Surface waters in reservoirs constitute a significant water source for the rapidly growing population in the cross timbers ecoregion

This $627,404 Cooperative Agreement award from the U.S. Department of the Interior's Bureau of Land Management Idaho Region under the Joint Fire Science Program (CFDA 15.232) aims to assess the impact of prescribed fire regimes on water quantity and quality in the Cross Timbers region of Oklahoma. The primary objectives are to evaluate the effects of prescribed fire on vegetation, soil, water yield, and water quality, as well as model the application of prescribed fire on water resources under current and future climate scenarios. The project will utilize existing experimental watersheds in Oklahoma and the results will provide scientific evidence to support efforts to promote prescribed fire for controlling invasive woody species and enhancing municipal water supplies in the region. The award has a performance period from September 2024 to August 2028 and the prime recipient is Oklahoma State University, a public land-grant research university.

These reservoirs are often surrounded by grasslands and OAK woodlands where woody species are encroaching rapidly leading to reported declines in water quantity and quality. Prescribed fire is commonly considered a tool for mitigating woody expansion and reducing wildfire risks but its effectiveness in enhancing water yield and quality in cross timbers reservoirs is not well understood. Our primary objective is to assess the effect of prescribed fire regimes on water quantity and quality in the cross timbers region under current and future climates. Our central hypothesis is that properly applied prescribed fire may effectively enhance water yield and improve water quality in reservoirs within the cross timbers region. We will evaluate the impact of prescribed fire on vegetation and soil and quantify its effects on water quantity and quality. We will also model the application of prescribed fire on water quantity and quality in three municipal water supply reservoirs under both current and future climate scenarios. This project will utilize our existing experimental watersheds in oklahoma. The results will provide scientific evidence supporting efforts to promote prescribed fire for controlling invasive and encroaching woody species in the southcentral great plains. Municipal water suppliers in the cross timbers region will be able to assess the impact of prescribed fire on water supply through our watershed level simulations. Anticipated outcomes include understanding the utilization and effectiveness of prescribed fire to sustainably manage woody encroachment and enhance water quantity and quality for municipal water supply reservoirs. Project results will be disseminated to a wide range of stakeholders through field tours workshops and scientific publications.