Slide 6 of 75
Notes:
The volumetric runoff coefficient can be defined as a measure of the amount of rainfall that is converted to runoff. The runoff coefficient ranges from 0 to about .95. In natural situations with no impervious cover, the runoff coefficient is typically in the .05 - .10 range. By the time the watershed is fully paved, 15 to 20 times more runoff can occur as compared to measurements prior to development.
This graph shows that as the percentage of watershed imperviousness increases, the volumetric runoff coefficient increases as well.