Southtowns Record

PBA03.12.2026packet

Government
Town of West Seneca
Board
Planning Board
Meeting
Mar 12, 2026, 6:00 p.m.
Posted by publisher
Feb 25, 2026
Kind
Agenda packet
Topics
Water, sewer and drainage, Roads and traffic, Zoning and land use

Original document

Same meeting

Text · page 55 of 65

Read the whole document on one page (all 65 pages, each with its own heading)

25-4181 storm calcs - proposed  Type II 24-hr 100-Year Rainfall=5.23"
Prepared by Carmina Wood Design  Printed 2/11/2026
HydroCAD® 10.20-8a s/n 05019 © 2025 HydroCAD Software Solutions LLC  Page 25

  Time span=0.50-70.00 hrs, dt=0.04 hrs, 1739 points
  Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
  Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Subcatchment 2S: Proposed Site  Runoff Area=53,039 sf 53.36% Impervious Runoff Depth=4.10"
  Flow Length=368' Tc=7.4 min CN=90 Runoff=7.83 cfs 18,115 cf

Pond 3P: Underground Detention  Peak Elev=529.23' Storage=5,193 cf Inflow=7.83 cfs 18,115 cf
  8.0" Round Culvert n=0.013 L=24.0' S=0.0050 '/' Outflow=2.85 cfs 18,115 cf

  Total Runoff Area = 53,039 sf Runoff Volume = 18,115 cf Average Runoff Depth = 4.10"
  46.64% Pervious = 24,735 sf 53.36% Impervious = 28,304 sf

  Page 55 of 65