subcatchment PS-7:  Runoff Area=245,856 sf 0.00% Impervious Runoff Depth=0.46"
  Flow Length=391' Tc=14.0 min CN=80 Runoff=2.49 cfs 0.215 af

Subcatchment PS-8:  Runoff Area=53,474 sf 0.00% Impervious Runoff Depth=0.46"
  Flow Length=821' Slope=0.0100 '/' Tc=25.7 min CN=80 Runoff=0.40 cfs 0.047 af

Reach DP-1: Design Point  Inflow=4.12 cfs 0.674 af
  Outflow=4.12 cfs 0.674 af

Pond BIO-1: Filtration Bioretention  Peak Elev=598.98' Storage=994 cf Inflow=0.72 cfs 0.038 af
Primary=0.02 cfs 0.038 af Secondary=0.00 cfs 0.000 af Tertiary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.038 af

Pond BIO-2: Filtration Bioretention  Peak Elev=596.95' Storage=1,010 cf Inflow=0.74 cfs 0.039 af
Primary=0.02 cfs 0.039 af Secondary=0.00 cfs 0.000 af Tertiary=0.00 cfs 0.000 af Outflow=0.02 cfs 0.039 af

Pond BIO-3: Filtration Bioretention  Peak Elev=595.92' Storage=1,729 cf Inflow=1.28 cfs 0.065 af
Primary=0.04 cfs 0.065 af Secondary=0.00 cfs 0.000 af Tertiary=0.00 cfs 0.000 af Outflow=0.04 cfs 0.065 af

Pond CH-1: Chambers  Peak Elev=592.38' Storage=0.079 af Inflow=4.80 cfs 0.251 af
  8.0" Round Culvert n=0.013 L=25.0' S=0.0100 '/' Outflow=1.18 cfs 0.251 af

  Total Runoff Area = 11.074 ac Runoff Volume = 0.674 af Average Runoff Depth = 0.73"
  73.21% Pervious = 8.107 ac 26.79% Impervious = 2.967 ac

  Page 205 of 1493