SW6200905_1669-DITCH CALCS_20201008

1669 - Currin Hill Subdivision
Ditch Calculations Q = 2.57 cfs
Ditch #1
Ditch #5
Road A Sta. 0+00 to 2+75 left
Road A Sta. 22+50 to 27+00 left
Tc=15min
Tc=30min
DA=1.65ac
DA=1.67ac
C = 0.5
C = 0.5
1 = 5.26 in/hr
I = 3.81 in/hr
Q = 4.33 cfs
Q = 3.18 cfs
Ditch #2
Ditch #6
Road A Sta. 2+75 to 3+50 left
Road A Sta. 7+50 to 11+00 right
Tc= 15 min
Tc=5 min
DA = 2.62 ac
DA = 0.30 ac
C=0.5
C=0.95
1= 5.26 i n/h r
1= 7.80 i n/h r
Q = 6.89 cfs Q = 2.22 cfs
Road A Sta. 7+00 to 11+00 left Road A Sta. 11+00 to 15+50 right
Tc= 10 min
Tc=30 min
DA=0.77ac
DA=1.44ac
C = 0.5
C = 0.5
1 = 6.24 in/hr
I = 3.81 in/hr
Q = 2.40 cfs
Q = 2.74 cfs
Ditch #4
Ditch #8
Road A Sta. 11+00 to 22+50 left
Road A Sta. 15+50 to 21+00 right
Tc = 19.9 min + 5.4 min = 25.4 min, use 30 min
Tc=30min
Kerby: 355 If, s = 0.025, n = 0.4
DA = 3.02 ac
Kirpich: 683 If, s = 0.02
C = 0.5
DA = 1.35 ac
I = 3.81 in/hr
C = 0.5
1 = 3.81 in/hr
Q = 5.75 cfs

Ditch #9
Road A Sta. 21+00 to 27+00 right
Tc=30 min
DA = 4.87 ac
C = 0.5
1 = 3.81 i n/h r
Q = 9.28 cfs