Trinity & San Jacinto Rivers/Galveston Bay Area
The Trinity River and San Jacinto River/Galveston Bay area contains two of the largest cities in the United States. The Trinity River begins north of the Dallas/Fort Worth metroplex and makes it way to Houston before it travels on to nourish Galveston Bay. The shorter San Jacinto River arises north of Houston and also flows into Galveston Bay.
The shallow waters covering Galveston Bay’s 600 square miles have historically produced as much as 80% of the oysters harvested in the state. The area’s blue crab and shrimp harvests are also some of the largest in Texas. Galveston Bay is loved by recreational anglers and its shallow waters are home to Atlantic croaker, flounder, spotted seatrout, and many other species of fish. Nearly three hundred different kinds of birds have been seen in the area around Galveston Bay. This natural diversity is due in large part to the freshwater that has historically flowed into Galveston Bay from the Trinity and San Jacinto rivers and local streams.
Key Points Related to the Senate Bill 3 Environmental Flows Allocation Process in this Area
- Both the expert science team and the stakeholder committee developed with split recommendations.
- The limited instream flow protections included in the environmental flow standards adopted by the Texas Commission on Environmental Quality (TCEQ) are set at levels lower than has been seen in the Trinity River in decades.
- The freshwater inflow protections adopted by TCEQ are based on the amount of water left over after water rights are accounted rather than on the amount needed to protect a sound ecological environment.
- The stakeholder committee recommended a five-year period for review and possible revision of the adopted flow standards.
Where do things stand with the Environmental Flows Allocation Process for this region?
Scientific flow recommendations submitted
The expert science team is charged with developing, through a collaborative process designed to achieve consensus, a recommended environmental flow regime, or set of flow recommendations, adequate to support a sound ecological environment and maintain key aquatic habitats. In developing recommendations, the science teams are directed to incorporate only scientific considerations and to use the best available science and guidance developed by the Science Advisory Committee. Unfortunately, the Trinity/San Jacinto Expert Science Team did not develop consensus recommendations, but, instead, developed two sets of competing recommendations.
The majority of the Expert Science Team recommended a comprehensive environmental flow regime that varies by season and includes a subsistence, or minimum, flow level, three levels of base flows, and a set of several different levels of pulse flows for each of 6 sites in the Trinity River basin, 4 sites in the San Jacinto River basin, and a site each in Buffalo and Brays Bayous. The majority also recommended seasonal criteria for freshwater inflows to Galveston Bay, although those recommendations were somewhat incomplete.
The minority faction of the Expert Science Team recommended a subsistence flow and a single base flow that vary by season for 2 sites on the Trinity River and 2 sites on the San Jacinto River. The minority faction also developed “conditional” recommendations for further study, but not for implementation, that included a second, higher, level of base flows and a single level of pulse flows at those same sites and at two additional sites on the Trinity River. The members of the minority faction also indicated support for a set of four levels of annual target inflows for Galveston Bay.
Stakeholder flow recommendations submitted
The Stakeholder Committee then had the challenge, within a six-month period, of taking those competing scientific recommendations and considering them along with other factors, such as human water supply needs, to develop their own recommendations for flow standards. Ultimately, faced with the challenge of having competing science-based recommendations as a starting point, the stakeholders did not reach consensus and also ended up submitting two sets of competing recommendations. The majority of the committee, made up primarily of representatives of water supply interests, submitted a very limited set of recommendations that matched those submitted by the minority faction of the Expert Science Team. The minority faction of the stakeholder committee developed a more comprehensive set of recommendations fairly closely modeled on the recommendations from the majority of the Expert Science Team. Both sets of recommendations were submitted to the Texas Commission on Environmental Quality and the Environmental Flows Advisory Group in May 2010.
Environmental flow standards adopted by The Texas Commission on Environmental Quality (TCEQ)
TCEQ is directed by statute to adopt flow standards that are adequate to support a sound ecological environment to the maximum extent reasonable when considering various factors. The overall structure and magnitude of the TCEQ flow standards, adopted in April 2011 by a 2-1 vote, closely match the recommendations of the majority of the stakeholder committee (and the minority faction of the Expert Science Team) but with a small increase in base flow amount. As a result, the flow standards provide little protection for river flows and for freshwater inflows to Galveston Bay. For stream and river reaches, the standards protect a lower level of flows than the default methodology TCEQ has used for years in the absence of site-specific criteria.
For Galveston Bay, the standards reflect an approximation of the amount of water likely to be available after all existing rights, plus some new ones, are fully exercised rather than an amount likely to support a sound ecological environment. The amounts and frequencies of the protected inflows are far below the historical levels of inflow actually experienced and far below levels that can reasonably be expected to protect a sound ecological environment.
Stakeholder committee submitted Work Plan for Adaptive Management
Senate Bill 3 recognizes that additional information will be needed to better inform adequate flow standards and that standards adopted now may need to be revised as better information becomes available. Accordingly, the stakeholder committees are charged with developing a work plan for adaptive management that identifies needed studies and monitoring and recommends a schedule for reviewing scientific information as well as for reviewing the flow standards and strategies to achieve compliance with the standards. The work plan, which was approved by all stakeholders, was submitted in June of 2012. In addition to recommending a number of studies, the work plan recommends a five-year review and revision cycle for the environmental flow standards. The Environmental Flows Advisory Group has not yet approved the work plan. The work plan does not address strategies to help meet the flow standards.
- The Texas Living Waters Project and other conservation partners submitted these comments to the Texas Commission on Environmental Quality on the draft standards-setting rule.
- The environmental flow standards adopted by the Texas Commission on Environmental Quality for this bay/basin region can be found here.
- Consult the Texas Commission on Environmental Quality webpage for information on the flows process in this region .
- Sign up to receive email updates from the Texas Commission on Environmental Quality on the environmental flows process for this region.
- Printable map of the region (PDF, 3 MB)
Please contact Jennifer Ellis for more information about the process in this region.