Statewide Environmental Flows (SB3)

The 80th Texas Legislature (2007) established the Senate Bill 3 (SB3) process for environmental flows in order to determine environmental flow standards for all of the major river basins and bay systems in Texas. Senate Bill 3 was designed to be an accelerated, stakeholder-driven, scientific and consensus-based process to establish environmental flow recommendations from which the Texas Commission on Environmental Quality (TCEQ) could set standards. An important second output from the Senate Bill 3 process are work plans that describe additional data and detailed studies which are needed as part of the adaptive management component of the legislation to refine Senate Bill 3 recommendations and standards.

The intent of the Senate Bill 3 process is to address three major questions:

  1. How much water is needed to sustain a sound ecological environment in the state's rivers and estuaries?
  2. How can this water be protected?
  3. What is the appropriate balance between water needed to sustain a sound ecological environment and water needed for human or other uses?

Senate Bill 3 science teams are tasked with using the best available science to address the first question and are to consider only the environmental needs of their respective basins and bays. The second and third questions are to be considered by Senate Bill 3 stakeholder committees and by the TCEQ. The process also involves a statewide Environmental Flows Advisory Group and a statewide Science Advisory Committee to oversee the basin-specific efforts.

As of 2015, seven of 11 river basins have completed the process of developing instream flow and freshwater inflow recommendations. Because Senate Bill 3 was designed to be an accelerated process, the science teams for each basin had only one year to develop flow recommendations, and their corresponding stakeholder committees had only six months to develop their recommended flow standards. Following completion of the science team and stakeholder recommendations, the TCEQ then had one year in which to develop and adopt instream flow and freshwater inflow standards for a basin. The TCEQ now has adopted instream flow and/or freshwater inflow standards for seven basins:

The 83rd Texas Legislature (2013) authorized funding for the purpose of studying environmental flow needs for Texas rivers and estuaries as part of the adaptive management phase of the Senate Bill 3 process. From this funding, 15 studies were completed across five basin-bay areas. The final reports from this effort are listed by basin-bay system below:

Trinity-San Jacinto River Basin and Galveston Bay

Quigg, A., and J. Steichen.  2015.  Defining Bioindicators for Freshwater Inflow Needs Studies.  Final report to the Texas Water Development Board for contract #1400011695.  Texas A&M University at Galveston, Galveston, Texas.  139 p.

Mangham, W., T. Osting, and D. Flores.  2015.  LiDAR Acquisition and Flow Assessment for the Middle Trinity River.  Final report to the Texas Water Development Board for contract #1400011696.  Texas A&M University at Galveston, Galveston, Texas.  139 p.  Trinity River Authority, Arlington, Texas.  138 p.

USGS.  2015.  Project Summary: Determination of Freshwater Inflow Volume from the Trinity River into Galveston Bay, May 2014 - August 2015.  Final report to the Texas Water Development Board for contract #1400011697.  United States Geological Survey, Conroe, Texas.  27 p.

Brazos River Basin and its associated estuary system

Bonner, T., J. Duke, G. Guillen, K. Winemiller, and BIO-WEST.  2015.  Instream Flows Research and Validation Methodology Framework and Brazos Estuary Characterization.  Final report to the Texas Water Development Board for contract #1400011722.  BIO-WEST, Inc., Round Rock, Texas.  202 p.

Colorado-Lavaca River Basin and Matagorda and Lavaca bays

Anchor QEA, BIO-WEST, J.F. Trungale Engineering and Science, and Soniat, T.  2015.  Studies to Evaluate Achievement of Freshwater Inflow Standards and Ecological Response.  Final report to the Texas Water Development Board for contract #1400011715.  Anchor QEA, LLC, Austin, Texas.  273 p.

Austin, B., A. Kennedy, T. Osting, and C. Walker.  2015.  Evaluation of Freshwater Delivery Alternatives to East Matagorda Bay.  Final report to the Texas Water Development Board for contract #1400011759.  AquaStrategies, Austin, Texas.  57 p.

Guadalupe, San Antonio, Mission and Aransas river basins and Mission, Copano, Aransas and San Antonio bays

San Antonio River Authority, T. Bonner, J. Duke, and BIO-WEST.  2015.  Instream Flows Research and Validation Methodology Framework.  Final report to the Texas Water Development Board for contract #1400011709.  San Antonio River Authority, San Antonio, Texas.  187 p.

Carothers, R., B.R. Hodges, P. Passalacqua.  2015.  Guadalupe Bayou Flow and Inundation Study.  Final report to the Texas Water Development Board for contract #1400011710.  Center for Research in Water Resources, The University of Texas at Austin, Austin, Texas.  51 p.

Black, B.A. and M. Heaney.  2015.  Rangia Clam Investigations.  Final report to the Texas Water Development Board for contract #1400011711.  San Antonio River Authority, San Antonio, Texas.  44 p.

Buskey, E. J., L. P. Scheef, and J. Xue.  2015.  Assessing the Effects of Freshwater Inflows and Other Key Drivers on the Population Dynamics of Blue Crab and White Shrimp Using a Multivariate Time-Series Modeling Framework.  Final report to the Texas Water Development Board for contract #1400011712.  University of Texas Marine Science Institute, Port Aransas, Texas.  151 p.

San Antonio Bay Partnership, Trungale Engineering and Science, and ARS Systems.  2015.  Strategy Options for Meeting Attainment Frequencies for the Estuaries.  Final report to the Texas Water Development Board for contract #1400011713.  San Antonio Bay Partnership, Inc., Victoria, Texas.  73 p.

Nueces River Basin and Corpus Christi and Baffin bays

Shockley, C.  2015.  Nueces BBASC Work Plan Study No. 1: Re-examination of the 2001 Agreed Order Monthly Targets and Safe Yield Versus Current Demand Evaluations.  Final report to the Texas Water Development Board for contract #1400011716.  HDR, Inc., Austin, Texas.  156 p.

Lemonds, P.J.  2015.  Nueces BBASC Work Plan Study No. 3: Nueces Watershed Pre- and Post-Development Nutrient Budgets.  Final report to the Texas Water Development Board for contract #1400011718.  HDR, Inc., Austin, Texas.  808 p.

Li, Z., and B.R. Hodges.  2015.  Modeling Salinity Fluxes in the Nueces Delta.  Final report to the Texas Water Development Board for contract #1400011719.  Center for Research in Water Resources, The University of Texas at Austin, Austin, Texas.  49 p.

Dodson, J., K. Dunton, E. Hill, B. Hodges, G. Jackson, B. Nicolau, D. Sullivan, K. Thompson, G. Ward.  2015.  Using Landform and Hydraulic Modifications to Increase the Benefit of Fresh Water Inflows to Nueces Bay and Nueces Delta.  Final report to the Texas Water Development Board for contract #1400011717.  Naismith Engineering, Inc., Corpus Christi, Texas.  135 p.

Top