SW6201001_Calcs (Ditch)_20201008

1689 — Evelyn Estates Subdivision
Ditch Calculations
Ditch #1
Road A right
Tc = 26.2 min + 5.9 min = 32.1 min; use 30 min
Kerby: L = 527 If, s = 0.017, n = 0.4
Kirpich: L = 391 If, s = 0.005
DA=9.04ac
C=0.5
1 = 3.88 in/hr
Q = 17.54 cfs
Ditch #2
Road A left
Tc = 17.2 min + 14.2 min = 31.4 min; use 30 min
Kerby: L = 262 If, s = 0.025, n = 0.4
Kirpich: L = 1,207 If, s = 0.005
DA = 6.53 ac
C=0.5
1 = 3.88 in/hr
Q = 12.67 cfs
Ditch #3
End of Road A
Tc = 30 min
DA = 16.51 ac
C=0.5
1 = 3.88 in/hr
Q = 32.03 cfs