Table 3-1.
Groundwater Availability by Aquifer
South Central Texas Region

		Annual Quantity Available
Aquifer Name and TWDB Aquifer No.^1	1990 Use (acft)	2000 (acft)	2010 (acft)	2020 (acft)	2030 (acft)	2040 (acft)	2050 (acft)
Edwards (11)	519,459	340,000	340,000	340,000	340,000	340,000	340,000
Carrizo (10)^2	279,484	304,484	304,484	304,484	168,159	168,159	168,159
Sparta (27)	47,060	47,060	47,060	47,060	47,060	47,060	47,060
Queen City (24)	18,003	18,003	18,003	18,003	18,003	18,003	18,003
Trinity (28)	9,563	9,563	9,563	9,563	9,563	9,563	8,207
Gulf Coast (15)	89,668	89,668	89,668	89,668	89,668	89,668	89,668
Edwards-Trinity (Plateau)^3 (13)	4,090	4,090	4,090	4,090	4,090	4,090	4,090
Total	967,327	812,868	812,868	812,868	676,543	676,543	675,187
Percent of Total
Edwards (11)	53.70%	41.83%	41.83%	41.83%	50.26%	50.26%	50.36%
Carrizo (10)	28.89%	37.46%	37.46%	37.46%	24.86%	24.86%	24.91%
Sparta (27)	4.86%	5.79%	5.79%	5.79%	6.96%	6.96%	6.97%
Queen City (24)	1.86%	2.21%	2.21%	2.21%	2.66%	2.66%	2.67%
Trinity (28)	0.99%	1.18%	1.18%	1.18%	1.41%	1.41%	1.22%
Gulf Coast (15)	9.27%	11.03%	11.03%	11.03%	13.25%	13.25%	13.28%
Edwards-Trinity (Plateau)^2 (13)	0.42%	0.50%	0.50%	0.50%	0.60%	0.60%	0.61%
Total	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%
^1TWDB aquifer identification number is shown in parentheses in column number 1. ^2Underground Water Conservation Districts in the Carrizo Aquifer Area have adopted policies to limit annual pumping to estimated annual recharge. ^3Edwards-Trinity (Plateau) Aquifer.

Source: *File 12—Groundwater Supplies, Ixxxx-17.txt, Texas Water Development Board, January, 1998.