2011 SAC discussion paper consideration of attainment frequencies and hydrologic conditions in developing and implementing instream environmental flow regimes

At this point, the SAC considers it inappropriate and possibly misleading to suggest a single recommended approach for dealing with attainment frequencies in the development of e-flow regimes and implementation of those regimes through adopted environmental flow standards. Site-specific circumstances can dictate different methodologies, and the BBESTs, through their studies and eliberations, can decide on the best course of action for their respective basins in order to meet their legislative charge of developing e-flow regime recommendations "considerin all reasonably available science, wothout regard to the need for the water for other uses" (SB3, Sec. 11.02362m). On the other hand, the basin-bay stakeholders and the TCEQ, with their broader legislantive mandates under SB 3 to develop e-flow standards while also considering human needs for water, have greater latitude with regard to the structure and implementation of e-flow regimes, including the procedures used for addressing attainment frequencies.