Article Written By: Zane Liston
Engineers are now mapping Hays County’s water future…again. In a public forum at the Wimberley Community Center, over 50 people gathered to meet the engineers leading the study and to give their input on the study’s scope and importance.
Hays County hired engineering firm HDR earlier this year to build on a history of collaboration on water studies. HDR’s 1989 Hays County Regional Water and Wastewater Study and its 2011 Water and Wastewater Facilities Plan, provide a window into the changes in technology, water availability, and mindset over many decades. This year, the update seeks to provide an answer to the question that’s growing even more urgent: Does western Hays County have enough water to support the people already living here, in the face of hundreds of thousands more people expected to arrive, based on state population projections?
According to the engineers at the public meeting in Wimberley last month, the short answer is that the math is getting very tight, along with the timeline. It can take ten years or more to develop a new water supply project, or even more time to conserve and diversify enough to offset the strain. The city is facing the pressure head-on. The Texas General Land Office’s Resilient Communities Program has offered state funds for the Wimberley Valley to plan with resilience in mind, funding the new Comprehensive Plan as well as the One Water Study for the city. This year’s planning processes are going to be significant and visionary as we move forward.
The importance of the HDR Study:
Hays County Commissioners Court approved the study in January as an update to a county-wide water assessment last completed in 2011. Tremendous growth has happened over the last 14 years; Hays County has grown by roughly 40%, and San Marcos alone has added over 41,000 residents. State projections suggest the county could eventually grow from its current population of around 280,000 people to nearly 1.4 million people by 2070. Most of the population growth is projected along the I-35 corridor, according to the 2027 State Water Plan from the Texas Water Development Board.
The study, conducted by HDR Senior Client Manager Darren Thompson and Water Resources Project Manager Kelsey Cayeros, involves four public meetings across the county’s precincts, with follow-up meetings in the Fall. The Wimberley session, last April, was the first of these public meetings.
Water has always been a defining issue across Hays County, drawing concern from constituents, city councils, and Hays County Commissioners. Residents and stakeholders have consistently raised questions about how the region is responding to prolonged drought. Even under Stage 4 restrictions, and with some community members conserving aggressively, new subdivisions continue to be approved and built. That tension points to a larger question: whether the region’s long-term goals are aligned with its current pace of growth and pattern of development.
Water concerns are wide-ranging. Well owners worry about declining water tables. Ratepayers at local utilities face rising costs and uncertain supply. Communities whose livelihoods and identities are tied to the springs and creeks are seeing those resources and our economy under continual strain. This study is intended to address these concerns and provide a technically vetted, impartial foundation for residents, utilities, well owners, and local governments to make better-informed water management decisions for our community.
Survey question: What are the biggest challenges of our region?
The current state of our water:
Western Hays County, including the Wimberley area, relies almost entirely on groundwater. Unlike eastern parts of the county, which have access to surface water and regional supply lines, communities here are drawing from the same aquifer that has been under stress for years.
The numbers from local water providers tell an interesting story. Wimberley Water Supply Corporation has seen production fall 37% since 2003, and Aqua Texas saw a 17% decrease in just the past year. Meanwhile, population projections used in regional water plans, estimating between 3,000 and 25,000 residents, appear well below what’s actually happening on the ground, because state planning tools for growth aren’t particularly localized. As some water providers are attempting to stay afloat and reduce strain on the aquifer, exempt wells continue to create a true blind spot in regional planning. Without intervention, there’s a real risk that our policies enable the kind of overdevelopment our community opposes.
This HDR study, with community participation, is an opportunity to craft policy that reflects the true character of our community. Most residents favor balanced, measured growth, a ‘shut the gate’ mentality focused on protecting the Valley’s nature for future generations. This was the strongest sentiment voiced to the engineers in April.
David Glenn, a longtime Wimberley resident and advocate, brought his heavily annotated copy of the 2011 study. He said, pointing at the map of growth since then in Dripping Springs, “at the time, we talked about ‘water supply resources’. But the people here are interested in tourism, and quality of life. They’re interested in becoming a ‘bedroom community’ [of Austin] versus a little bit of heaven. We live in a little bit of heaven”.
[Click Here to Read the Full Study]
[Click Here to Read David Baker’s 2011 Comments]
Solutions Being Explored in the HDR Study:
The study has five main components. The first is a high-level look at all of the county’s water providers, mapping who they are, how much they supply, and what their permits allow. The second, most relevant to this area, is a localized water supply plan focused specifically on Wimberley Water Supply Corporation and Aqua Texas. HDR is meeting with both utilities to understand their current customer base, usage patterns, and how they plan to meet future demand for water and wastewater across southwestern Hays County.
The third component involves flood risk mapping: and this is where community input matters greatly. HDR is collecting local knowledge about roads that flood regularly, especially any that serve as sole access to neighborhoods. Projects that get incorporated into the state flood plan can qualify for grants and low-interest loans, so having local roads and crossings identified is a benefit to everyone.
The study also includes an infrastructure assessment for some areas and a review of county development ordinances to see how they interact with water and flood concerns. The study’s findings are expected to inform subdivision regulations currently under review by the county.
Engineers outlined a range of options being evaluated, from the near-term to the ambitious. Conservation and efficiency improvements are the most immediate lever, and rigorous water loss audits for utilities could identify where water is leaking before it even reaches customers. Reclaimed water systems (sometimes called “purple pipe”) could allow treated wastewater to be reused for irrigation and other non-drinking purposes, reducing demand on the aquifer.
Longer-term options include aquifer storage and recovery (ASR), connections to regional water supply systems like the LCRA or GBRA, and even direct potable reuse — treating wastewater to drinking-water standards. These options are more expensive and complex, and need to be carefully weighed and studied for the right fit for our community.
Local citizens commenting at the forum raised additional ideas, including rainwater harvesting incentives for homeowners and developers, better tracking of bulk water deliveries to understand how many households rely on water trucking, and coordination with private well owners, a significant but hard-to-count portion of the local population. There was even talk of expanding the scope of the study to encompass private and exempt wells in predictions around future supply. While some of these points were outside of the scope of the study, the community was insistent that these are instrumental pieces of the puzzle.
Next Steps for the Study:
The study runs through December 2026. Final results will feed into regional water plans, which in turn affect eligibility for state and federal funding. Commissioner Morgan Hammer, who introduced the forum, emphasized that the study is also intended to give the county data it needs to make the case to state legislators for expanded regulatory authority, particularly for the Hays County Groundwater Conservation District, which currently has less oversight power than most districts in Texas, but is the one entity that gathers data and manages our natural resources so they remain for future generations.
Residents who want to weigh in can attend one of the remaining precinct meetings this season, submit written comments, or watch for future opportunities as the study progresses in the fall. Presentation materials are being made available online on the County’s website.
The Watershed’s Perspective
In his comments on the 2011 HDR Water & Wastewater Plan, and again 15 years later as the County updates the document, David Baker, founder and Executive Director of the Watershed Association, praised HDR’s data collection and acknowledged that real progress has been made, but warned that the plan rested on a high-growth scenario and an unsustainable 30-foot aquifer drawdown that amounts to “mining” the Trinity, a policy he argued conflicts with the Hays Trinity Groundwater Conservation District’s mission and would diminish springflows at Jacob’s Well, Blue Hole, and the Blanco River.
Additionally, in 2026, Baker noted that the intervening years of drought and overpumping had borne out those warnings, most starkly in Jacob’s Well, averaging zero flow for years at a time, and leaving nearly all of his original concerns still relevant and unaddressed. Rather than building nearly half a billion dollars in new infrastructure to chase projected demand, he urged the County to manage growth proactively through aquifer recharge infill, conservation development standards, required rainwater harvesting, decentralized wastewater reuse, and large-scale land conservation, while capping Trinity pumping at sustainable levels and holding public water suppliers accountable to strict conservation and line-loss standards. He questioned costly imported-water pipelines as short-term fixes, called for no major Hill Country pipeline investment without a citizen vote, and recommended the County pursue a regional, publicly owned water system, including acquiring the Aqua Texas system in Wimberley, to keep local water under local control. Above all, Baker pressed for broader public participation, an adaptive plan updated regularly, and a commitment that the water security and quality of life of existing residents not be sacrificed to accommodate uncertain future growth.
Further reading:
“County gathers public input as water study moves forward”, The Wimberley View
“Hays County approves first water study in 15 years”, The University Star