Determine the size of outfall sewer below MH1 needed to serve the 12-acre drainage area in...

Determine the size of outfall sewer below MH1 needed to serve the 12-acre drainage area in below Figure. Each area has an inlet time of 10 min. The coefficient of runoff for the two housing areas is 0.45, and the park is 0.15. The distance between manholes is 600 ft, and all pipes are set on a slope of 0.0020. The rainfall intensity- duration relationship is i = 131 divided by t + 19, where i = inches per hour and t = minutes.