How deep are water wells in McMullen County, Texas?

Half of the home water wells drilled in McMullen County since 2001 are between 221 and 539 feet deep. The median is 360 feet, based on 54 driller reports filed with the state. Drillers measured the water standing a median 145 feet below the surface (52 wells). That is deeper than the Texas median of 250 feet.

Updated every day from Texas Water Development Board driller reports. Last update: November 10, 2026, using the state file of November 9, 2026. These are depths of real wells drilled nearby, not a promise about any property. Groundwater can change over short distances and with drought. A licensed water well driller can tell you what to expect on a specific tract.

Key figures

Typical depth (middle half)
221 to 539 ft
Median depth
360 feet
Deepest 10% are past
2,806 feet
Water level (median)
145 feet (52 wells)
Yield (median)
20 gallons per minute (12% pump-tested)
Wells used
54
Period
Since 2001
Latest report
July 4, 2026
Depth rank
92 of 245 (1 = deepest)
Confidence
Standard

How deep the wells are

Number of home wells by depth, last 10 years (or since 2001 where wells are few).

Depth (ft)Wells
0 to 501
50 to 1002
100 to 1503
150 to 2006
200 to 2505
250 to 3005
300 to 3504
350 to 4005
400 to 4505
450 to 5002
500 to 5504
550 to 6003
650 to 7001
700 to 7502
2,000 to 5,000+6

Are wells in McMullen County getting deeper?

McMullen County does not have enough domestic wells in both 2003 to 2007 and 2021 to 2025 (at least 30 in each) to compare. Read the 20-year study.

Aquifers under the county

The Texas Water Development Board maps the Carrizo-Wilcox, a major aquifer, below other rock (subsurface) across 76% of the county; the Gulf Coast, a major aquifer, at the surface (outcrop) across 25% of the county; the Yegua-Jackson, a minor aquifer, under 64% of the county; the Queen City, a minor aquifer, under 22% of the county; the Sparta, a minor aquifer, under 5% of the county.

What a well costs in McMullen County

At the median depth for McMullen County (360 feet), a complete home well (drilling, casing, pump, pressure tank and hookup at the well) would cost roughly $11,500 to $28,000, by TerraFunded's estimate from published Texas prices. Trenching and the line to the house are extra. Get quotes from at least two licensed drillers.

Neighboring counties

Common questions

How deep do I need to drill a well in McMullen County?

The middle half of home wells drilled there are 221 to 539 feet deep; one in ten goes past 2,806 feet. The depth a given tract needs depends on where it is and what layers the driller hits.

How much does a water well cost in McMullen County?

At the median depth (360 feet), a complete well would cost roughly $11,500 to $28,000 by TerraFunded's estimate from published Texas driller prices ($25 to $60 per foot plus pump and equipment). The real price comes from a driller's quote.

How much water does a well produce in McMullen County?

Drillers reported a median of 20 gallons per minute (50 wells). Only 12% of those figures come from a pump test; the rest are the driller's estimate, so treat them as a guide.

Are wells in McMullen County getting deeper?

McMullen County does not have enough domestic wells in both 2003 to 2007 and 2021 to 2025 (at least 30 in each) to compare.

How do I see the well report for a property or a neighbor's well?

Every well drilled in Texas since 2001 has a public driller's report. On this page's map, tap a well to open its official report on the state's site, or look it up by location in the TWDB viewer.

How to read these numbers

Figures cover new and replacement domestic (home) wells, from the reports licensed drillers file with the state. Read the full methodology. Download the county table (CSV).

How to cite: TerraFunded Texas Well Atlas, from Texas Water Development Board driller reports (data as of November 9, 2026). https://terrafunded.com/wells

Sources

All counties