How we measure Texas well depth

Updated every day from Texas Water Development Board driller reports. Last update: November 10, 2026, using the state file of November 9, 2026.

The data

The Texas Water Development Board's Submitted Driller's Reports database. Every licensed driller files a report for each new well since 2001. TWDB publishes the full database and rebuilds it nightly. We use the file of November 10, 2026, with 714,471 reports.

We never load owner or driller names or addresses, even though the state file includes them.

Which reports count

County figures use new and replacement domestic (home) wells: 291,634 with a valid depth. Monitoring wells, soil borings, injection, geothermal and oilfield wells are left out. They are most of the file, but they don't tell you how deep a water well is.

Depth is the deepest borehole bottom on the report. A depth under 10 feet or over 5,000 feet is treated as an entry error. Water level is the report's first measurement (static water when the well was finished), dropped if negative or deeper than the well. Yield is the report's best test, preferring a pump test over an estimate.

How each county is figured

We use domestic wells finished in the last 10 years when there are at least 30; otherwise all since 2001. We publish the median (half the wells are deeper, half shallower), the middle half (25th to 75th percentile) and the deepest 10%.

Confidence: standard with 30 or more wells, "few wells" with 10 to 29, and no figure under 10. With this cut, 245 counties have a standard figure, 4 have few wells and 5 have no figure.

The county is the one the driller reported. We also check that the coordinates fall inside it; the map shows only wells whose coordinates match.

The point search

We look for real domestic wells around the point, starting at 2 miles and widening to 3, 5, 10 and 15 until there are at least 10. We show the median, the middle half, water level, yield, the distance to the nearest well and a reliability rating.

Everything is refreshed every night: the well table behind this search and the county figures. Every page shows the date of its last update and of the state file it uses, so it can be cited.

The 20-year comparison

We compare domestic wells finished in 2003 to 2007 with 2021 to 2025, in every county with at least 30 wells in each period. A 95% confidence interval for the difference in medians comes from 2,000 bootstrap resamples. We only say "deeper" or "shallower" when that interval excludes zero and the change is at least 10%. For the water level we require at least 5 feet and 10%.

New wells keep moving to different places, so we also compare the same areas: 0.1 degree cells (about 6 miles) with at least 10 wells in each period.

Deeper wells don't always mean the water dropped: a driller may go for another aquifer, better water or more reserve. That is why we also compare the water level measured when each well was finished, which also moves with drought.

Rock layers in the 3D view

Drillers describe each layer in their own words. We group them with fixed rules (the first word that names a material: "sandy clay" is clay) into 8 classes. The rules classify 96.9% of layers. A layer with the word "water" or "wet" is marked water-bearing.

The 3D view stretches depth so the wells are visible and never draws a continuous water table between wells: only what each driller reported. The blue column is the water standing in each well, from the level the driller measured when it was finished down to the bottom.

Aquifers

We use TWDB's official maps of major aquifers (updated December 2006) and minor aquifers (December 2017). For each county we measure how much of its area sits over each aquifer. The map shows where an aquifer is mapped; it does not promise water at a point.

Cost estimate

This is TerraFunded's estimate, not a quote: depth × $25 to $60 per foot (drilling, casing and seal) plus $2,500 to $6,500 for the pump, pressure tank, controls, wiring at the well, permit and a first water test. The ranges come from published Texas driller prices and cost guides (reviewed November 2026). Trenching, the line to the house and water treatment are not included.

What this data can't tell you

There are only wells where someone drilled. An area without wells doesn't mean there is no water. Reports before 2003 are in a separate (paper) state system and are not here. Drillers type the coordinates and the state does not verify them. Water quality is not part of these reports.

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.

License, downloads and corrections

The derived figures are published under CC BY 4.0: use them with the credit "TerraFunded Texas Well Atlas, from TWDB data" and a link to this page. If you find a mistake, write to us and we will fix it in the next update.

Price sources

Sources

Texas water wells