7.1 Pond Sizing HardcoverProject: Arbor Glen
Location: Chanhassen MN
Prepared for: Chanhassen
Prepared by: Sathre-Bergquist, Inc.
Date: June 4, 2015
Revised: November 17, 2015
Revised: May 16, 2017
Nurp Design Basin 1
P =1.1 "Storm
Aw =6.00 Acres
No. of Houses =18 Each
Ave. House Roof Area =2250 SF
No. of Driveways 18 Each
Ave. Driveway Area =340 SF
Area Of Street =21300 SF
Topology Area CN
Total Hardcover Area = 1.56 Acres 98
Grasscover = 4.44 Acres 70
Hardcover For Fi = 0.63 Acres (Streets & Drives)
CN =77
Fi = 0.10
PerviousCN = 74.85 74712
6226
S = 1000/CN - 10 = 3.36 0.23128815
R = (P-.2S)(P-.2S)/(P+.8S)
R = 0.05
V = RAw/12 =0.02 Acre-Feet (Required)
Ponding Dead Storage Volume Based on Plan Contours - 10:1 Bench (1.0') Then 3:1 Slope
Contour Area (sf) Area (Ac) Cummulative Storage(cf) (Acre-Feet)
0.00
896 Drawdown 4,000 0.09 4,000 4000 0.09
898 NWL 8,500 0.20 12,500 16500 0.38 (Provided)
900 12,600 0.29 21,100 33600 0.77 0.289
902 17,500 0.40 30,100 51200 1.18 0.402
904 HWL 22,800 0.52 40,300 70400 1.62
Dead Storage/Pond Surface Area =2.93 ft
45700
Surface area w/4:1 slope=3000 sqft
Average Mean Depth=5.50 ft