Groundwater Concerns in Bastrop and Lee Counties

Environmental Stewardship fully embraces the desired future conditions (DFC) process established by HB 1763 and believes this is one of the most important steps in establishing a water management plan that provides for our future water needs while protecting the water and other natural resources of the region. The desired future conditions (DFCs) for GMA-12 are currently under review and proposed DFCs are under consideration for adoption.   ES has provided extensive written comments on the current review process and the proposed DFCs.

We are at a critical juncture in the State planning process where it is the duty and responsibility of groundwater conservation districts (GCD), groundwater management areas (GMA), and the Texas Water Development Board to accurately estimate the amount of groundwater available in the future so regional planning groups like the Lower Colorado and Brazos Regional Water Planning Groups (Regions K and G respectively) can accurately plan to meet water demands.  Our local groundwater conservation district is the Lost Pines GCD, which is in groundwater management area 12 (GMA-12).

Three Issues of Concern:
There are currently three major issues that have major implications for the long-term economic and ecological health of the Lost Pine Region and the Colorado River and tributaries.

Over-pumping due to local over-use
The following graph depicts the cumulative effect of the water demand versus groundwater availability as reflected in Region K’s current planning. Lost Pines GCD has indicated that they are using these demand values to set their desired future condition rather than using recharge rates. It appears the use of these demand estimates leads to an erroneous, and likely over-estimate of groundwater availability and over-pumping of the aquifers; an unsustainable scenario.

A gross over-estimation of the groundwater available at this juncture will cause crisis in future years if the amount of groundwater expected is not available. It will be very difficult for our cities and communities to find other sources of water if they have already installed infrastructure and made contracts for groundwater that is not really available. If, as the models predict, pumping in the Carrizo-Wilcox and related aquifers start damaging base-flows to the Colorado and Brazos rivers, and the streams, creeks and springs in our region, groundwater districts will be hard pressed to take corrective actions unless they have included the protection of these very valuable natural resources in the desired future conditions and rules. (Excel File)

This graph shows the quantity of pumping and the quantity of groundwater supplied to the Colorado and Brazos rivers and streams by the Carrizo-Wilcox and related aquifers from 1980-1999. The graph shows that the water supplied to rivers, streams and springs declined by 50% while the amount of pumping increased by 31%. This data was extracted from a presentation by Bill Hutchinson of the Texas Water Development Board to the Lost Pines Groundwater Conservation District on November 18, 2009. The data were taken from the Groundwater Availability Model calibration run for the GMA-12 area in anticipation of establishing the desired future conditions for the area. This is a significant change in the relationship between groundwater and surface water. The anticipated impact on the Colorado River is likely a predictor of a significant change in the ecological relationships as over-pumping accelerates in the region over the next 20-50 years.

By including river and stream base-flows and spring flows in the planning at this juncture more accurate estimates can be made on the amount of groundwater that can be made available without damaging these resources. Regions K and G will then have more reliable groundwater estimates to use in their current and future planning processes and will not be caught short at some time in the future.

Therefore, our request is two-fold:

  • Protect the rivers, streams and spring that depend on groundwater, and
  • Provide our water planners with the best estimates possible.

The following linked information demonstrates that:
A. There is adequate quantitative data on the Colorado River and Springs,
B. Over-pumping threatens the groundwater-surface water relationship,
C. Groundwater models make adequate provision for rivers, streams and springs,
D. Flow measurement technology exists to quantitatively monitor river & spring flows, and
E. Groundwater districts have a duty to protect both groundwater and surface water resources.

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