SW6210501_1736-DITCH CALCS_20210518

1736 - Rolling Springs Section 7
Ditch Calculations
Ditch #1
Sandalwood Dr Sta. 2+50 to 4+00 right
Tc= 20.9 min, use 15 min
Kirpich: L = 590 If; n = 0.4; s = 0.056
DA=1.54ac
C = 0.35
1 = 5.25 i n/h r
Q = 2.83 cfs
Ditch #2
Sandalwood Dr Sta. 4+00 to 7+50 right
Tc = 19 min + 3.9 min = 22.9 min, use 22.5 min
Kirpich: L = 533 If; n = 0.4; s = 0.06
Kerby: L = 230 If; s = 0.005
DA = 3.27 ac
C = 0.35
1 =4.52 in/hr
Q = 5.17 cfs
Ditch #3
Sandalwood Dr Sta. 7+50 to 9+50 right
Tc = 19 min + 5.8 min = 24.8 min, use 22.5 min
Kirpich: L = 533 If; n = 0.4; s = 0.06
Kerby: L = 540 If; s = 0.01
DA = 5.45 ac
C = 0.35
1 =4.52 in/hr
Q = 8.62 cfs
Ditch #4
Sandalwood Dr Sta. 9+50 to END right
Tc = 19 min + 9.0 min = 28 min, use 30 min
Kirpich: L = 533 If; n = 0.4; s = 0.06
Kerby: L = 673 If; s = 0.005
DA = 8.68 ac
C = 0.35
1 = 3.80 in/hr
Q = 11.54 cfs
Ditch #5
Sandalwood Dr Sta. 2+50 to 4+00 left
Tc=5 min
DA = 0.08
C = 0.8
1 = 7.79 in/hr
Q = 0.50 cfs
Ditch #6
Holly Ct Sta. 0+00 to 1+50 right
Tc=5 min
DA = 0.14 ac
C = 0.8
1 = 7.79 in/hr
Q = 0.87 cfs
Ditch #7
Holly Ct 1+50 to END right
Tc=5 min
DA=0.34ac
C = 0.8
1 = 7.79 in/hr
Q = 2.12 cfs

Ditch #8
DA = 0.80 ac
Holly Ct 0+00 to 1+50 left
C = 0.4
1 = 7.79 in/hr
Tc=5 min
DA = 0.21 ac
Q = 2.49 cfs
C = 0.8
1 = 7.79 in/hr
Ditch #13
Road A 0+00 to 1+00 right
Q = 1.31 cfs
Tc = 32 min + 4.5 min = 36.5 min, use 30 min
Ditch #9
Kirpich: L = 731 If; n = 0.4; s = 0.013
Holly Ct 1+50 to END left
Kerby: L = 1,030 If; s = 0.068
DA = 6.09 ac
Tc=5 min
C=0.4
DA = 0.46 ac
I = 3.80 i n/h r
C = 0.8
1 = 7.79 i n/h r
Q = 9.25 cfs
Q = 2.87 cfs
Ditch #14
Road A 0+00 to 1+00 left
Ditch #10
Tc = 19.2 min, use 15 min
Tc = 5 min
Kirpich: L = 566 If; n = 0.4; s = 0.073
DA = 0.80 ac
DA = 1.30 ac
C=0.8
C=0.45
1 = 7.79 in/hr
I = 5.25 in/hr
Q = 4.99 cfs
Q = 3.07 cfs
Ditch #11
Ditch #15
Road B 7+00 to END right
Tc=30 min
Tc=5min
DA=7.39ac
DA=0.44ac
C=0.45
C=0.4
1=3.08in/hr
1 = 7.79 in/hr
Q = 10.24 cfs
Q = 1.37 cfs
Ditch #12
Tc=5 min