At least three reservoirs likely will be contaminated by erosion in areas burned by this season's record wildfires, according to a University of Colorado at Boulder researcher. The South Platte watershed and Cheesman Reservoir, one of Denver's important water sources, will be affected by erosion from the Hayman fire, while the Missionary Ridge fire could affect the Vallecito and Lemon reservoirs, according to John Gartner, a research assistant at CU-Boulder's Institute for Arctic and Alpine Research.