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Region K - Lower Colorado
2005 Regional Water Plan Overview
Regional Facts
Major Cities | Austin |
| Population: 2000 | 1,132,228 |
| Population: 2060 | 2,713,905 |
| Total Water Use: 2000 | 1,004,335 Acre-Feet |
| Total Water Use: 2060 | 1,301,682 Acre-Feet |
| Primary Rivers | Colorado |
| Major Aquifers | Trinity, Edwards (BFZ), Carrizo-Wilcox, Gulf Coast |
| Annual Precipitation | 24-48 Inches |
| Net Evaporation | 20-44 Inches |
Basic Plan Facts
- Population is projected to more than double between 2000 and 2060
- Water use is projected to increase by 30%
- Total capital cost of proposed water supply measures: $256 million
- Two minor reservoirs proposed: Goldthwaite Channel Dam and Off-channel Reservoir
- A major diversion project of 150,000 acre-feet/year and four "ring dike" reservoirs proposed to meet needs in Region L (San Antonio)
- Transfer of 25,000 acre feet of water out of basin to Williamson County annually
What's at Issue?
The protection of bay and estuary inflows is particularly relevant for Region K due to the importance of the Matagorda Bay estuary to the economy and quality of life of the region. Potential impacts from proposed strategies in the 2006 regional plan to the freshwater inflows to Matagorda Bay could be devastating to the region's wildlife and the coastal economy. These proposed strategies are the result of the increasing pressure that population growth in this region, and in its neighboring region (L), is putting on the limited water supplies of Central Texas.
The Region puts a heavy emphasis on Municipal Water Conservation to meet needs, but does not go the extra step of recommending conservation to get per capita consumption below 140 gallons per capita per day. Region K does recommend that entities that do not have a water supply shortage go ahead and put a good water conservation plan in place in order to stretch the water supplies for the entire region.
There is an emphasis on agricultural conservation measures, especially with rice farming. This is important given that rice farming is the largest user of water in the Lower Colorado River Basin. Unfortunately, the measures do not stand alone, but are tied to the success of a specific proposed strategy - the transport of water from the Colorado River to San Antonio (49 billion gallons per year).
The planning group did a poor job of evaluating the impacts of its chosen water management strategies of the environment. This is a requirement of the plan.
Action Items
Here are some of the items the Region K Planning Group must address.
 Conservation and Drought Management
For conservation and drought management, the plan needs to...
- The group has done a good job of including recommendations for advanced municipal conservation throughout the region and counting that conservation towards meeting water needs. However the group did not go the extra step of counting advanced municipal conservation below 140 gpcd toward meeting the municipality's needs.
- Although a sustainable approach to the use of groundwater in the region was adopted by the group, the LCRA-SAWS project relies on large withdrawals from the Gulf Coast Aquifer (the groundwater pumping associated with the LCRA-SAWS project is not sustainable as defined by the RWPG). This pumping is proposed without addressing impacts on baseflow of the Colorado River and other streams.
- The plan does not include drought management as a water management strategy. Each water user group with a shortage should use a drought management strategy derived from its drought management plan as a way to meet their water needs. The regional plans in the state are based on a drought of record and it only makes sense that drought management should play a large role in planning to meet the region's water needs during that drought period.
Environmental Flows
To secure the protection of flows for fish and wildlife, the plan needs to...
- Fully assess how environmental flows are affected by current and proposed projects and existing and proposed water permits. Ensuring the Matagorda Bay and estuary inflow needs and in-stream flow needs below Lake Travis will be met require careful management of releases from the lakes in the Austin region. The proposed diversion of water to San Antonio could reduce freshwater inflows down to only 51% (or less) of critical levels during the driest years. Adequate flows are critical to the tourism and fishing industries along the coast. There should be a meaningful quantitative environmental analysis of the LCRA-SAWS project and other proposed strategies in the plan.
- The City of Austin is planning on reusing its wastewater in increasing quantities. There needs to be an evaluation of the environmental impacts of this and the impacts to downstream water rights holders. The environmental analysis should compare the reuse strategy to current conditions rather than the drought of record/no return flows scenario used in the plan in order to get meaningful results.
- Include information on the nature of the springs in the region and the habitats they support.
Water Availability Modeling
- The Lower Colorado Regional Water Planning Group and the Region F Region Water Planning Group had issues with the water availability in the last few months of the planning process. Both groups had drastic changes in the amount of available water in their respective regions when compared to the last planning cycle. The groups worked through this by coming up with a quasi-subordination agreement between the 2 regions. The RWPG needs to address any problems with the newer version of the WAM and use that as the foundation of the plan. This needs to be done is a transparent manner.
Economics
To ensure that only the most economically sound water supply strategies are implemented, the plan needs to...
- Compare the costs and benefits of the supply alternatives in a consistent and reasonable manner.
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Region K