Runoff Coefficient

Runoff Coefficient Table
Area Description Runoff Coefficient C
Business
Downtown 0.70-0.95
Neighborhood 0.50-0.70
Residential
Single-Family 0.30-0.50
Multiunits, detached 0.40-0.60
Multiunits, attached 0.60-0.75
Residential (suburban) 0.25-0.40
Apartment 0.50-0.70
Industrial
Light 0.50-0.80
Heavy 0.60-0.90
Parks, cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard 0.20-0.35
Unimproved 0.10-0.30
Pavement
Asphaltic and concrete 0.70-0.95
Brick 0.70-0.85
Roofs 0.75-0.95
Lawns, sandy soil
Flat, 2 percent 0.05-0.10
Average, 2-7 percent 0.10-0.15
Steep, 7 percent 0.15-0.20
Lawns, heavy soil
Flat, 2 percent 0.13-0.17
Average, 2-7 percent 0.18-0.22
Steep, 7 percent 0.25-0.35
http://www.ems-i.com/wmshelp/Hydrologic_Models/Models/Rational/Equation/Runoff_Coefficient_Table.htm