Updated water plan for Hill Country development meant to protect Texas' 'crown jewels'

TRAVIS COUNTY, Texas (KXAN) — After several months, the West Travis County Public Utility Agency (WTCPUA) released the updated water plan for a Texas Hill Country development on Wednesday morning.

On Monday, the WTCPUA agreed in a unanimous decision to move forward on a proposed water service line to the Mirasol Springs development, which is located just west of Hamilton Pool. The new water line is meant to help prevent groundwater depletion in the area surrounding what some in the area call the "crown jewels" of Texas.

The original service agreement was filed in September.

This agreement was updated at the board meeting on Nov. 18, 2024, with additional provisions.

“There’s both good and not so good. But we’re making progress,” landowner Lew Adams said after the decision was made by the board. Adams owns land that is surrounded by the Mirasol Springs development.

According to the agreement, Mirasol Springs will enter into a contract for 347 Living Unit Equivalents (LUEs). One LUE, according to the WTCPUA's website, is equal to 450 gallons per day of water.

The developer, Mirasol Capital, will be required to pay for the installation of the water line, which will run from an access point west of Highway 12 at the Peacock Ranch development, down Hamilton Pool Road and to the development. The line will start at four inches in diameter and shrink to three inches at the development.

Water from the utility agency must be the exclusive water source for the project. Previous drafts have labeled this "potable" water, but the new version has crossed this out.

No groundwater or surface water can be used as a water source, according to the letter.

Major changes to the water line agreement

At the board meeting Monday, several major changes were added to the letter.

The Mirasol developers will agree not to drill new groundwater wells and include a plat note prohibiting new wells. In the meeting, board president Scott Roberts said that this "plat note" will ensure that this restriction sticks with the property no matter who owns it.

The WTCPUA will inspect the development and if they find a violation on groundwater use, they will provide a 60-day notice for the development to fix the issues. If it is not fixed, the developer will lose water service until a correction is made.

The current Phase 1 irrigation plan for the development's farm must be abandoned. The WTCPUA will instead provide water for irrigation. This service will also extend into Phase 2.

Finally, the developer must agree to limits in their TLAP (Texas Land Application Permit). These TLAPs manage wastewater disposal. The wastewater must have Total Nitrogen and Total Phosphorous levels to one parts per million. This means wastewater must be treated to drinkable levels.

Mirasol Springs will decide if they will agree to the new terms in 30 days. The full contract can be read below:

Mirasol Springs and conservation

Mirasol Springs aims to set the “gold-standard” for developers in the future, with several green initiatives in place meant to protect the environmentally sensitive land it is scheduled to be built on.

That land, just west of Hamilton Pool and Reimer’s Ranch along the Pedernales River, is dotted by several springs. Activists and landowners worry that development in the area could lead to groundwater depletion and that these springs could dry up.

Travis County Commissioner’s Court, who initially voiced concerns about the impact of the development on the springs, has since come out in favor of the water line under several restrictions.

• The size of the water main line extension shall not exceed 3 inches with a maximum flow of 108 gallons per minute.
• The drilling of any new water wells and, upon service from the WTCPUA, the non-exempt
  use of groundwater is prohibited.
• Rainwater harvesting and storage for outdoor irrigation is mandatory.
• The use of the Pedernales River as a potable water supply to the area served by WTCPUA is
  prohibited.
• Mirasol will sever its groundwater estate and grant Travis County a groundwater conservation easement.
• WTCPUA water is limited to indoor use.

Ahead of the Mirasol vote in October, representatives with the WTCPUA told KXAN that “the reason we are considering it is to relieve capacity from the Trinity Aquifer and the Pedernales River.”