Introduction
Water scarcity growth is no longer an abstract planning issue in the San Antonio-Hill Country region; it is now a defining reality shaping infrastructure, development, and long-term quality of life.
You can widen a road. You can approve another subdivision. You can build another shopping center. Water is different.
At some point, the numbers stop being theoretical. They stop being a topic for water planners, engineers, and city managers, and they become a reality for everyone else. As I write this on March 17, 2026, the Edwards Aquifer Authority has the San Antonio Pool in Stage 4, requiring a 40 percent reduction for regulated permit holders. Canyon Lake is 59.6 percent full. Medina Lake is 4.1 percent full. Those are not minor warning signs. They are a snapshot of a fast-growing region trying to push ahead while the foundation under its water system is under obvious strain. [1][2][3]
That is what this article is about. Not panic. Not politics. Not a simplistic “we’re running out of water tomorrow” argument. This is about understanding how the San Antonio–Hill Country water system actually works, why Boerne and Fair Oaks Ranch are tied into a much bigger regional picture, why Canyon Lake and Medina Lake are not interchangeable, how 25 years of population growth changed the math, and why the next 25 years will almost certainly force harder choices and more expensive solutions. [4][6][21][22]
Water in This Region Is Not One Thing
One of the biggest mistakes people make is talking about “water” as though it comes from one place and moves through one pipe. It does not.
In this region, water is accumulated through rainfall, streamflow, reservoir capture, aquifer recharge, and increasingly through imported or highly treated supplies. It is stored above ground in lakes and reservoirs, below ground in aquifers, and in some cases intentionally underground through aquifer storage and recovery. It is then treated, pumped, blended, stored again in tanks, and distributed through local and regional networks. That is why a discussion about the Edwards Aquifer cannot be separated from Canyon Lake, why Canyon Lake cannot be separated from GBRA treatment capacity, and why local growth in Boerne or Fair Oaks Ranch cannot be isolated from what is happening across the broader San Antonio metro and Hill Country corridor. [4][5][6][9]
The Edwards Aquifer Is Still the Backbone, but It Is Not a Blank Check
The Edwards Aquifer remains the backbone of the regional water system. It is one of the most productive aquifers in the country, and its geology is what makes it both remarkable and fragile. It is a karst limestone system full of fractures, faults, conduits, sinkholes, and solution channels. Water can move through it fast. Recharge can happen quickly when the right rains fall in the right places. But that same setup also means it is highly dependent on hydrology, recharge-zone conditions, and stream losses across the outcrop. Government and academic sources have long noted that most Edwards recharge comes from streams crossing the recharge zone, not simply from rain falling neatly into a static underground reservoir. [4][5]
That matters because many people still think of the Edwards as a giant underground savings account. It is not. It is more dynamic than that. It responds to rainfall patterns, watershed conditions, pumping, springflow obligations, and drought. San Antonio has understood this for years, which is why SAWS spent the last quarter century diversifying away from overdependence on the Edwards. SAWS says its broader water-supply strategy has reduced Edwards reliance to about 60 percent of total supply. That is a major shift, and it tells you something important: the region’s largest utility no longer behaves as though the Edwards alone can safely carry the future. [6]
Canyon Lake and Medina Lake Are Not the Same Story
People often talk about Canyon Lake and Medina Lake as though they are simply two lakes in the same drought. That is too simplistic.
Canyon Lake is the region’s principal surface-water anchor. It was built by the U.S. Army Corps of Engineers for flood control and water conservation, and today it plays a central role in regional municipal supply. GBRA’s Western Canyon Water Treatment Plant, which began delivering treated water in 2006, uses Canyon Lake water to serve communities and utilities including Boerne, Fair Oaks Ranch, and SAWS. In plain English, Canyon Lake is not just a recreational asset. It is a key part of the municipal supply chain. When Canyon Lake is low, that matters far beyond the shoreline. [2][9]
Medina Lake is a different kind of asset with a different history. Medina Reservoir was constructed from 1911 to 1912 as an irrigation reservoir, and the Bexar-Medina-Atascosa system still ties it to roughly 33,000 acres of irrigated farmland. That alone makes it important. But Medina Lake also matters for another reason that gets far less attention: seepage losses from Medina and Diversion Lakes can recharge the Edwards Aquifer and the upper zone of the Trinity Aquifer. In other words, Medina has been more than a lake. Under the right conditions, it has been part of the region’s groundwater machinery. [10][11][12]
There is an important nuance here. USGS has shown that the amount of recharge associated with Medina Lake depends heavily on lake stage and which geologic units are in contact with the water. Around 1,045 feet above mean sea level, Medina Lake is in hydrologic connection with more permeable rocks in the Edwards recharge zone. At today’s level, it is nowhere near that. On March 17, 2026, Medina Lake stood at 977.51 feet, which is about 86.69 feet below conservation pool. That means Medina is not just visually low. It is operating in a state where both its storage value and its recharge contribution are far more limited than most people realize. [3][11][12]
How Boerne and Fair Oaks Ranch Actually Get Their Water
Boerne is not dependent on one source, and that is a good thing. According to the city’s 2023 annual water report, Boerne’s water came from three main sources: approximately 59 percent from the Western Canyon Regional Water Supply Project, 19 percent from Boerne Lake, and 22 percent from groundwater wells. The city also uses reclaimed water for irrigation, which helps reduce pressure on the potable system during peak demand periods. That is a smart setup. But it is not a magic shield. Boerne’s system still depends on a healthy regional surface-water and groundwater balance, plus enough infrastructure and storage to manage seasonal spikes. [7]
Fair Oaks Ranch also relies on a blended model. The city says it operates groundwater pumps from the Trinity Aquifer, four water treatment plants, and a distribution system, while also purchasing treated water from GBRA and mixing it with treated groundwater. Again, that is a resilience strategy, not a guarantee of abundance. A diversified suburban system is better than a single-source system, but it still lives inside the same drought-prone, growth-stressed regional water economy as everyone else. [8]
What the Last 25 Years Did to the Math
The region’s water challenge did not appear out of nowhere. The denominator changed.
Since 2000, Bexar County has grown from 1,392,931 to 2,127,737. Comal County has grown from 78,021 to 201,628. Kendall County has grown from 23,743 to 51,828. Medina County has grown from 39,304 to 55,619. At the city level, San Antonio has grown from 1,144,646 to 1,526,656. Boerne has gone from 6,178 to 22,712. Fair Oaks Ranch has gone from 4,695 to 11,744. Those are not marginal changes. They are structural changes. Boerne more than tripled. Fair Oaks Ranch roughly doubled and a half. Comal County more than doubled. Kendall County more than doubled. That kind of growth changes everything about water demand, infrastructure timing, seasonal peaks, and the cost of reliability. [13][14][15][16][17][18][19][20]
A second point matters just as much: this growth has not been evenly distributed. Much of it has pushed outward into the very counties and communities most tied to the Hill Country water system. That means the issue is not simply that “Texas is growing.” It is that the San Antonio–Hill Country corridor is adding population exactly where surface water, groundwater, aquifer recharge, and suburban development pressures most directly collide. [18][21]
The Next 25 Years Will Not Be Easier
Official projections point in one direction: more people, more demand, and more pressure on water infrastructure.
The Texas Demographic Center’s projections used in AAMPO planning show Bexar County reaching 3,102,720 by 2060, Comal County 584,380, Kendall County 111,448, and Medina County 61,719. That tells its own story. Bexar keeps getting larger. Comal continues to surge. Kendall keeps climbing. Medina grows more modestly but still grows. The adopted 2026 Region L Regional Water Plan points the same way, assuming continued regional growth and rising municipal demand over the coming decades. The broad takeaway is unavoidable: the last 25 years were not a temporary burst. They were part of a longer pattern. [21][22]
That is why the region’s water problem should not be framed as “Will we have water?” The better question is, “What kind of water system will be required to support the region we are becoming, and what will that system cost?” That is a much more serious question, because the cheapest, easiest, most local water has already been spoken for. [6][22]
The Real Supply Options Going Forward
There is no silver bullet. There is only a menu of harder, more expensive, and more infrastructure-heavy options.
Conservation and demand management
This is the least glamorous answer, but it is still the first answer. Better irrigation practices, leak reduction, reclaimed water, seasonal restrictions, and demand smoothing are not exciting, but they buy time and reduce strain on every other part of the system. They are not enough by themselves to absorb decades of growth, but any serious water strategy that does not start here is unserious. [6][7]
Expanded reuse
San Antonio has already been down this road and will almost certainly go further. Reuse works because the water is already in the urban system. Every gallon that can be reclaimed for irrigation, industrial use, cooling, or eventually more advanced treatment is a gallon that does not have to be pulled from a freshwater source. The challenge is cost, treatment complexity, public acceptance, and the fact that reuse infrastructure is not built overnight. Still, this is one of the most rational long-term strategies available. [6]
Aquifer storage and recovery
This is one of the smarter tools in the box because it addresses a Texas-specific weakness: evaporation. SAWS’ aquifer storage and recovery system stores excess water underground and recovers it when drought makes that water more valuable. SAWS says it recovered more than 50,000 acre-feet during the 2011–2014 drought, delivered close to 28,300 acre-feet in 2024, and plans for total storage volume of approximately 200,000 acre-feet. The advantage is obvious. Water stored underground does not evaporate the way water stored in a surface reservoir does. The limitation is equally obvious. Storage is not the same thing as a new source. You still need water available to store in the first place. [25]
Brackish groundwater desalination
For inland South-Central Texas, this is one of the most credible “new water” options. The Texas Water Development Board says the average cost of desalinated brackish groundwater runs roughly $357 to $782 per acre-foot, compared with about $800 to $1,400 per acre-foot for seawater desalination. SAWS already uses this approach through its Wilcox Aquifer desalination facility, which produces about 10 million gallons of drinking water per day. The appeal is straightforward: brackish desal is more drought-resistant than waiting on the next lake refill. The tradeoffs are energy, concentrate disposal, capital cost, and deep-well development. [23][24]
Importing water from elsewhere
This is not theoretical. San Antonio already imports water through Vista Ridge. SAWS says the project is a 142-mile pipeline and provides up to 50,000 acre-feet per year of Carrizo and Simsboro groundwater from Burleson County. So when people say, “Why don’t we just pipe water in from somewhere else?” the answer is: we already do. The real issue is cost, long-term supply rights, regional politics, and how much more of that model can be scaled before the economics get ugly. [26]
Large regional projects such as WaterSECURE
This is where water planning starts to look like major-state infrastructure planning. Public documents presented to New Braunfels Utilities describe WaterSECURE as a project involving two off-channel reservoirs, a 140 MGD treatment plant, 160 miles of local pipelines, and a total capital cost of about $5.8 billion, with estimated water cost near $4,800 per acre-foot. That is the right scale for the problem, but it also tells you something sobering: future reliability will not come cheap. It will come with large capital commitments, long permitting timelines, complicated regional coordination, and a willingness to pay for resilience before the crisis arrives. [28]
Coastal desalination
Coastal seawater desalination is often presented as the obvious long-term answer. It is certainly one possible answer, but it is not a cheap or simple one. The TWDB’s cost range already puts seawater desalination above brackish groundwater desalination before you add the cost of moving that water far inland. On top of that, Corpus Christi’s Inner Harbor desalination proposal came in at a preliminary guaranteed maximum price of $978.77 million in February 2026. And that is the plant itself, not a pipeline all the way to San Antonio or the Hill Country. Technically possible, yes. Financially painless, no. [23][27]
What This Means for San Antonio, Boerne, Fair Oaks Ranch, Canyon Lake, Medina Lake, and the Edwards
The honest conclusion is not that the sky is falling. It is that the easy era is over.
The San Antonio–Hill Country region can keep growing, but not on the old assumption that one aquifer and a couple of lakes will somehow absorb decades of new demand without major consequences. The Edwards will remain indispensable, but it cannot be treated as an unlimited reserve. Canyon Lake will remain strategic, but it is still drought-sensitive. Medina Lake will remain historically and hydrologically important, but at very low levels it is a weakened storage asset and a diminished recharge contributor. Boerne and Fair Oaks Ranch are in better shape than communities tied to a single fragile source, but they are still operating inside a larger regional system that is becoming more expensive and more complex to sustain. [1][2][3][6][7][8][11][12]
In the end, this is not just a water story. It is a regional maturity story. A place reaches a certain size and eventually has to decide whether it will keep acting as though yesterday’s infrastructure can carry tomorrow’s growth. In South-Central Texas, that question now runs straight through the aquifer, the lakes, the pipes, the treatment plants, the growth projections, and the price of every future gallon. [21][22][23][28]
FAQ
Are San Antonio, Boerne, and Fair Oaks Ranch running out of water?
Not in the simplistic sense that taps are about to stop flowing. The real issue is that dependable future supply is becoming more expensive, more diversified, and more infrastructure-intensive to secure. That is a long-term constraint, not a Hollywood-style sudden failure. [6][7][8]
Why does the Edwards Aquifer matter so much?
Because it is still the backbone of the region’s water system. It is productive, but it is not static. Most recharge comes through streams crossing the recharge zone, which means rainfall patterns, watershed health, and stream losses matter enormously. [4][5]
Why are Canyon Lake and Medina Lake not interchangeable?
Because they serve different roles. Canyon Lake is a major regional municipal supply reservoir tied directly to treatment and delivery through GBRA. Medina Lake has a strong irrigation history and also contributes, under the right conditions, to groundwater recharge. When each lake is low, the operational consequences are different. [9][10][11][12]
Why is Medina Lake’s low level more important than it looks?
Because at very low stages, Medina is not just storing less water. It is also contributing less recharge to the underlying groundwater system than it can at higher levels. That makes a very low Medina Lake a double problem. [3][11][12]
How does Boerne get its water?
Boerne uses a mix of Canyon Lake water through GBRA, Boerne Lake water, and groundwater wells. Its reclaimed-water system also helps reduce potable demand. [7]
How does Fair Oaks Ranch get its water?
Fair Oaks Ranch uses groundwater from the Trinity Aquifer and treated water purchased from GBRA, blending those sources through its own treatment and distribution system. [8]
What changed over the last 25 years?
Population growth changed the denominator. San Antonio, Boerne, Fair Oaks Ranch, Bexar County, Comal County, Kendall County, and Medina County all grew materially, and some of them grew dramatically. More people means more year-round demand, bigger summer peaks, and more pressure on storage and treatment systems. [13][14][15][16][17][18][19][20]
What do the next 25 years look like?
More growth, not less. Official projections used in regional planning show substantial additional growth across Bexar, Comal, Kendall, and Medina counties through 2060. [21][22]
What is the most realistic new water source for this region?
There is no single answer, but brackish groundwater desalination, reuse, aquifer storage and recovery, and selective imported supplies look more realistic in the near-to-mid term than relying on one giant miracle project. [23][24][25][26]
Is coastal desalination the answer?
It may become part of the answer, but it is not a cheap shortcut. It costs more per acre-foot than brackish groundwater desalination, and inland delivery would add significant transmission cost on top of the plant itself. [23][27]
What is the single biggest takeaway?
The region’s future will depend less on one rainy season or one new project than on whether local communities accept that future reliability will come from a diversified, carefully managed, and increasingly expensive water portfolio. [6][21][22][23][28]
Citations
- Edwards Aquifer Authority current conditions:
https://www.edwardsaquifer.org/ - Canyon Lake reservoir data:
https://waterdatafortexas.org/reservoirs/individual/canyon - Medina Lake reservoir data:
https://waterdatafortexas.org/reservoirs/individual/medina - Edwards Aquifer Authority, aquifer science:
https://www.edwardsaquifer.org/aquifer-science/about-the-edwards-aquifer/ - Texas State Soil and Water Conservation Board, Edwards Aquifer Recharge Zone:
https://www.tsswcb.texas.gov/sites/default/files/files/programs/agency-reports/Edwards%20Aquifer%20Recharge%20Zone.pdf - San Antonio Water System, water supplies and diversification:
https://www.saws.org/your-water/management-sources/ - City of Boerne 2023 Annual Drinking Water Quality Report:
https://www.ci.boerne.tx.us/DocumentCenter/View/23929/2023-Annual-Drinking-Water-Quality-Report?bidId= - Fair Oaks Ranch, City’s Water Sources:
https://www.fairoaksranchtx.org/222/Citys-Water-Sources - Guadalupe-Blanco River Authority, Western Canyon Water Treatment Plant:
https://www.gbra.org/operations/water-treatmentold/ - Bexar-Medina-Atascosa Water Control and Improvement District, Medina Lake history:
https://bmawater.org/about-us/history/ - U.S. Geological Survey, Hydrogeology, Hydrologic Budget, and Water Chemistry of the Medina Lake Area, Texas:
https://www.usgs.gov/publications/hydrogeology-hydrologic-budget-and-water-chemistry-medina-lake-area-texas - U.S. Geological Survey, Water-budget analysis of the Medina and Diversion Lake system and estimated recharge to the Edwards and Trinity aquifers:
https://pubs.usgs.gov/publication/sir20245112/full - Texas State Library and Archives Commission, 2000 Census county populations:
https://www.tsl.texas.gov/ref/abouttx/popcnty12000.html - Texas State Library and Archives Commission, 2000 Census city populations:
https://www.tsl.texas.gov/ref/abouttx/popcity2000.html - U.S. Census Bureau QuickFacts, Bexar County, Texas:
https://www.census.gov/quickfacts/fact/table/bexarcountytexas/PST045224 - U.S. Census Bureau QuickFacts, Boerne city, Texas:
https://www.census.gov/quickfacts/fact/table/boernecitytexas/PST045224 - U.S. Census Bureau QuickFacts, Fair Oaks Ranch city, Texas:
https://www.census.gov/quickfacts/fact/table/fairoaksranchcitytexas/PST045224 - U.S. Census Bureau QuickFacts, Comal County, Texas:
https://www.census.gov/quickfacts/fact/table/comalcountytexas/PST045224 - U.S. Census Bureau QuickFacts, Kendall County, Texas:
https://www.census.gov/quickfacts/fact/table/kendallcountytexas/PST045224 - U.S. Census Bureau QuickFacts, Medina County, Texas:
https://www.census.gov/quickfacts/fact/table/medinacountytexas/NES010222 - Texas Demographic Center / AAMPO presentation, projected population growth:
https://demographics.texas.gov/Resources/TDC/Presentations/2c8ab433-d69e-4a8c-9f3e-cc82dc1b90a6/20241004_AAMPO.pdf - 2026 South Central Texas (Region L) Regional Water Plan:
https://www.regionltexas.org/wp-content/uploads/2025/10/2026-Regional-Water-Plan_L_2026_condensed.pdf - Texas Water Development Board, desalination facts and cost ranges:
https://www.twdb.texas.gov/innovativewater/desal/facts.asp - San Antonio Water System, brackish groundwater desalination:
https://www.saws.org/your-water/management-sources/brackish-groundwater-desalination/ - San Antonio Water System, aquifer storage and recovery:
https://www.saws.org/your-water/management-sources/aquifer-storage-recovery/ - San Antonio Water System, Vista Ridge Pipeline project:
https://www.saws.org/your-water/management-sources/vista-ridge-pipeline2/about-this-project/ - City of Corpus Christi, Inner Harbor desalination project cost proposal:
https://www.corpuschristitx.gov/news/posts/city-of-corpus-christi-receives-cost-proposal-for-inner-harbor-desalination-project/ - New Braunfels Utilities / GBRA WaterSECURE project presentation:
https://mccmeetingspublic.blob.core.usgovcloudapi.net/nbutx-meet-92edcb2bc85c48918cbf80842e562d30/ITEM-Attachment-001-af25345a239a4378ba43f97e8de611f8.pdf
