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Region L - South Central Texas
2005 Regional Water Plan Review

The following general review is based on the 2005 Initially Prepared Regional Water Plan (IPP).
Regional Facts
 Major Cities | San Antonio, Victoria |
| Population: 2000 | 2,042,221 |
| Population: 2060 | 4,297,786 |
| Total Water Use: 2000 | 896,353 Acre-Feet |
| Total Water Use: 2060 | 1,273,003 Acre-Feet |
| Primary Rivers | Guadalupe, San Antonio, Nueces, Lavaca-Guadalupe, San Antonio-Nueces |
| Major Aquifers | Edwards (BFZ), Trinity, Carrizo-Wilcox, Gulf Coast |
| Annual Precipitation | 20-44 Inches |
| Net Evaporation | 28-56 Inches |
Basic Plan Facts
- Population in the region is projected to more than double between 2000 and 2060
- Total capital cost of water supply measures: Not Available
- Off-channel reservoirs and diversions on the Lower Guadalupe and Lower Colorado Rivers are proposed
- Proposed groundwater strategies result in long-term drawdown of water levels in aquifers
- The Plan proposes projects significantly in excess of projected needs.
What's at Issue?
The San Antonio area faces major challenges because of the need to reduce dependence on the Edwards Aquifer in order to protect spring flows at Comal and San Marcos Springs and associated endangered and threatened species.
Several proposed water development projects could have significant effects on more of the principal rivers and associated bay and estuarine systems of our State. Components of the Region L plan have the potential to affect the ecological health of not only the San Antonio and Guadalupe Rivers but also the Colorado, Nueces, and Lavaca-Navidad Rivers. The plan also could have affects on several of the major estuarine systems of Texas: San Antonio Bay (Guadalupe Estuary), Corpus Christi (Nueces Estuary) and Matagorda Bays. A prominent example is the proposed Guadalupe River Diversion to San Antonio. This strategy would include serious reductions in freshwater inflows to the Guadalupe estuary, and threatens endangered Whooping Cranes at the Aransas National Wildlife Refuge. The San Antonio Water System has dropped their participation in the Guadalupe River Diversion Project. The Region L Planning Group has yet to remove the Project from the Plan however.
Groundwater projects in the Plan are projected to result in long-term drawdowns in the Trinity, Carrizo, and Gulf Coast Aquifers. These drawdowns could result in decreased springflow, decreased baseflow to rivers and estuaries, and increased pumping cost for local groundwater users. In some instances, the proposed volumes of pumpage from the projects exceed the recommendations of local groundwater control districts.
Action Items
Here are some of the items the Region L Planning Group must address.
Conservation and Drought Management
For conservation and drought management, the plan needs to...
- Implement Irrigation Water Conservation Strategies. The plan assumes that irrigation conservation is being practiced to the extent feasible, despite the fact that 720,000 additional acres are not irrigated with center pivots.
- Recognize the full potential for municipal conservation. The municipal conservation goal in the plan is the existing average of 172 gpcd (gallons per capita per day), well above the 140 gpcd recommended by the State Water Conservation Implementation Task Force.
- Incorporate drought management as a water management strategy. Not considering existing local statutory limitations on non-essential water use during times of drought inflates demands that can lead to an overemphasis on costly water projects.
Environmental Flows
To secure the protection of flows for fish and wildlife, the plan needs to...
- Include environmental water needs as a specifically recognized category of water demand that must be planned for.
- Include in the discussions the numerous other springs in the area that have wildlife and ecological importance.
- Designate stream segments in the region that meet the criteria as having "unique ecological value". No segments were designated in the 2006 regional plan. The Texas Parks and Wildlife Department recommends 20 segments for designation in this region.
Economics
To ensure that only the most economically sound water supply strategies are implemented, the plan needs to...
- Recommend specific projects for meeting only the projected need. The Plan proposes projects that supply over 800,000 acre-feet/year, yet projected demands are only 417,000 acre-feet/year.
Online Resources
Regional water plan documents can be located on the TWDB website.
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One strategy proposed to meet water demands of Corpus Christi (Region N) would withdraw 9 billion gallons of water a year from the Gulf Coast Aquifer in Refugio County and pipe it to Corpus Christi. These withdrawals would lower the aquifer level by 200 feet over the next 50 years, potentially leading to saltwater intrusion and land surface subsidence. Given that Corpus Christi has overestimated its water use by 25 to 45 % in the State Plan, this project is unnecessary.
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Limits on Water Use May Come Earlier
San Antonio Express News, 12/2008
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Drying on the Vine, Water shortage forces family farms into survival mode
The Austin Chronicle, 11/20/2008
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Too Many Straws in the Well
The Austin Chronicle, 11/20/2008
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Regional cooperation on water planning benefits all
San Antonio Express-News, 11/13/2008
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Not enough water for growing population
The Boerne Star, 9/30/08
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Facing a water 'calamity'
Boerne Star, June 2008
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Flowing, but slowing: River signals need for rain - and conservation
San Marcos Daily Record, 5/17/2008
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Drought-plagued Georgia to get insight from SAWS
San Antonio Express-News, 5/16/2008
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Boerne ISD making water work
San Antonio Express-News, 4/21/2008
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New water facts revealed
The Gonzales Inquirer, 4//2008
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Editorial: SAWS' rough waters concern whole city
San Antonio Express-News, 4/07/2008
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Between the Lines by Greg Little
The Gonzales Inquirer, February 2008
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Is there enough water to go around?
Victoria Advocate, 12/20/2007
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SAWS project estimated cost rises
Bay City Tribune, 11/12/2007
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sustainability
Sustainable management is maintaining a constant amount of water in the aquifers. This means that average withdrawals do not exceed a rate which can be replenished through recharge on a continual basis while maintaining adequate outflows, such as base and springflows, from the aquifer.
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