(a) A water right application in the Guadalupe and San Antonio River Basins and the San Antonio-Nueces Coastal Basin, which increases the amount of water authorized to be stored, taken, or diverted as described in §298.10 of this title (relating to Applicability), shall not cause or contribute to an impairment of the inflow regimes as described in the figures in this subsection. Impairment of the inflow regime shall be evaluated as part of the water availability determination for a new water right or amendment that is subject to this subchapter. For purposes of this subsection, impairment would occur if the application, when considered in combination with any authorizations subject to this subchapter, which were issued prior to this application, would impair the modeled permitting frequency of any inflow regime by more than the values set out in paragraphs (3)(A) - (C) and (4)(A) - (C) of this subsection.
(1) Impairment to the modeled permitting frequency shall be calculated individually for each inflow regime level in Figure: 30 TAC §298.380(a)(3) and Figure: 30 TAC §298.380(a)(4) for which a specific frequency is identified at the most downstream point in the water availability model, which represents inflows to San Antonio Bay.
(2) Impairment is calculated by addition or subtraction of the values set out in paragraphs (3)(A) - (C) and (4)(A) - (C) of this subsection, except that impairment of inflow regime Spring 4 and Spring 5 combined shall be calculated as set out in paragraph (3)(C) of this subsection.
(3) Bay and Estuary Freshwater Inflow Standards for the San Antonio Bay System for the Spring Season.
(4) Bay and Estuary Freshwater Inflow Standards for the San Antonio Bay System for the Summer Season.
(5) Bay and Estuary Freshwater Inflow Standards for Mission and Aransas Bays for the Summer Season.
(b) To the extent that strategies are implemented through a water rights permit or amendment to help meet the freshwater inflow standards for San Antonio, Mission, Aransas, and Copano Bays, a water right application in the Guadalupe and San Antonio River Basins and the San Antonio-Nueces Coastal Basin, which increases the amount of water authorized to be stored, taken or diverted as described in §298.10 of this title, shall not reduce the modeled permitting frequency for any inflow regime level, listed in Figure: 30 TAC §298.380(a)(1), Figure: 30 TAC §298.380(a)(2), and Figure: 30 TAC §298.380(a)(3), below the level that would occur with the permitted strategy or strategies in place.
(c) The following environmental flow standards are established for the following described measurement points:
(1) Guadalupe River at Comfort, Texas, generally described as United States Geological Survey (USGS) gage 08167000, and more particularly described as Latitude 29 degrees, 57 minutes, 86 seconds; Longitude 98 degrees, 53 minutes, 49.80 seconds.
(2) Guadalupe River near Spring Branch, Texas, generally described as USGS gage 08167500, and more particularly described as Latitude 29 degrees, 51 minutes, 37 seconds; Longitude 98 degrees, 23 minutes, 00 seconds.
(3) Blanco River at Wimberley, Texas, generally described as USGS gage 08171000, and more particularly described as Latitude 29 degrees, 59 minutes, 39 seconds; Longitude 98 degrees, 05 minutes, 19 seconds.
(4) San Marcos River at Luling, Texas, generally described as USGS gage 08172000, and more particularly described as Latitude 29 degrees, 39 minutes, 58 seconds; Longitude 97 degrees, 39 minutes, 02 seconds.
(5) Plum Creek near Luling, Texas generally described as USGS gage 08173000, and more particularly described as Latitude 29 degrees, 41 minutes, 58 seconds; Longitude 97 degrees, 36 minutes, 12 seconds.
(6) Guadalupe River at Gonzales, Texas, generally described as USGS gage 08173900, and more particularly described as Latitude 29 degrees, 29 minutes, 03 seconds; Longitude 97 degrees, 27 minutes, 00 seconds.
(7) Sandies Creek near Westhoff, Texas, generally described as USGS gage 08175000, and more particularly described as Latitude 29 degrees, 12 minutes, 54 seconds; Longitude 97 degrees, 26 minutes, 57 seconds.
(8) Guadalupe River at Cuero, Texas, generally described as USGS gage 08175800, and more particularly described as Latitude 29 degrees, 05 minutes, 25 seconds; Longitude 97 degrees, 19 minutes, 46 seconds.
(9) Guadalupe River at Victoria, Texas, generally described as USGS gage 08176500, and more particularly described as Latitude 28 degrees, 47 minutes, 34 seconds; Longitude 97 degrees, 00 minutes, 46 seconds.
(10) Medina River at Bandera, Texas, generally described as USGS gage 08178880, and more particularly described as Latitude 29 degrees, 43 minutes, 25 seconds; Longitude 99 degrees, 04 minutes, 11 seconds.
(11) Medina River at San Antonio, Texas, generally described as USGS gage 08181500, and more particularly described as Latitude 29 degrees, 15 minutes, 50 seconds; Longitude 98 degrees, 29 minutes, 26 seconds.
(12) San Antonio River near Elmendorf, Texas, generally described as USGS gage 08181800, and more particularly described as Latitude 29 degrees, 13 minutes, 19 seconds; Longitude 98 degrees, 21 minutes, 20 seconds.
(13) San Antonio River near Falls City, Texas, generally described as USGS gage 08183500, and more particularly described as Latitude 28 degrees, 57 minutes, 05 seconds; Longitude 98 degrees, 03 minutes, 50 seconds.
(14) Cibolo Creek near Falls City, Texas, generally described as USGS gage 08186000, and more particularly described as Latitude 29 degrees, 00 minutes, 50 seconds; Longitude 97 degrees, 55 minutes, 48 seconds.
(15) San Antonio River at Goliad, Texas, generally described as USGS gage 08188500, and more particularly described as Latitude 28 degrees, 38 minutes, 57.43 seconds; Longitude 97 degrees, 23 minutes, 05.49 seconds.
(16) Mission River at Refugio, Texas, generally described as USGS gage 08189500, and more particularly described as Latitude 28 degrees, 17 minutes, 30 seconds; Longitude 97 degrees, 16 minutes, 44 seconds.
Source Note: The provisions of this §298.380 adopted to be effective August 30, 2012, 37 TexReg 6629