Flow alteration – from new and existing water supply projects, increased urbanization, and drought conditions – is a pervasive threat to aquatic wildlife throughout the Gulf Coast Prairie region. One species susceptible to this threat is Guadalupe Bass, an economically and ecologically important black bass species endemic to Texas. The area encompassing their range is projected to experience some of the highest population growth in Texas, placing increased demands on the aquifers and watersheds of this region. A previous GCP LCC Instream Flow project conducted by the Southeast Aquatic Resources Partnership (SARP) produced hypotheses about instream flow requirements of native aquatic species that need to be tested. This project will clarify how changes in flow are likely to affect Guadalupe Bass and will make recommendations for conservation of this priority species. Knowledge of how to manage sustainable Guadalupe Bass populations will benefit invertebrates, such as Quadrula mussels, and other fish species with similar instream flow requirements.