Upper Poudre

How do wildfires affect water quality and algal growth in high elevation reservoirs, and are those changes propagated downstream?

The 2020 Cameron Peak wildfire (CPF) was the largest wildfire in Colorado history at over 200,000 acres. The CPF burned a large proportion of the Cache La Poudre watershed, in particular various high elevation reservoirs. These reservoirs provide valuable drinking and agriculutural water to users in the City of Fort Collins, Greeley, Thornton and Northern Water. In collaboration with the Rocky Mountain Research Station (USFS), we are sampling various reservoir, tributary, and mainstem sites of the Cache La Poudre watershed. This field campaign allows us to analyze trends in water quality focusing on nutrients and other key constituents mobilized post-fire. The goal of this project is to understand how these nutrients affect algal growth in reservoirs and how those changes are felt downstream. Using this field data, we are working to create a system that will predict algal blooms before they occur using a combination of in-stream sensors, remote sensing, and field sampling.