The Texas Instream Flow Program: Developing Instream Flow Recommendations With Consideration for Mussels

The Texas Instream Flow Program (TIFP), created by the Texas Legislature in 2001, is administered by the Texas Commission on Environmental Quality, Texas Parks and Wildlife Department, and Texas Water Development Board.  The TIFP is charged with conducting comprehensive, instream-flow studies to assess how much water is needed to maintain a sound ecological environment in rivers.  Through a collaborative process with stakeholders, specific goals and objectives are incorporated into study designs and technical studies focused on biology, hydrology/hydraulics, geomorphology, water quality, and connectivity.  Through the stakeholder process, indicator species are identified and have included mussels, which are important given their sensitivity to water quality and habitat alterations and the requirement of a fish host to complete their life cycle.  The TIFP is currently conducting technical studies to determine mussel distribution and habitat suitability criteria for inclusion in spatially-explicit hydrodynamic models.  Assessing the relationship between hydraulic habitat and mussel beds will be important in developing instream flow recommendations.