Hydrologic Modeling

Watershed conditions change after wildfires.

Heavy rains in a burned area can create:

  • More and faster runoff from rainfall, especially 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.
Tools are available for assessing post-wildfire runoff

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