Serving the Texas Hill Country & San Antonio since 1989
Two homes ten miles apart in the Hill Country can have completely different water. One is on a city supply blended from a lake and an aquifer; the other is on a private well into a different rock layer. This guide explains where the water comes from in each county we serve, and what that usually means for treatment.
The short answer
Water in San Antonio and the Texas Hill Country comes from a mix of limestone aquifers (mainly the Edwards and the Trinity, plus the Ellenburger and Hickory around Fredericksburg) and surface water (Canyon Lake, the Guadalupe River and local lakes). Groundwater here is very hard almost everywhere. Private wells, mostly in the Trinity, often add iron, sulfur and higher dissolved solids. City supplies that blend lake and well water can change with the seasons.
County by county
San Antonio · Helotes · Stone Oak · northern Bexar
Edwards AquiferTrinity wells north of the cityWhat it usually needs: a correctly sized softener, carbon filtration for disinfectant taste, and reverse osmosis at the kitchen tap if you want better drinking water. San Antonio water treatment →
New Braunfels · Canyon Lake · Bulverde · Spring Branch
Canyon LakeGuadalupe RiverEdwardsTrinityWhat it usually needs: softening on both city and well water; on wells, iron and sulfur treatment first. Because the city blend shifts with river flow and lake levels, retesting yearly is worthwhile. New Braunfels · Canyon Lake · Bulverde · Spring Branch
Boerne · Comfort · rural Kendall
Canyon Lake (GBRA)Boerne City LakeTrinityWhat it usually needs: softening plus carbon filtration for taste and odor on city water; a full well train on rural properties. Boerne · Comfort
Kerrville · Ingram · Hunt · Center Point
Guadalupe RiverLower TrinityEllenburgerWhat it usually needs: a softener sized for the hardest source in the mix; on wells, iron, sulfur and sediment treatment first. Kerrville water treatment →
Fredericksburg · Stonewall · rural Gillespie
EllenburgerHickoryWhat it usually needs: softening, plus lab testing and targeted treatment on private wells. Fredericksburg water treatment →
Bandera · Pipe Creek · Lakehills
TrinityWhat it usually needs: a complete well treatment train with softening sized to a well-level reading. Bandera water treatment →
Blanco · Johnson City · rural Blanco
Hill Country TrinityWhat it usually needs: well pre-treatment, then softening. Blanco water treatment →
San Marcos · Wimberley · Dripping Springs · Seguin · Marble Falls
In northern Hays County, residents rely mainly on the Middle Trinity Aquifer, so the well guidance above applies around Wimberley and Dripping Springs. City customers in San Marcos, Seguin and Marble Falls are on utility supplies, which we test on site like any other. San Marcos · Wimberley · Dripping Springs · Seguin · Marble Falls
At a glance
| Source | Where it is used | What it usually brings |
|---|---|---|
| Edwards Aquifer | San Antonio (SAWS), New Braunfels | Very hard water from limestone |
| Trinity Aquifer | Most private wells from Bandera to Blanco; some Boerne, Kerrville and New Braunfels wells | Very hard, more mineralized than the Edwards; sulfate, chloride, iron and sulfur are common |
| Ellenburger and Hickory aquifers | Fredericksburg and rural Gillespie; one Kerrville well | Hard groundwater; Hickory wells can carry natural radioactivity |
| Canyon Lake (via GBRA or NBU) | Boerne, New Braunfels and other GBRA customers | Treated surface water; seasonal taste and odor shifts possible |
| Guadalupe River | Kerrville, New Braunfels | Treated surface water, blended with groundwater |
Whichever source you are on, the number that matters is the one from your own tap. That is what our free test measures.
Overview
Our service area runs from San Antonio and Bexar County north and west through the Texas Hill Country: Comal, Kendall, Kerr, Gillespie, Bandera and Blanco counties, plus nearby parts of Hays, Guadalupe and Burnet counties.
Across that service area, water comes from very different places: the Edwards Aquifer under San Antonio, the Trinity under much of the Hill Country, the Ellenburger and Hickory around Fredericksburg, Canyon Lake and the Guadalupe River. That is why two homes in the same service area can need completely different treatment.
Every visit anywhere in our service area starts the same way: a free on-site water test, the results in writing, and a recommendation built on your numbers. City water and private wells are both covered.
Not sure whether you are inside our service area? Call (210) 635-7418 and we will tell you, and book your free test while we are on the phone.
Common questions
San Antonio and the Texas Hill Country across Bexar, Comal, Kendall, Kerr, Gillespie, Bandera and Blanco counties, and out to San Marcos, Wimberley, Dripping Springs, Seguin and Marble Falls. Testing is free anywhere in that area.
Boerne Utilities uses three sources: Canyon Lake water delivered through the Guadalupe-Blanco River Authority’s Western Canyon project, Boerne City Lake, and groundwater wells. Canyon Lake water now makes up the largest share.
The City of Kerrville reports about 80 percent from the Guadalupe River and about 20 percent from the Lower Trinity Aquifer, and it stores treated river water underground through aquifer storage and recovery wells.
Fredericksburg uses groundwater only. Its 2024 water quality report lists eight wells in the Ellenburger Aquifer and one in the Hickory Aquifer.
Often, yes. Private wells, mostly in the Trinity Aquifer, frequently test harder than nearby city supplies and usually carry other minerals such as iron and sulfur. Wells also vary from property to property, so a test is the only reliable way to know.
On-site water testing and the written quote are free anywhere in our service area, with no obligation.
Gaines Soft Water is a family-owned water treatment company serving San Antonio and the Texas Hill Country since 1989, across Bexar, Comal, Kendall, Kerr, Gillespie, Bandera and Blanco counties and parts of Hays, Guadalupe and Burnet counties.
San Antonio’s city water comes mainly from the Edwards Aquifer. New Braunfels Utilities blends Canyon Lake, Edwards, Trinity and Guadalupe River water. Boerne combines Canyon Lake water from GBRA, Boerne City Lake and wells. Kerrville relies mostly on the Guadalupe River with Lower Trinity wells and aquifer storage. Fredericksburg uses Ellenburger and Hickory aquifer wells. Rural properties across the region mostly use Trinity Aquifer wells, which tend to be more mineralized than Edwards water.
Groundwater in the region is very hard almost everywhere. Gaines tests water on site for free and designs softening, filtration, reverse osmosis and well treatment around the result. Phone: (210) 635-7418.
Free on-site testing anywhere from San Antonio to Fredericksburg, with your numbers and a firm written price.
