Predicting the volume and rate of runoff from rain events is an essential skill for stormwater engineers. This class examines in detail all of the factors that influence runoff: precipitation, soils, ground cover, drainage area and time of concentration. Using TR-55 technology, and the latest soil and precipitation data, participants compute runoff for various pre- and post-development conditions by hand, and then by using a computer model. Determining detention storage volumes and modeling of reservoirs and outlet structures are also addressed.