--- title: "SCS Rainfall Method" canonical: "https://help.innovyze.com/space/infodrainage2021v1/16548147/SCS%20Rainfall%20Method" format: markdown --- **The SCS Rainfall Method** was developed by the [United States Department of Agriculture - ](http://www.nrcs.usda.gov/)[Natural Resources Conservation Service](http://www.nrcs.usda.gov/) (USDA-NRCS). It generated four synthetic 24-hour rainfall distribution curves that cover all geographical regions of the United States. These curves are described in Appendix B of Technical Release 55. > ⚠️ This method may not be available for your region. For more information, refer to the [Regionalisation](https://help-innovyze.atlassian.net/wiki/spaces/infodrainage2021v1/pages/16548015) topic. Use the controls described below to generate SCS rainfall to be run by the analysis. **Generate SCS Data** This link directs users to the National Weather Service website: [http://hdsc.nws.noaa.gov/hdsc/pfds/](http://hdsc.nws.noaa.gov/hdsc/pfds/).  Users can look up the appropriate rainfall details for their area if they are not already know or locally specified.  **ARI Events Spreadsheet:** ***ARI (Years)*** A range of typical Annual Recurrence Intervals (ARI) listed for the SCS method. *Note: The WQe option is a 3 month Water Quality Event.* ***Use*** Check the ARIs to be solved during the Analysis ***Depth*** Cumulative depth multiplier to the SCS hyetograph distribution - discussed below. ***Run Time*** Simulation run time, by default this is twice the hyetograph duration (24hours for standard SCS hyetograph). **Distribution** SCS hyetograph distributions Type 1, 1A, 2 and 3 are available by default.  If an SCS hyetograph other than these is desired it is recommended to use the Design Storm (User Defined) option.