Hydrologic Modeling

Watershed conditions change after wildfires. Calculating the runoff response to these changed conditions is critical to the protection of life and property after the fire.

Upper Squaw Creek erosion

Rain over a burned area can create:

  • More and faster runoff than normal, especially from high-intensity storms.
  • Large amounts of sediment, which may reduce storage capacity in a reservoir or clog drainages and culverts.
  • Debris flows or downed timber, which may obstruct roadways and damage infrastructure.
Many tools and models are available for assessing post-wildfire runoff. Read below for more information.

The PWFC does not offer endorsements in either direction of the tools and models below. This page is intended to be an inventory of common resources, not a validation of any particular application.

Guides and Tools

The Washington Department of Ecology Dam Safety Office has developed some resources to be used as a starting point for qualified consultants to assess hydrology changes after a wildfire:

  1. Guidance for assessing post-wildfire hydrology
  2. Spreadsheet for calculating post-wildfire watershed parameters

The Natural Resource Conversation Service has also compiled some comprehensive guidance for performing post-wildfire hydrologic analyses. It includes case studies and examples.

  1. USDA NRCS Hydrologic Analyses of Post-Wildfire Conditions August 2016

Downloadable Models