San Antonio & Drought: 25 Years of Crisis, Conservation, and Complicated Rainfall

Edwards Aquifer · Drought Monitor · Municipal Demand · April 2026 Flood Event

Olivia Shipley

April 2026

In December, nearly all of Bexar County was classified as extreme drought. By late April, the same region was under flash flood warnings. This analysis draws on five data sources to trace where San Antonio’s water supply has been over the past 25 years & what this week’s flood event looked like on the gauges.

Figure 1

The J-17 index well, located near downtown San Antonio, is the primary metric used by the Edwards Aquifer Authority (EAA) to regulate pumping across the region. The annual average elevation recorded at this well declined from approximately 685 feet in the late 1970s to 625 feet by 2026, a reduction of roughly 60 feet over five decades. When the well falls below 660 feet, Stage 1 restrictions take effect; below 640 feet, the region enters Stage 3, which carries significant mandatory reductions for agricultural, municipal, and industrial permit holders alike. As of the 2026 average, the aquifer sits within the Stage 3–4 restriction zone.

Figure 2

This chart displays the proportion of Bexar County classified under each U.S. Drought Monitor severity category on a weekly basis from 2000 through 2025. The height of the colored area at any point in time reflects the total share of the county in some form of drought that week. Two periods of dense, dark-red coverage are visible: one centered on 2011, and a second sustained period beginning around 2022 and extending through the end of 2025. December 2025 ended with 94% of the county classified as D3 Extreme Drought, with no weeks free from at least moderate drought conditions for the preceding three years.

Figure 3

Aggregating the weekly drought data to the annual level reveals the distribution of severe drought exposure across the 25-year record. The year 2006 recorded the highest single-year D3+ coverage at 98%, meaning nearly every week that year the entire county was classified at extreme or exceptional drought severity. The years 2008, 2009, 2010, and 2011 also recorded values above 70%. A second cluster of high-exposure years is visible from 2022 through 2025, with 2025 ending at 84%. This chart does not show the duration or continuity of drought within a year — for that, Figure 2 provides the week-by-week breakdown.

Figure 4

Municipal water demand in Bexar County rose steadily from the mid-1970s through approximately 2000, reaching a recorded high of around 330,000 acre-feet. Since that peak, total annual demand has declined and stabilized at roughly 200,000–230,000 acre-feet, a level comparable to what was recorded in the early 1980s. The J-17 aquifer elevation (red line, right axis) tracks inversely against cumulative drought stress rather than against annual demand alone, reflecting the multi-year nature of aquifer recharge and depletion cycles. Note that the TWDB data used here records total municipal withdrawals and does not include population figures; per-capita trends cannot be calculated from this dataset alone.

Figure 5

On April 20–21, 2026, three USGS-monitored stream channels in the San Antonio metro area recorded gage heights above their respective flood stage thresholds. Salado Creek at Loop 13 reached a peak of 19.27 feet on April 21, exceeding its major flood stage threshold of 18 feet. Leon Creek at Loop 410 peaked at 11.34 feet (flood stage: 10 feet), and Leon Creek at IH-35 peaked at 11.70 feet (flood stage: 9 feet). All three gauges recorded a return to below flood stage within approximately 24 hours of their respective peaks. Data from this chart are provisional and subject to revision by the USGS.

Regional Water Management: SAWS, SARA, and the Edwards Aquifer Authority

The five charts above document a water system operating under sustained stress — decades of aquifer drawdown, repeated and severe drought cycles, and the acute pressure of urban flooding events within the same calendar year. Managing these conditions falls primarily to three agencies whose programs shape the region’s water future.

San Antonio Water System (SAWS) is the municipal utility serving the city and surrounding areas, and it has developed one of the most comprehensive urban water conservation portfolios in the country. The WaterSaver program provides direct rebates to residential and commercial customers who install water-efficient fixtures, upgrade irrigation systems, or convert lawns to drought-tolerant native landscapes — reducing outdoor water demand, which accounts for a significant share of summer peak use. SAWS’s tiered rate structure prices water progressively, with higher per-gallon costs at greater usage volumes, creating a financial incentive for conservation across all customer classes. The Aquifer Storage and Recovery (ASR) program is one of the largest municipal ASR systems in the United States: during periods of above-normal aquifer levels or wet weather, SAWS pumps water into the subsurface limestone and stores it for recovery during drought periods. This effectively uses the Edwards Aquifer itself as a reservoir, reducing dependence on surface storage. SAWS also operates a recycled water distribution system that provides treated, non-potable water for industrial cooling, power generation, and large-scale irrigation — directly offsetting demand on the Edwards Aquifer.

San Antonio River Authority (SARA) manages the San Antonio River basin with a dual mandate of water quality and flood control. The basin includes the San Antonio River and its major tributaries — among them Salado Creek and Leon Creek, both of which exceeded flood stage during the April 2026 event documented in Figure 5. SARA operates a network of stream gauges, flood early warning systems, and automated notification infrastructure that supports emergency response across the county. Its capital improvement programs have constructed and maintained flood control reservoirs, channel modifications, and detention facilities throughout the watershed. The Salado Creek Greenway project — a multi-decade effort running through north and central San Antonio — combines flood attenuation infrastructure with public trail corridors, providing both hydraulic capacity and community greenspace. SARA’s programs are funded through a combination of county drainage district fees, state grants, and federal cost-share arrangements, reflecting the regional scope of flood risk management.

The Edwards Aquifer Authority (EAA) is the regulatory agency responsible for managing groundwater withdrawals from the Edwards Aquifer under a permit system established by state law. The EAA’s critical period management protocol — triggered by J-17 readings — is the mechanism that translates aquifer elevation data into enforceable pumping restrictions. At Stage 1 (J-17 below 660 feet), permit holders face a 20% reduction in pumping rights; at Stage 4 (below 625 feet), reductions reach 35% or more depending on permit type. The EAA also funds aquifer science, recharge enhancement projects, and environmental flow programs designed to maintain spring flows at Comal and San Marcos springs, which are federally protected habitat for several endangered species.

Together, these three agencies represent a layered approach to water security in a region where the margin between sufficiency and shortage is measured in feet of aquifer elevation and inches of annual rainfall.

Data sources: Edwards Aquifer Authority (J-17 Index Well) · Texas Water Development Board (Historical Water Use Survey) · U.S. Drought Monitor / National Drought Mitigation Center · USGS National Water Information System. Analysis by Olivia Shipley.