Problem 1:
A triangular shaped swale is to retain the runoff from a catchment with a design runoff rate of .01 m3/sec. The longitudinal slope of the swale is to be 1.5% with side slopes of 5:1 (H:V). If the grassed swale has a Manning’s n of 0.030 and a minimum infiltration rate of 200 mm/hr,determine the length of the swale required.
Problem 2:
A large circular parking lot with a diameter of 400 feet is being constructed as overflow parking for the state fair grounds. All stormwater will drain as sheet flow to the center, flow into a drop inlet, and travel through a pipe system to the nearest stream. The parking lot will be mowed grass (clay soil) with a slope of 2 percent toward the center. The 2-yr, 24-hr rainfall is 2.4 inches. Using SCS procedures to determine the time of concentration and IDF curve in the power point slides, determine the 10-year peak discharge that will be required to design the pipe system.