Land guide · Water

Well or rainwater? How to choose for Central Texas land

Raw land out here usually doesn't come with water. Most folks in Hays, Travis, Comal, Blanco, Caldwell and Bastrop counties end up drilling a well, catching rain off the roof, or both. Some can hook up to a water utility, and some have water hauled in. Here's how to pick, with the numbers and where they come from.

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The free snapshot gives a quick read on water for your exact spot. The full report ($29) adds a map of nearby wells, the groundwater district's rules, the closest water utilities and rainfall.

First: is there a water line close by?

If a city or a water supply corporation already serves the land, or its line runs along the road, call them before you price a well or tanks. The Texas Water Development Board says a rainwater system usually costs more up front than getting water from a utility, and about the same as drilling a new well (TWDB Rainwater FAQ). So a hookup may be the cheapest choice. You can look up service areas on the Public Utility Commission water utility map; being near one doesn't promise service. Hookup fees and line extensions vary a lot from one provider to the next: varies, ask the utility for a written quote.

Hauled water is the other option: a truck fills a storage tank. People use it to get started, as a backup when tanks run low, or where nothing else works. The TWDB rainwater manual suggests putting tanks where a water truck can reach them (TWDB manual). Price per load: varies, ask local haulers.

Quick check: which way do you lean?

Answer these five questions. Each answer says which way it leans.

1. Does a city or water supply corporation line already serve the land or run along the road? Yes (call the utility first) No (go on) Not sure (ask the utility, or check the PUC map)

2. Do neighbors' wells hold up in dry summers, and will the groundwater district accept a new household well there now? Yes (leans well) No (leans rainwater) Not sure (ask the district and the neighbors)

3. Will you have a big metal roof (house, barn or shed) to catch rain? Yes (leans rainwater) No (leans well)

4. Will you use a lot of water beyond the house, like livestock, a big garden or irrigation? Yes (leans well) No (leans rainwater)

5. Are you planning an FHA or other government-backed home loan? Yes (leans well; ask your lender about rainwater) No or not sure (ask your lender either way)

Pick your answers above and your leaning shows here.

Well vs. rainwater, side by side

	Drilled well	Rainwater collection
Upfront cost	About $12,000–$32,000 for a complete 400-foot well, or $15,000–$40,000 at 500 feet (HomeGuide, national, 2025). Hard Hill Country rock: varies, ask drillers.	About $15,000–$30,000 for a home system with 5,000–16,000 gallons of tanks, up to $45,000–$55,000 for 40,000+ gallons (one Hill Country installer, 2026).
Where the water comes from	The aquifer under your land.	Your roof, when it rains.
Biggest risk	A weak or dry well, or one that fails in drought.	Running dry in a long dry spell. TWDB says rainwater "cannot be relied on as a long-term, drought-proof source."
Permits	Most districts here want a new well registered before drilling (see below).	No state plumbing standards if it's not tied to a public water line (TWDB). Ask the county.
Drinking-water treatment	Depends on a lab test. Test at least yearly (Texas Well Owner Network).	Filters plus an ultraviolet light is the most common Texas setup (TWDB manual).
The water itself	Can be hard (high in minerals) in some aquifers (TWDB manual).	Soft and slightly acidic, with no salts or minerals (TWDB).
Upkeep	A well pump lasts about 8–15 years (HomeGuide).	Clean gutters and the roof washer, change filters, replace the UV bulb (TWDB manual).
Space	A small spot, kept away from septic and property lines.	A big level pad: 15–24 feet across for 5,000–16,000 gallons (installer).
Home loans	Common; a lender can ask for a water test (HUD).	FHA's older guidance didn't accept cistern-only homes except by waiver (HUD). Ask your lender.

If you drill a well

How deep, by county

Depth drives the price, because drillers charge by the foot. From our count of Texas Water Development Board well records:

County	Typical depth	Middle half
Hays	about 500 ft	400–700 ft
Travis	about 420 ft	260–620 ft
Comal	about 480 ft	380–600 ft
Blanco	about 350 ft	210–460 ft
Caldwell	about 240 ft	160–350 ft
Bastrop	about 320 ft	210–460 ft

Drilled depth, not water depth. Rounded to 10 feet. More in How deep are wells? (by county) and on the well depth map.

What it costs

HomeGuide's national cost guide (July 2025) puts a complete well (drilling, casing, pump, wiring and permits) at $30 to $80+ per foot. Its depth table shows about $12,000–$32,000 at 400 feet and $15,000–$40,000 at 500 feet. It lists a pump at $400–$2,500, a pressure tank at $800–$1,500 and a lab water test at $100–$350 (HomeGuide). These are national numbers, so Hill Country prices: varies, ask at least three licensed local drillers for written quotes that list the per-foot price, casing, pump and any trip charges.

There's no promise of water. The TWDB manual warns that drilling comes "with no guarantee of hitting a reliable source of water," and the deeper you go, the more it costs (TWDB manual).

Permits: the groundwater district comes first

Texas law exempts a household or livestock well on more than 10 acres that can't pump more than 25,000 gallons a day from a pumping permit, but the well still has to be registered with the district (Texas Water Code §36.117). Each district has its own forms and spacing rules:

County	District and its first rule for a new household well
Hays	Hays Trinity Groundwater Conservation District (HTGCD): A household well for one home that can't pump more than 25,000 gallons a day (about 17 gallons a minute) is exempt from a pumping permit, but it must be registered. Barton Springs/Edwards Aquifer Conservation District (BSEACD): Every well has to be registered with the district. Plum Creek Conservation District (PCCD): Plum Creek CD regulates groundwater in parts of Hays and Caldwell counties. Edwards Aquifer Authority (EAA): The EAA covers wells that pull from the Edwards Aquifer. In much of the Hill Country, household wells are drilled into the deeper Trinity Aquifer instead, which another district oversees. The EAA will tell you whether a well is an Edwards well.
Travis	Southwestern Travis County Groundwater Conservation District (SWTCGCD): Before a new well is drilled, you register it and get a Well Drilling Authorization from the district (Rule 3.3). The authorization is good for six months. Barton Springs/Edwards Aquifer Conservation District (BSEACD): Every well has to be registered with the district.
Comal	Comal Trinity Groundwater Conservation District (CTGCD): Every new well, including a household or livestock well, needs a written Drilling Authorization from the district before drilling starts. It doubles as the well registration and expires if the well isn't drilled within a year (Rules 5.2-5.4). Edwards Aquifer Authority (EAA): The EAA covers wells that pull from the Edwards Aquifer. In much of the Hill Country, household wells are drilled into the deeper Trinity Aquifer instead, which another district oversees. The EAA will tell you whether a well is an Edwards well.
Blanco	Blanco-Pedernales Groundwater Conservation District (BPGCD): You need written authorization from the district before a new well is drilled. Register the well first; the registration is the application, and drilling can start once the district issues the drilling authorization (Rule 3.3).
Caldwell	Plum Creek Conservation District (PCCD): Plum Creek CD regulates groundwater in parts of Hays and Caldwell counties. Gonzales County Underground Water Conservation District (GCUWCD): Every new well has to be registered with the district, and the State of Texas Well Report goes to the district office (Rule 4.A). Edwards Aquifer Authority (EAA): The EAA covers wells that pull from the Edwards Aquifer. In much of the Hill Country, household wells are drilled into the deeper Trinity Aquifer instead, which another district oversees. The EAA will tell you whether a well is an Edwards well.
Bastrop	Lost Pines Groundwater Conservation District (LPGCD): No new well may be drilled until it's registered with the district (Rule 4.1). A new exempt well's registration expires if the well isn't drilled and logged within 365 days (Rule 4.4).

Which district applies depends on the exact spot (and sometimes the aquifer). The full report names it and lists its rules. District list: TWDB.

Drought and wells failing in western Hays County

As of October 15, 2026, the Hays Trinity Groundwater Conservation District says it is in Emergency Drought Stage and won't accept new permits for production or non-exempt wells until conditions improve. Household (exempt) wells still need the district's forms before drilling. When we checked again on October 25, 2026, its home page also said: "Water wells are failing at an unprecedented rate." Source: the district's website.

Testing and upkeep

The Texas Well Owner Network says to test well water at least once a year for nitrate, total dissolved solids, and E. coli or fecal coliform bacteria (TWON).
TWDB says lab tests run from about $20 for a bacteria test to $400 for a full drinking-water panel, and some districts test for free or less (TWDB).
Budget for a new pump someday: HomeGuide says pumps last about 8 to 15 years.

If you collect rainwater

How much a roof catches

One inch of rain on one square foot of roof is 144 cubic inches of water, and a gallon is 231 cubic inches, so that's about 0.62 gallons per square foot per inch of rain. Gutters, splash and the first dirty flush lose some, so most installers count on catching 75–85% (TWDB Rainwater FAQ).

Example (TWDB's figures, Austin's 32 inches of rain a year):

A 2,000 sq ft roof: 2,000 × 0.62 × 85% × 32 in ≈ 33,700 gallons a year.
A water-saving household uses 25–50 gallons per person per day (TWDB manual). For 3 people at 50 gallons: 150 gallons a day, about 54,750 gallons a year.
Roof needed for that: 54,750 ÷ (0.62 × 85% × 32) ≈ 3,200 sq ft.
Tanks: one rule of thumb from the manual is to store three months of use with no rain, about 13,700 gallons here.

Rainfall changes across these six counties, and dry years come. The manual suggests using median (not average) rainfall and sizing for the longest stretch without rain, or planning a backup like a well or hauled water. The full report shows the average rainfall at your spot.

What it costs

One Hill Country installer publishes whole-system prices (tank, first-flush diverter, pump, filters and UV): $15,000–$30,000 for 5,000–16,000 gallons, $25,000–$35,000 for 20,000+, $35,000–$50,000 for 30,000+, and $45,000–$55,000 for 40,000+ gallons (Dripping Rainwater, checked October 2026).
TWDB's FAQ says a complete system for a typical home "will generally cost between $8,000 and $10,000," with tanks from about $0.50 a gallon (fiberglass) to more than $4 (welded steel). That page isn't dated and prices have gone up, so treat it as a floor (TWDB FAQ).
The tank is the biggest cost. Underground tanks cost more than tanks above ground (TWDB).

Making it safe to drink

The most common Texas setup is a 5-micron filter, then a 3-micron activated charcoal filter, then an ultraviolet (UV) light. Filters must be changed regularly, and UV bulbs replaced after at most 10,000 hours (TWDB manual).
For drinking water, the manual recommends a metal roof. It says asphalt or composite shingles "are not advisable."
Send the first dirty rinse off the roof away from the tank. One rule of thumb is at least 10 gallons for every 1,000 sq ft of roof.
The manual advises testing at least every three months if you drink it. There are no federal or state quality standards for rainwater, so check with the county health department about local testing rules (TWDB FAQ).

Texas rules that help

An HOA or POA can't ban rain barrels or a rainwater system. It can still keep them off common areas and out of the space between the front of the house and the street, require barrel colors that match the house, and set reasonable rules on size, type and screening when they're visible from the street. (Texas Property Code §202.007)
Rainwater collection equipment and supplies are exempt from Texas sales tax. (Texas Tax Code §151.355)
Drinking rainwater: if your home is NOT hooked to a public water system, the state's public-water rules don't apply. If a tank over 500 gallons has a backup from a public water line, you need a backflow device or air gap, must tell the water provider in writing, and potable hookups need a licensed plumber with a water-supply-protection endorsement. (Texas Health & Safety Code §341.042)
To skip the sales tax, give the seller Texas Comptroller form 01-339. Some local taxing units can also lower property taxes for water-saving systems, so ask your county appraisal district (TWDB FAQ).

Many folks do both

A well with rainwater tanks, or rainwater with a well or hauled water as backup, is common. The TWDB manual suggests putting tanks near the well house if you use a well as backup, so the plumbing is shared. Pairing them costs more up front but means one dry spell or one broken pump doesn't leave you without water.

Your water choice can change the lot size you need

Some counties set a bigger minimum lot for septic when the home is on its own well. In Comal County: In subdivisions created after January 1, 1988, a lot on septic needs at least 1 acre with public water, or at least 5.01 acres with its own well. Plats the county approved before its 2013 septic order are exempt. Hays County's minimums also depend on the water source. How rainwater counts for these rules: varies, ask the county.

Loans and insurance

Wells: HUD's archived FHA guidance says a well must meet local health rules, and a lender may ask for a water test (HUD).
Rainwater only: that same guidance says homes served by cisterns weren't acceptable for FHA mortgage insurance, except by waiver for some existing homes in areas where cisterns are typical, and never for new construction. Rules change, so ask your lender how it treats rainwater today, before you buy.
Insurance: whether a policy covers a well pump, tanks or lost water: varies, ask your insurance agent.

What to ask before you buy

Is a water utility already serving the land or nearby? Ask it for a written hookup cost.
Is there an existing well? Ask for the State Well Report (depth and pump test), its registration with the district, and recent lab results.
Which groundwater district covers the exact spot, and what is its drought stage today?
How deep are the neighbors' wells, and have any gone dry or weak in a drought?
Where would a well go, given the district's spacing from property lines, septic and other wells?
For rainwater: how big a roof will you build, is it metal, and where would a big level tank pad go?
Can a water truck reach the tank site in wet weather?
What lot size does the county want for septic with your water source?
Do the HOA or deed restrictions set rules on tank size, color or placement?
Will your lender and insurer accept the water source you plan?

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Common questions

Is a well or rainwater cheaper on raw land in the Texas Hill Country?

It depends on depth and on how much water you need. A national cost guide (HomeGuide, 2025) puts a complete well at about $12,000 to $32,000 for a 400-foot well and $15,000 to $40,000 for a 500-foot well. One Hill Country rainwater installer lists whole systems from about $15,000 to $30,000 for 5,000 to 16,000 gallons of storage, and more for bigger tanks. Get written quotes for your land. If a water utility line is already close, a hookup may cost less than either.

How deep are wells around here?

Across 22,436 state well records in Hays, Travis, Comal, Blanco, Caldwell and Bastrop counties, the typical well was drilled to about 420 feet, and half were between about 270 and 560 feet. It changes a lot by county and even mile to mile.

How much rainwater can a roof catch?

About 0.62 gallons per square foot of roof per inch of rain, before losses (the Texas Water Development Board's figure). Using TWDB's own Austin example (32 inches a year, 85% collected), a 2,000 sq ft roof catches about 33,700 gallons a year.

Do I need a permit for a household well?

Usually you have to register a new household well with the local groundwater conservation district before drilling, even when it's exempt from a pumping permit. Each district has its own forms and spacing rules, so call the district for your exact spot first.

Is rainwater safe to drink?

The Texas Water Development Board says collected rainwater is generally safe to drink after treatment, and that there are no federal or state quality standards for it. Its manual describes the common Texas setup: a 5-micron filter, a 3-micron charcoal filter, then an ultraviolet light. Ask your county health department about testing.

Can an HOA stop me from collecting rainwater?

Texas Property Code §202.007 says an HOA can't ban rain barrels or a rainwater system, but it can set some rules on where tanks go and how they look.

Where the numbers come from

Checked October 2026. Prices change, and national averages may not match the Hill Country. Where we couldn't find a solid number, we say "varies, ask."

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Please read: This guide is general information from public sources. It is not engineering, legal, lending or health advice, and it isn't a guarantee for any property. Talk to a licensed water well driller, a rainwater installer, the groundwater district, the county and your lender before you buy or build.