Last updated on 2022-09-28
Document was last updated on October 21, 2019.
Note: Model My Watershed web applications are under active development and the appearance of screenshots will change over time. Updates to this guide will be released with major changes to the ModelMW User Interface.
The Model My Watershed (ModelMW) Site Storm Model simulates storm runoff and water quality by applying the TR-55 and STEP-L water quality models for a single 24-hour rainstorm over a selected land area within the continental United States. The results are calculated based on actual land cover data (from the USGS National Land Cover Database 2011, NLCD2011), and actual soil data (from the USDA Gridded Soil Survey Geographic Database, gSSURGO) for the selected land area of interest.
The complementary ModelMW Runoff Simulation performs the same model calculations on a hypothetical land parcel with a single land cover class and a single hydrologic soil group.
There are additional resources that explain in-depth technical details about the models.