Southtowns Record

5A.-ENGINEER'S REPORT

Government
Town of Aurora
Board
Town Board
Meeting
Feb 4, 2026
Kind
Other
Topics
Water, sewer and drainage, Zoning and land use, Public safety

Original document

Same meeting

Text · page 202 of 351

Read the whole document on one page (all 351 pages, each with its own heading)

WNY-2500056.00_HydroCAD  extreme_precip_tables_output (29) 24-hr S1 25-yr Rainfall=3.85"
Prepared by Greenman-Pedersen, Inc  Printed 12/18/2025
HydroCAD® 10.20-7a s/n 04560 © 2025 HydroCAD Software Solutions LLC  Page 127

  Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 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 ATO: Area to Offsite  Runoff Area=0.190 ac 0.00% Impervious Runoff Depth>1.91"
  Flow Length=60' Slope=0.0050 '/' Tc=30.0 min CN=80 Runoff=0.28 cfs 0.030 af

Subcatchment DA 1: Drainage Area 1  Runoff Area=0.060 ac 100.00% Impervious Runoff Depth>3.62"
  Flow Length=80' Slope=0.0100 '/' Tc=1.6 min CN=98 Runoff=0.35 cfs 0.018 af

Subcatchment DA 2: Drainage Area 2  Runoff Area=0.010 ac 100.00% Impervious Runoff Depth>3.62"
  Flow Length=35' Slope=0.0100 '/' Tc=0.8 min CN=98 Runoff=0.06 cfs 0.003 af

Subcatchment DA 3: Drainage Area 3  Runoff Area=0.150 ac 93.33% Impervious Runoff Depth>3.50"
  Flow Length=75' Slope=0.0100 '/' Tc=7.2 min CN=97 Runoff=0.70 cfs 0.044 af

Subcatchment DA 4: Drainage Area 4  Runoff Area=0.080 ac 87.50% Impervious Runoff Depth>3.39"
  Flow Length=20' Slope=0.0100 '/' Tc=6.3 min CN=96 Runoff=0.38 cfs 0.023 af

Subcatchment DA 5: Drainage Area 5  Runoff Area=0.050 ac 100.00% Impervious Runoff Depth>3.62"
  Flow Length=60' Slope=0.0050 '/' Tc=1.7 min CN=98 Runoff=0.29 cfs 0.015 af

Subcatchment DA 6: Drainage Area 6  Runoff Area=0.150 ac 40.00% Impervious Runoff Depth>2.49"
  Flow Length=40' Slope=0.0045 '/' Tc=15.0 min CN=87 Runoff=0.41 cfs 0.031 af

Pond EX RCVR: EX RCVR  Peak Elev=900.32' Inflow=1.14 cfs 0.123 af
  12.0" Round Culvert n=0.013 L=121.0' S=0.0031 '/' Outflow=1.14 cfs 0.123 af

Pond RCVR 1: RCVR 1  Peak Elev=901.27' Inflow=0.62 cfs 0.076 af
  8.0" Round Culvert n=0.013 L=59.0' S=0.0041 '/' Outflow=0.62 cfs 0.076 af

Pond RCVR 2: RCVR 2  Peak Elev=901.12' Inflow=1.14 cfs 0.123 af
  8.0" Round Culvert n=0.013 L=72.0' S=0.0100 '/' Outflow=1.14 cfs 0.123 af

Pond RCVR 3: RCVR 3  Peak Elev=901.28' Inflow=0.70 cfs 0.044 af
  8.0" Round Culvert n=0.013 L=39.0' S=0.0041 '/' Outflow=0.70 cfs 0.044 af