Potential impacts of phosphorous loading from wildfire-fighting retardants related to the East Troublesome fire on surface water quality in Willow Creek and Willow Creek Reservoir

Project ID: 22019
Principal Investigator: Lindsay Bearup
Research Topic: Water Quality
Funded Fiscal Years: 2022, 2023 and 2024
Keywords: None

Research Question

This project is designed to address the overarching question of:

What is the impact of the application of wildfire-fighting retardant on phosphorous concentrations and mass flux in surface waters?

It is hypothesized that phosphorus loading from the use of fire-fighting chemicals could have a multi-year response and longer impacts to water quality depending on how it is stored and moves in the watershed. To specifically address this hypothesis and inform a conceptual model of phosphorous fate and transport, this research will answer the following questions in the Willow Creek drainage in the East Troublesome burn area:
-Does the application of wildfire-fighting retardant lead to increased phosphorous transport in surface waters draining burned and burned-adjacent areas?
-Does phosphorous transport occur dominantly as dissolved solutes or with solids as part of the suspended or bedload?
-What is the predicted mass flux of phosphorous, both as dissolved and with solids, into Willow Creek Reservoir?
-What is the fate of phosphorous in Willow Creek reservoir? Does stratification of the reservoir need to be considered when predicting phosphorous behavior in Willow Creek Reservoir? To what extent is phosphorous behavior influenced by iron chemistry, as insoluble iron-phosphate compounds may form.
-Are there temporal changes in phosphorous behavior? If so, at what time scales?

Need and Benefit

This proposal addresses the need by identifying changes in reservoir water quality from wildfire and anthropogenic attempts to control fires using fire-fighting chemicals, focusing on phosphorus, which impacts other water quality variables, notably algae. The proposal was discussed with EN Coordinator Jennifer Bountry, and Water Quality Coordinator Mike Horn. The proposal was also highlighted at the Research Office's Wildfire Research Needs Workshop.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Please contact research@usbr.gov about research products related to this project.


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Last Updated: 6/22/20