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Environmental Flows Rules

Summary of the statutory authority and information related to the TCEQ's environmental flow rulemaking process as required by House Bill 3 and Senate Bill 3 and the associated adopted environmental rules.


Statutory Authority

The commission by rule shall:

  1. adopt appropriate environmental flow standards for each river basin and bay system in this state that are adequate to support a sound ecological environment, to the maximum extent reasonable considering other public interests and other relevant factors;
  2. establish an amount of unappropriated water, if available, to be set aside to satisfy the environmental flow standards to the maximum extent reasonable when considering human water needs; and
  3. establish procedures for implementing an adjustment of the conditions included in a permit or an amended water right as provided by Sections 11.147(e-1) and (e-2).

For more information on Environmental Flow Rules and Rulemaking, please contact the Water Availability Division at (512) 239-4600, or e-mail

Adopted Environmental Flow Rules* (in PDF)

* The rules the TCEQ makes available on this site as a public service are not a substitute for the official rules as approved and filed with the Office of the Secretary of State. See full disclaimer. The TCEQ assumes no legal liability or responsibility for the accuracy or completeness of any information provided on this site. Official copies of TCEQ rules may be obtained by emailing