Stout Landing Subdivision - 1283-POND 1 ROUTING (10yr storm)

4D Site Solutions, Inc.
DESIGN REQUIREMENTS:
A. Post development runoff <= Predevelopment
Stout Landing - Detention Pond #1 Pre-Development Runoff - 10-yr
Drainage Area, (DA) = 73.60 acres
Intensity, (I) = 6.31 inches/hr
Composite Runoff Coefficient, (C) => 0.30
Maximum Release Rate, (Q10) => 139.32 cfs
Stout Landing - Detention Pond #1 Post-Development Runoff - 10-yr
Drainage Area, (DA) = 73.60 acres
Intensity, (I) = 6.31 inches/hr
Composite Runoff Coefficient, (C) => 0.59
Peak Release Rate, (Q10) => 274.01 cfs
Detention Pond Stage - Storage Function
Contour Contour Incr. Accum. Stage
Elev. Area Storage Storage (S) (Z)
(ft) (sf) (cf) (cf) (ft) ln (S) ln (Z) Z est
210.0 - - - - -
210.0 30,998 2 2 0.00 0.44 -9.21 0.00
210.5 33,886 16,221 16,223 0.50 9.69 -0.69 0.47
211.5 36,901 35,394 51,616 1.50 10.85 0.41 1.35
212.5 40,044 38,473 90,089 2.50 11.41 0.92 2.24
213.5 43,316 41,680 131,769 3.50 11.79 1.25 3.16
214.5 46,716 45,016 176,785 4.50 12.08 1.50 4.13
215.5 50,233 48,475 225,259 5.50 12.33 1.70 5.15
216.5 53,827 52,030 277,289 6.50 12.53 1.87 6.21
217.5 57,484 55,656 332,945 7.50 12.72 2.01 7.33
218.5 61,203 59,344 392,288 8.50 12.88 2.14 8.51
219.5 64,982 63,093 455,381 9.50 13.03 2.25 9.74
220.5 68,820 66,901 522,282 10.50 13.17 2.35 11.03
221.5 72,715 70,768 593,049 11.50 13.29 2.44 12.37
222.5 76,667 74,691 667,740 12.50 13.41 2.53 13.78
223.5 80,675 78,671 746,411 13.50 13.52 2.60 15.24
224.5 84,739 82,707 829,118 14.50 13.63 2.67 16.76
Regression Output:
b= 1.10 (X Variable Coeff)
Ks=36,959 (ey-intercept)
Stage - Storage Equation is of the form: S = (Ks)(Z)b
printed: 3/19/2019 6:26 PM Page 1 of 20
4D Site Solutions, Inc.
Primary Spillway
Barrel
Number of Barrels = 1
Dia. of Barrel = 18 inches
Area of Barrel, (Ab) = 1.77 sf
Pipe Length, (L) = 100.0 feet
Friction Coeff., (Kp) = 0.01550
Inv. of Barrel = 210.00 feet
Riser
Elev. of Riser Crest = 216.80 feet
Rectangular
Length Weir= 72 inches Width Weir= 72 inches
Total Weir Length= 24.00 feet
Area of Riser = 36.00 sq. ft.
Orifice in Riser
Dia. of Orifice = 5.00 inches
Number of Orifices = 1
Area of Orifice, (Ab) = 0.14 sf
Orifice Coefficient (Cd) = 0.60
Inv. of Orifice = 210.00 feet
Length of weir= 2.50 feet
Top of weir= 212.75 feet
Weir Coefficient (Cw)= 3.00
Emergency Spillway
Width of Spillway (Approx.) = 30 feet
Weir Coefficient = 3.3
Crest Elevation = 223.00 feet
Summary of Results
Maximum Release Rate, (Q10) = 139.32 cfs
Release Rate, (Q10) = 134.91 cfs
Normal Water Surface Elev. = 210.00 feet

Water Surface Elev. @ Outlet (Q10) =217.58 feet
printed: 3/19/2019 6:26 PM Page 2 of 20