The deepest records in TWDB groundwater data are not simple domestic-well bragging rights. They are oil tests, plugged-back holes, hot flowing wells, salty intervals, and a lesson in why total depth can fool land buyers.
The deepest Texas water-well records do not look like your neighbor’s private well. That is exactly why they are useful.
The seven deepest Texas water-well records are less about homeowners drilling impossibly deep wells and more about how messy old well records can be. Total depth is not the same as usable water depth.
The list is real, but the headline needs a warning label
The Texas Water Development Board Groundwater Database is one of the best starting points for understanding old Texas well records. It includes selected water wells, springs, water levels, water quality records, and oil or gas tests that matter to groundwater interpretation. When we sorted the TWDB GWDB by recorded well depth, the top of the list got strange fast.
The deepest records tagged as withdrawal-of-water wells are not ordinary domestic wells. Several are old oil tests. Some were plugged back and converted. Some produced hot or salty water. Some list a total drilled hole thousands of feet deeper than the water sands noted in the remarks.
That makes the story more useful, not less. It shows exactly why a buyer should not grab a single well-depth number and treat it like a drilling estimate.
Depth Infographic
The top seven deepest water-well records we found
| Rank | County | Depth | Record | Why it is interesting |
|---|---|---|---|---|
| 1 | Brooks | 11,000 ft | King Ranch, Patricio Pasture #4, TWDB 8464804 | The remarks say the hole was drilled to 11,000 feet, but water-sand chloride interpretation was to 928 feet. That is the whole article in one record. |
| 2 | Brooks | 9,000 ft | King Ranch, Quiteria Pasture #3, TWDB 8708803 | Another King Ranch-area deep hole where the water interpretation is far shallower than total drilled depth. |
| 3 | Presidio | 8,815 ft | I. T. May / Swafford No. 1, TWDB 5143101 | An oil test with reported hot flowing water around 2,868 feet and high dissolved solids. Deep water is not automatically good water. |
| 4 | Jeff Davis | 8,630 ft | SI Bar KC Ranch / Rousanville No. 1, TWDB 5201402 | Drilled to Devonian formation as an oil test, then plugged back to be converted to a water well. |
| 5 | Kenedy | 8,111 ft | King Ranch / C. M. Armstrong #3, TWDB 8810103 | The record notes a deep hole, but water-sand chloride interpretation to 1,380 feet. |
| 6 | Cass | 7,055 ft | Allday Well 1, TWDB 3507302 | Tagged as withdrawal of water, but the remarks say oil test. That caveat matters. |
| 7 | Washington | 7,029 ft | W. H. Buck, TWDB 5947901 | A deep legacy record that demonstrates why source and purpose matter as much as the number. |
Seven records, seven different stories
The table gives the quick answer. The better article is in the notes. Each of these records teaches a different way a deep Texas well number can mislead someone who is trying to understand a real property.
This is the record that makes the whole list feel like a trick question. The database depth says 11,000 feet, which sounds like a monster water well. But the remark is the important part: the log in the file runs to a shallower interval, and the water-sand chloride interpretation is noted to 928 feet. In plain English, the hole may be extremely deep, but the water story is not simply an 11,000-foot household supply well.
For a land buyer, that distinction matters. A total drilled depth can preserve information about geology, exploration, and historical drilling. It does not automatically tell you where a domestic well should be completed, what water quality will be, or what the usable aquifer interval looks like. This record is a warning against treating a database depth column like a drilling recommendation.
The second-deepest record reinforces the same lesson from a different King Ranch-area hole. The recorded depth is 9,000 feet, but the water-sand chloride interpretation noted in the record is far shallower than the total hole. That does not make the record bad. It makes it more interesting, because it separates the drilled-hole story from the water-bearing-interval story.
When two nearby records both show that pattern, the smart move is not to average them and assume a buyer needs a 10,000-foot well. The smart move is to ask what the records were originally drilled for, which intervals were tested or interpreted for water, and whether the water in those intervals was usable for the intended purpose.
The Presidio County record is one of the most useful because it has a real story inside it. It is tied to an oil-test context and notes reported flow around 2,868 feet, high dissolved solids, and hot water temperatures. That combination is exactly why deep groundwater records need interpretation. Flowing water can be impressive and still be a poor fit for ordinary domestic use.
This is the part most simple listicles would miss. The question is not only, “How deep was it?” The better questions are: What was the water temperature? What was the dissolved-solids load? Was the water usable, brackish, geothermal, or mostly a data point from an exploration hole? For rural property decisions, water quality can matter as much as depth.
The Jeff Davis County entry shows how old oilfield and groundwater records can overlap. The record notes a hole drilled to a deep formation as an oil test, then plugged back for conversion to water use. That is not the same thing as a modern driller showing up to put in a standard ranch or household well from scratch.
Plugged-back wells can be legitimate, but the phrase should slow the reader down. It raises questions about original purpose, casing, completion, intervals left open, water quality, and long-term suitability. If a nearby property has records like this, a buyer should not stop at the depth number. The conversion history is part of the risk file.
The Kenedy County record again carries the King Ranch pattern: a very deep total hole and a water interpretation that is much shallower. It is useful because it shows the pattern is not a one-off typo. In parts of South Texas, legacy records can reflect exploration history, salinity interpretation, and groundwater clues all packed into one line item.
A practical well owner does not need the romance of an 8,111-foot number. He needs to know what interval actually produced or could produce water, what that water was likely to contain, and whether local conditions make it a practical supply. This record is another reminder that the deepest-looking entry may be less useful than a shallower, cleaner, better-documented nearby domestic or stock well.
The Cass County record is a good example of why database labels and record remarks have to be read together. It is tagged in a way that brings it into a withdrawal-of-water pull, but the remark indicates an oil-test context. That does not mean it should be ignored. It means it should be handled carefully.
East Texas has plenty of real groundwater stories, especially around the Carrizo-Wilcox and related aquifer systems. But a 7,055-foot record with an oil-test caveat should not be used as a simple domestic-well benchmark. The responsible use is as a clue to subsurface history, not a quote for what a water well should cost or how deep a household well should be.
The Washington County entry rounds out the list with another deep legacy record where the source and purpose matter. A depth field can survive cleanly in a database even when the historical context around the hole is more complicated than a modern buyer expects.
The lesson is not that Washington County buyers should expect 7,000-foot water wells. The lesson is that old records can carry useful clues and bad shortcuts at the same time. A good review checks the record source, the well use, the aquifer or formation field, the water-quality notes, and nearby modern wells before turning one old number into a plan.
Why this matters before drilling
A normal Texas domestic well is not planned by copying the deepest record in the county. A useful well record tells a story: where the well is, which aquifer or formation it reached, what use it served, when it was drilled, who drilled it, what depth was actually completed, what water quality looked like, and whether the record was a household well, industrial supply, oil test, public supply well, stock well, or something else.
That distinction is where buyers get into trouble. A listing might say water is available. A neighbor might say wells are deep. A county page might show a broad average. None of those replaces record-level due diligence.
For these seven records, the most useful lesson is not that Texas wells should be 7,000 to 11,000 feet deep. The useful lesson is that total depth can be misleading. Some records are about geology. Some are about oilfield history. Some are about hot or salty water. Some are about a deep borehole that only helps interpret a much shallower water interval.
Look at nearby records by use, aquifer, date, depth, and notes.
PlanningUse Pre-Drill before a drilling budgetDepth only becomes useful when it is tied to local context.
Bottom line
The deepest water-well records in Texas are not clean bragging rights. They are warning labels. They show why groundwater data is powerful only when somebody reads the fine print.
Before buying land, drilling a well, or assuming one nearby record tells the whole story, check the purpose of the well, the usable water interval, the local aquifer, the GCD, and the water-quality clues. The number at the bottom of a record is only the beginning.
- Local TWDB GWDB download,
WellMain.txt, sorted byWellDepthwithWellTypecontaining withdrawal of water. - Texas Water Development Board Groundwater Database reports.
- Texas Water Development Board groundwater data.
Media, source, or interview requests: contact TurnKey Wells about Texas groundwater, private wells, aquifers, and water-use research.