This 3-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 first of a two-part course series that provides all of the SCS Method 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 chapter 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. The text of the course is taken from TR 55.
Water / Stormwater Management
Health, Safety and Welfare
At the conclusion of this course, the student will be able to:
•Determine an appropriate Curve Number value for many different land uses and soil types
•Estimate the amount of runoff, using the SCS Method
•Compute time of concentration and travel time using the methods presented in TR 55
•Compute the peak discharge using the Graphical Peak Discharge Method
Mark Peterson, Kadrmas, Lee and Jackson