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Environmental Flows in Texas: Successes and Lessons Learned

Texas accelerated work on environmental flows in earnest after passage of state legislation in 2007. The Texas Commission on Environmental Quality was delegated responsibility for creating environmental flow standards to guide development of future water use permits. The TCEQ defines environmental flows as, “…an amount of water that should remain in a stream or river for the benefit of the environment of the river, bay, and estuary, while balancing human needs.”

By 2009, a comprehensive, phased process was in place to guide creation of environmental flow standards. With similarities to the regional water planning process, stakeholder committees were created for major river basins. Each stakeholder committee elected a team of scientists charged with using consensus and the best available information, without consideration of impacts to human needs, to:

  • Recommend water bodies for which environmental flow standards should be created,
  • Determine whether those water bodies are “sound ecological environments,” and
  • Recommend flow regimes to maintain or restore sound environments.

Science teams were given a year to produce recommendations.

Environmental flow regimes are seasonal and yearly flows for specific areas that will support the productivity, physical extent and key habitats of those areas. By 2014, environmental flow standards had been created for streams and estuaries in 11 major river basins.

A variety of lessons were learned in this process:

  • Uncertainty was highest when the process started. The first basins started work when guidance was still in development. The comfort level of scientists, stakeholders and regulators grew as the process continued.
  • Consensus was critical to moving forward. Legislatively mandated deadlines forced groups to work rapidly towards decisions.
  • Ecological data relating flow regimes to environmental health at specific locations was practically nonexistent and understanding of relationships between flow variability and ecosystem health is still limited. These limitations led to a subset of historical flows forming the basis for flow standards at many locations.

In anticipation of these challenges, adaptive management was incorporated in the legislation, allowing a ten-year period following creation of flow standards to conduct studies and evaluate whether the flow standards should be modified. The state has funded $4 million for those adaptive management studies to date.

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