Santa Clara Watershed Assessment Study


In July 2011, the unprecedented Las Conchas Fire burned 156,548 acres on many watersheds including Santa Clara Creek watershed. During and after precipitation events, these watersheds have been affected by increased runoff with debris and accelerated rates of erosion, which typically occur after a fire. Surface infiltration is greatly decreased by the heat of the fire physically altering the surface permeability and destroying forest floor vegetation. This results in significant loss of rainfall storage in the soil, with a consequent reduction in runoff attenuation capability. Ash accumulation on the forest floor further reduces soil infiltration and enhances precipitation runoff. The magnitude of large storm flows increases dramatically after wildfires. For instance, after the La Mesa Fire in 1977, peak flows at the most downstream streamflow-gaging station in Frijoles and Capulin Canyons (downstream from Santa Clara Pueblo and above Cochiti Reservoir) increased to about 160 times the maximum recorded flood prior to the fire.