Buyers looking at acreage around Austin usually think hard about the house and barely at all about where the water comes from. Outside the reach of a municipal supply, that question determines whether a property is livable, and the answers are testable before you commit.
The three sources
A private well. The most common on Hill Country acreage. You own it, you maintain it, and its productivity is a property of the geology beneath you rather than anything you can change.
A shared or community system. A small utility serving a subdivision. You pay a bill and somebody else maintains it. Ask who, what it costs, and what condition the system is in, because a small system with deferred maintenance can produce assessments in the same way a condo association does.
Rainwater collection. Roof catchment into storage tanks, sometimes as the primary supply and often alongside a well. Well established in this region and entirely practical with adequate storage and treatment.
Many properties combine two of these, which is generally a good sign rather than a bad one.
Testing a well: two different tests
Buyers frequently run one and assume they have covered it. They are separate questions.
Quality. A laboratory analysis of what is in the water: bacteria, nitrates, and the mineral content that determines whether you will want treatment. Most issues here are treatable, and the point is knowing what treatment the property needs and what it costs to run.
Quantity. A flow test that draws the well down over a sustained period and measures what it delivers. This is the one that decides whether a household can actually live there, and it is the one more often skipped.
A well can test clean and still be inadequate. Ask for a sustained draw rather than a spot reading, and be sceptical of a test conducted in a wet season on a well that has not been used for months.
The questions that reveal the real picture
- How deep is it, and when was it drilled? Drillers file reports, and the log tells you what the well encountered.
- Has it ever gone dry or been deepened? A well that was deepened once has a history worth understanding.
- What is the pump, and how old? Pumps have finite lives and replacement on a deep well is not a small expense.
- Is there storage? A modest producing well with a large storage tank can comfortably serve a household that the raw flow rate suggests it could not.
- What treatment is in place? Softening, filtration, and disinfection all have running costs.
- What did the neighbours experience in the last drought? The most useful question on this list, and the one nobody asks.
Groundwater is regulated locally
Texas groundwater is generally tied to surface ownership, subject to regulation by groundwater conservation districts. Those districts set rules on permitting, well spacing, and in some cases production, and they differ from one another.
Find out which district covers the property and what its rules are, particularly if you intend to drill a new well or increase production. Rules have tightened in parts of this region as demand has grown, and what a neighbour was permitted a decade ago is not necessarily what you will be permitted now.
Much of the ground west and southwest of Austin sits over the Edwards Aquifer recharge zone, which carries additional environmental requirements affecting development generally. That intersects with the septic question on the same properties. See septic vs city sewer outside Austin.
Rainwater, practically
Collection systems here are usually roof catchment into large tanks, with filtration and disinfection for potable use. The design question is storage capacity relative to roof area and rainfall, and the reason capacity matters is that Central Texas rainfall is not evenly distributed. It arrives in bursts with long dry stretches between, so the system has to carry you through the gaps rather than through an average.
Properties designed around collection from the start tend to do it well. Systems added later are worth evaluating on capacity rather than on the fact of existing.
Where this applies
Commonly around Dripping Springs, Spicewood, Wimberley, Liberty Hill, and the more rural parts around Lago Vista. These are places people move to precisely for the land, and water is the thing that makes the land work.
What we do about it
We test quality and quantity separately, pull the driller's log where one exists, find out which groundwater district applies, and ask the neighbours what happened in the last dry year. On raw land we want the water question answered before you buy, not after you have a house design.