Southtowns Record

PB Agenda Packet 8.13.2026

Government
Town of West Seneca
Board
Planning Board
Meeting
Aug 13, 2026, 6:00 p.m.
Posted by publisher
Jul 28, 2026
Kind
Agenda packet
Topics
Water, sewer and drainage, Roads and traffic, Housing, Zoning and land use, Parks and recreation, Budget and taxes, Public safety

Original document

Same meeting

Text · page 786 of 1174

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24-4113 WEST SENECA EXCAHNG NY-WestSeneca_NOAA14 24-hr S1 100-yr Rainfall=5.20"
Prepared by Carmina Wood Design  Printed 7/13/2026
HydroCAD® 10.20-7a s/n 05019 © 2025 HydroCAD Software Solutions LLC  Page 51

  Summary for Subcatchment 1S: Proposed - West

[47] Hint: Peak is 1492% of capacity of segment #2

Runoff  =  140.14 cfs @ 12.02 hrs, Volume=  7.035 af, Depth= 4.39"
  Routed to Pond 18P : POND

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-150.00 hrs, dt= 0.01 hrs
NY-WestSeneca_NOAA14 24-hr S1 100-yr Rainfall=5.20"

  Area (ac)  CN  Description
  5.060  80  >75% Grass cover, Good, HSG D
  4.110  98  Roofs, HSG D
  10.040  98  Paved parking, HSG D
  19.210  93  Weighted Average
  5.060  26.34% Pervious Area
  14.150  73.66% Impervious Area

  Tc Length Slope Velocity Capacity Description
  (min) (feet)  (ft/ft) (ft/sec) (cfs)
  1.8  100 0.0100  0.92  Sheet Flow, pavement
  Smooth surfaces n= 0.011 P2= 2.50"
  3.0  950 0.0080  5.32 9.40 Pipe Channel, 18" PIPE
  18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38'
  n= 0.013 Corrugated PE, smooth interior
  4.8 1,050 Total

  Subcatchment 1S: Proposed - West
  Hydrograph

  Runoff
  150  140.14 cfs
  140  NY-WestSeneca_NOAA14 24-hr S1 100-yr
  Rainfall=5.20"
  130
  Runoff Area=19.210 ac
  120  Runoff Volume=7.035 af
  110  Runoff Depth=4.39"
  Flow Length=1,050'
  100
  Tc=4.8 min
  90  CN=93
  Flow (cfs)

  80
  70
  60
  50

  40
  30

  20
  10
  0
  0  10  20  30  40  50  60  70  80  90  100  110  120  130  140  150
  Time (hours)

  Page 786 of 1174