30 Tex. Admin. Code § 298.5
This chapter contains the environmental flow standards and set-asides required by Texas Water Code (TWC), §11.1471. The commission adopts these environmental flow standards for each river basin and bay system in this state as the commission receives recommendations from basin and bay area stakeholders in accordance with TWC, §11.02362. The commission finds that the environmental flow standards adopted herein are adequate to support a sound ecological environment, to the maximum extent reasonable, considering other public interests and other relevant factors as described in TWC, §11.1471(b). The environmental flow standards adopted herein are schedules of flow quantities, reflecting seasonal and yearly fluctuations that vary geographically by specific location in a river basin and bay system.
30 Tex. Admin. Code § 298.5