TABLE 2: RURAL RUNOFF COEFFICIENTS (1)

Type of Surface	Runoff Coefficient "C"
Woodland (Sandy)
Flat (0-5% Slope)	0.10
Rolling (5-10% Slope)	0.25
Steep (greater than 10%)	0.30
Woodland (Clay)
Flat (0-5% Slope)	0.30
Rolling (5-10% Slope)	0.35
Steep (greater than 10%)	0.50
Pasture (Sandy)
Flat (0-5% Slope)	0.10
Rolling (5-10% Slope)	0.16
Steep (greater than 10%)	0.22
Pasture (Clay)
Flat (0-5% Slope)	0.30
Rolling (5-10% Slope)	0.36
Steep (greater than 10%)	0.42
Cultivated (Sandy)
Flat (0-5% Slope)	0.30
Rolling (5-10% Slope)	0.40
Steep (greater than 10%)	0.52
Cultivated (Clay)
Flat (0-5% Slope)	0.50
Rolling (5-10% Slope)	0.60
Steep (greater than 10%)	0.72

 

   (1)   From HERPICC Stormwater Drainage Manual - Revised July 1994.