A 152 m  152 m (500 ft X 500 ft) parcel of agricultural land is to be developed into high-...

A 152 m  152 m (500 ft X 500 ft) parcel of agricultural land is to be developed into high-density residential housing. Soils on the property are in hydrologic soil group B, with an average slope of 2 percent. Compute the runoff from the parcel before and after development for a 100-year return period storm. The estimated time of con­centration was 40 minutes before development and 20 minutes after development. Coefficients for the rainfall intensity equation (10.2) are a = 2,692 for I in mm/hr (106 / in in./hr), b = 9.0, and c = 0.792.