LCRA Griffith League Ranch Application (2018)

Location of LCRA’s Proposed Wells on Griffith League Scout Ranch, Bastrop County, TX (click map for larger view)

The Lower Colorado River Authority (LCRA) applied with the Lost Pines Groundwater Conservation District (District) for groundwater operating and transport permits for eight (8) wells, for a total combined maximum annual production of up to 25,000 acre-feet/year on February 21, 2018.  The LCRA acquired groundwater rights in the Simsboro and Carrizo-Wilcox aquifers under the approximately 4,847 acre Griffith League Ranch (GLR) property in Bastrop County on January 9, 2015 by Warranty Deed.  LCRA requested the permits include a phased approach to increase authorized pumping over time with Phase 1 total combined maximum annual production up to 8,000 acre-feet/year, Phase 2 15,000 acre-feet/year and Phase 3 25,000 acre-feet/year.

LCRA claims it has existing firm contractual commitments in excess of 400,000 acre-feet/year for a variety of beneficial uses, including municipal, industrial, recreation, irrigation/agricultural and instream uses. With few exceptions LCRA claims that the contractual commitments generally provide that LCRA may meet its obligations from any source available to LCRA.

The map on the right shows the location of the proposed well-field site in Bastrop County, TX.  The well-field is approximately northeast of FM1441 and northwest of HWY 21 going northeast out of Bastrop.

Schedule for Public Hearing and Deadline for Registering Objections

The District has indicated the tentative schedule posted earlier is no longer an option.  They are in the process of working with the Applicant to schedule sometime in the mid to late summer.  We will keep you posted as we get more definitive information.

For more information on requesting a contested case hearing review Rule 15.1.E on page 41 of the District’s Rules.

Environmental Stewardship will attempt to notify persons who have signed up for our Newsletter  about the date, time and other details regarding the above meetings and dates (see “Sign Up For Our Newsletter” below).

 

The maps below show the other commercial, non-exempt well fields near the LCRA Griffith Ranch project (left) and the drawdown in the Simsboro aquifer that is predicted to result from the pumping of 25,000 ac-ft/year over a period of 50 years by the same project (right).  (Source: Review of LCRA Permit Application Packet).

Unfortunately the Groundwater Conservation District considers the pumping from each well field on an individual basis and only for the target aquifer (Simsboro) that is being pumped.  The District does not consider the impact of the combined pumping from all of the well fields on surface water, the other aquifers that communicate with the target aquifer, nor do they specifically consider the impact of the pumping on shallow exempt domestic wells.

Project specific 50-year drawdown (in feet) in the Simsboro Aquifer attributable to the proposed LCRA pumpage estimated using the GAM. (click map for larger view).

Location of large non-exempt well fields in proximity of the LCRA Griffith League Ranch Groundwater permit application (click map for larger view).

 

According to the District’s analysis, the model run results indicate that at the end of 40 years of pumping (in 2060), the project-specific drawdown (drawdown due to the proposed LCRA wells only) is as follows:

  • approximately 225 to 250 feet at the three Aqua well locations (McDade, Behrend, and Highway 21).
  • approximately 250 to 275 feet at the proposed “Recharge” (End Op) well locations.
  • approximately 160 to 180 feet at the existing LCRA wells near Lake Bastrop.

In comparison, the combined pumping of the Aqua, Recharge, LCRA, and Vista Ridge pumping — not including the LCRA Griffith Ranch project — are predicted to cause drawdowns in the Simsboro Aquifer of 900 – 1200 feet by 2060. See study below.

A recent study predicts that the combined pumping of the Simsboro Aquifer will impact other shallower aquifers in the Carrizo-Wilcox Group.  THE STUDY DID NOT INCLUDE THIS LCRA GRIFFITH LEAGUE RANCH PROJECT. 

Contour map of drawdown resulting from Simsboro pumping

The combined pumping in the Simsboro Aquifer is predicted to cause 900 to 1200 feet of drawdown in the Simsboro Aquifer in Burleson and Lee counties by the year 2060 according to groundwater modeling conducted by professional hydrologist George Rice.  The combined groundwater pumping within Lost Pines and Post Oak Savannah Groundwater Conservation Districts (GCD) are predicted to impact not only the Simsboro Aquifer, but also the Carrizo, Calvert Bluff and Hooper aquifers extending to points as far away as Gonzoles, Lavaca, Colorado, Austin, Grimes and Walker counties.   These aquifers are hydraulically connected throughout the Carrizo-Wilcox Aquifer Group.

Click here for more information on the impacts of the combined Simsboro Aquifer Pumping.
Click here for Rice Report March 22, 2016

Leakage from the Carrizo, Calvert Bluff, and Hooper aquifers

According to the Rice report, the effects of the pumping would not be limited to the Simsboro Aquifer. The pumping would induce leakage from the Carrizo, Calvert Bluff, and Hooper aquifers. This leakage would reduce hydraulic heads in the aquifers. Where the aquifers are confined, the reduction in heads would reduce water levels in wells that draw water from the aquifers. Where the aquifers are unconfined (the shallow outcrop areas where many domestic wells are located), the reduction in heads would dewater portions of the aquifers. The position of these aquifers relative to the Simsboro is shown in figure 1.

Figure 1.  Geologic Units Represented in the GAM
(adapted from TWDB, 2004, figure 5.1) (Click image for larger view).

Leakage is a common and well-known phenomenon that is discussed in standard hydrology texts[1]. In figure 1, leakage (cross-formational flow) between geologic units is indicated by double-headed arrows. In a 2009 pump-test conducted in Lee County, it was estimated that 22% of the water pumped from the Simsboro was derived from leakage from adjacent aquifers[2].

Depending on where a Landowner’s property is located in the outcrop, the aquifers beneath the property will be the ones listed below the location.   For example, if the property is in the Carrizo outcrop, the aquifers below the property are the Wilcox/Calvert Bluff, Wilcox/Simsboro, and the Wilcox/Hooper; in that order.   A landowner owns the groundwater beneath his/her property in ALL of those aquifers.

[1]See, for example, Davis and DeWiest 1966, pages 224 – 229; and Freeze and Cherry, 1979, pages 320 – 324.

[2]Thornhill 2009, page 8.

The maps below show the approximate location of the LCRA Griffith League Ranch Project over the Carrizo, Calvert Bluff, Simsboro, and Hooper Aquifers.

The LCRA Griffith League Ranch Project is likely located in the Carrizo and/or Calvert Bluff aquifer outcrops. Landowners should find the general location of their property and wells on the maps below to be able to estimate the feet of predicted drawdown under their property within the 50 year planning period.

                Click on each map to see a larger view of the map.