Section 298.430 - Environmental Flow Standards(a) A water right application in the Nueces River 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 figure 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 paragraph (3)(A) - (C) of this subsection. (1) Impairment to the modeled permitting frequency shall be calculated individually for each inflow regime level in the figure located in paragraph (3) of this subsection for which a specific frequency is identified, at the point in the water availability model which represents inflows to Nueces Bay and Nueces Delta.(2) Impairment is calculated by subtraction of the values set out in paragraph (3)(A) - (C) of this subsection.(3) Bay and Estuary Freshwater Inflow Standards for Nueces Bay and Nueces Delta. Attached Graphic
(A) The modeled permitting frequencies for the target volumes for Level 1, as described in the figure located in paragraph (3) of this subsection, and calculated as a percentage of total months or years, as applicable, shall not be decreased by more than 50%.(B) The modeled permitting frequencies for the target volumes for Level 2, as described in the figure located in paragraph (3) of this subsection, and calculated as a percentage of total months or years, as applicable, shall not be decreased by more than 25%.(C) The modeled permitting frequencies for the target volumes for Level 3, as described in the figure located in paragraph (3) of this subsection, and calculated as a percentage of total months or years, as applicable, shall not be decreased by more than 10%.(D) Each season and year is independent of the preceding and subsequent seasons and years with respect to the calculation of the Target Volume, as described in the figure located in paragraph (3) of this subsection.(b) To the extent that strategies are implemented through a water rights permit or amendment to help meet the freshwater inflow standards for Nueces Bay and Delta, a water right application in the Nueces River 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 the figure located in subsection (a)(3) of this section, 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) Nueces River at Laguna, Texas, generally described as United States Geological Survey (USGS) gage 08190000, and more particularly described as Latitude 29 degrees, 25 minutes, 42 seconds; Longitude 99 degrees, 59 minutes, 49 seconds. Attached Graphic
(2) West Nueces River near Bracketville, Texas, generally described as USGS gage 08190500, and more particularly described as Latitude 29 degrees, 28 minutes, 51.9 seconds; Longitude 100 degrees, 14 minutes, 21 seconds. Attached Graphic
(3) Nueces River below Uvalde, Texas, generally described as USGS gage 08192000, and more particularly described as Latitude 29 degrees, 7 minutes, 25 seconds; Longitude 99 degrees, 53 minutes, 40 seconds. Attached Graphic
(4) Nueces River at Cotulla, Texas, generally described as USGS gage 08194000, and more particularly described as Latitude 28 degrees, 25 minutes, 34 seconds; Longitude 99 degrees, 14 minutes, 23 seconds. Attached Graphic
(5) Nueces River near Tilden, Texas generally described as USGS gage 08194500, and more particularly described as Latitude 28 degrees, 18 minutes, 31 seconds; Longitude 98 degrees, 33 minutes, 25 seconds. Attached Graphic
(6) Frio River at Concan, Texas, generally described as USGS gage 08195000, and more particularly described as Latitude 29 degrees, 29 minutes, 18 seconds; Longitude 99 degrees, 42 minutes, 16 seconds. Attached Graphic
(7) Dry Frio River near Reagan Wells, Texas, generally described as USGS gage 08196000, and more particularly described as Latitude 29 degrees, 30 minutes, 16 seconds; Longitude 99 degrees, 46 minutes, 52 seconds. Attached Graphic
(8) Sabinal River near Sabinal, Texas, generally described as USGS gage 08198000, and more particularly described as Latitude 29 degrees, 29 minutes, 27 seconds; Longitude 99 degrees, 29 minutes, 33 seconds. Attached Graphic
(9) Sabinal River at Sabinal, Texas, generally described as USGS gage 08198500, and more particularly described as Latitude 29 degrees, 18 minutes, 51.5 seconds; Longitude 99 degrees, 28 minutes, 49.7 seconds. Attached Graphic
(10) Hondo Creek near Tarpley, Texas, generally described as USGS gage 08200000, and more particularly described as Latitude 29 degrees, 34 minutes, 12.11 seconds; Longitude 99 degrees, 14 minutes, 51.68 seconds. Attached Graphic
(11) Seco Creek at Miller Ranch near Utopia, Texas, generally described as USGS gage 08201500, and more particularly described as Latitude 29 degrees, 34 minutes, 23 seconds; Longitude 99 degrees, 24 minutes, 10 seconds. Attached Graphic
(12) Frio River near Derby, Texas, generally described as USGS gage 08205500, and more particularly described as Latitude 28 degrees, 44 minutes, 11 seconds; Longitude 99 degrees, 08 minutes, 40 seconds. Attached Graphic
(13) Frio River at Tilden, Texas, generally described as USGS gage 08206600, and more particularly described as Latitude 28 degrees, 28 minutes, 02 seconds; Longitude 98 degrees, 32 minutes, 50 seconds. Attached Graphic
(14) San Miguel Creek near Tilden, Texas, generally described as USGS gage 08206700, and more particularly described as Latitude 28 degrees, 35 minutes, 14 seconds; Longitude 98 degrees, 32 minutes, 44 seconds. Attached Graphic
(15) Atascosa River at Whitsett, Texas, generally described as USGS gage 08208000, and more particularly described as Latitude 28 degrees, 37 minutes, 19 seconds; Longitude 98 degrees, 16 minutes, 52 seconds. Attached Graphic
(16) Nueces River near Three Rivers, Texas, generally described as USGS gage 08210000, and more particularly described as Latitude 28 degrees, 25 minutes, 38 seconds; Longitude 98 degrees, 10 minutes, 40 seconds. Attached Graphic
(17) Nueces River near Mathis, Texas, generally described as USGS gage 08211000, and more particularly described as Latitude 28 degrees, 02 minutes, 17 seconds; Longitude 97 degrees, 51 minutes, 36 seconds. Attached Graphic
(18) Oso Creek at Corpus Christi, Texas, generally described as USGS gage 08211520, and more particularly described as Latitude 28 degrees, 42 minutes, 40 seconds; Longitude 97 degrees, 30 minutes, 06 seconds. Attached Graphic
(19) San Fernando Creek at Alice, Texas, generally described as USGS gage 08211900, and more particularly described as Latitude 27 degrees, 46 minutes, 20 seconds; Longitude 98 degrees, 02 minutes, 00 seconds. Attached Graphic
30 Tex. Admin. Code § 298.430
The provisions of this §298.430 adopted to be effective March 6, 2014, 39 TexReg 1416