This 2-hour interactive online course presents the basics of the SCS Method of determining runoff, using Technical Release No. 55 (TR 55), “Urban Hydrology for Small Watersheds.” While the Soil Conservation Service (SCS) has changed their name to the Natural Resources Conservation Service (NRCS), this method is still commonly called the SCS Method, rather than the NRCS Method. The SCS Method is a very commonly used method to determine runoff from smaller drainage basins. The document was released in 1986 and, while it has not been updated to include the common use of personal computers, many of the techniques included are easily adaptable to spreadsheet programs.
This course is the second of a two-part course that provides all of the SCS Methods included in TR 55. Part 1 covers the first four chapters of TR 55, which include the Introduction, Estimating Runoff, Time of Concentration and Travel Time and the Graphical Peak Discharge Method. Part 2 covers chapters 5 and 6, which include the Tabular Hydrograph Method and Storage Volume for Detention Basins. The SCS Method is a relatively straightforward method that can be applied in many cases. Unlike many hydrologic techniques, it is a method that produces results that can be duplicated by others without great difficulty. A number of computer programs are available that use the SCS Method. However, use of these programs without an understanding of the assumptions and limitations of the method can result in substantial errors. The text of the course is taken from TR 55.
Water / Stormwater Management
Health, Safety and Welfare
At the conclusion of the course, you will be able to:
•Compute the peak discharge using the Tabular Hydrograph Method
•Determine a hydrograph, using the Tabular Hydrograph Method
•Estimate the required storage for a detention basin, using the SCS Method