Pecos Valley Aquifer: how deep the wells are
Home water wells that draw from the Pecos Valley Aquifer in the Panhandle, the South Plains and the Permian Basin are typically 131 to 267 feet deep (median 180 ft, 90 wells drilled in the last 10 years). In the state's model it is sand, gravel and clay. It carries the most weight in Reeves County (93% of its wells) and Winkler County (60% of its wells). Estimated cost of a complete well at the median depth: $7,000 to $17,500.
This page covers only the northern edge of the Pecos Valley Aquifer that falls inside the state's High Plains model (Reeves, Ward and Winkler counties), so it is kept out of search engines. The aquifer runs on to the south and west, where this atlas has no layered model yet.
Updated every day from Texas Water Development Board driller reports. Last update: November 11, 2026, using the state file of November 10, 2026.
Under Town of Pecos, Reeves County
Dot: median. Bar: middle half (25th to 75th percentile). Counties with the most wells in this layer.
Digging in…
What this layer is
The Pecos Valley Aquifer is sand, gravel and clay that filled low basins along the Pecos River. In the area of this model it is the shallow aquifer of Ward and Winkler counties and the nearby part of Reeves, Loving, Crane and Pecos counties, where home wells draw from it.
Units the model puts in this layer: Cenozoic alluvium of the Pecos Valley (Ward, Winkler, Crane, Reeves and Pecos counties).
Checked against the state's own aquifer codes: where our method names this group, the state agrees in 96% of 871 wells.
Source of the layers: TWDB's High Plains Aquifer System model, with half mile cells, read here on a grid of about 1.2 by 1.4 miles.
Key figures
- Typical depth (middle half)
- 131 to 267 feet
- Median depth
- 180 feet
- Deepest 10% are past
- 350 feet
- Water level (median)
- 78 feet
- 19 wells
- Yield (median)
- 25 gpm
- 21 wells, gallons per minute
- Wells used
- 90
- In the last 10 years
- All years on file
- 173
- median 200 ft, since 2001
- Confidence
- Standard (30 or more wells)
Counties where homes draw from this layer
Only counties with at least 10 wells in the layer. The share is of the county's wells that the model covers.
| County | Median depth (ft) | Wells | Share of the county's wells |
|---|---|---|---|
| Reeves County | 230 | 42 | 93% |
| Ward County | 140 | 23 | 25% |
| Winkler County | 179 | 18 | 60% |
Places where it is the main layer
- Town of Pecos 200 ft
Where it sits among the model's layers
From top to bottom, with the median depth of the home wells that draw from each:
| Layer (state's model) | Rock | Median depth (ft) | Wells |
|---|---|---|---|
| Ogallala Aquifer | sand, gravel, silt and caliche | 161 | 12,389 |
| Pecos Valley Aquifer | sand, gravel and clay | 180 | 90 |
| Edwards-Trinity and Rita Blanca (Cretaceous rock under the Ogallala) | sand, sandstone and limestone | 163 | 5,214 |
| Dockum Group | red mudstone, sandstone and conglomerate | 250 | 6,009 |
Depth over time
There are not enough wells in both 2003 to 2007 and 2021 to 2025 (at least 30 in each) to say with confidence whether wells in this layer are getting deeper. For reference, the median was 200 feet in 2006 to 2010 (23 wells) and 200 feet in 2021 to 2025 (36 wells).
| Period | Median depth (ft) | Wells |
|---|---|---|
| 2001–2005 | under 10 wells | 6 |
| 2006–2010 | 200 | 23 |
| 2011–2015 | 240 | 47 |
| 2016–2020 | 160 | 55 |
| 2021–2025 | 200 | 36 |
| 2026 | under 10 wells | 6 |
Common questions
How deep is a well in the Pecos Valley Aquifer?
Home water wells that draw from the Pecos Valley Aquifer in the Panhandle, the South Plains and the Permian Basin are typically 131 to 267 feet deep (median 180 ft, 90 wells drilled in the last 10 years).
What is the Pecos Valley Aquifer?
The Pecos Valley Aquifer is sand, gravel and clay that filled low basins along the Pecos River. In the area of this model it is the shallow aquifer of Ward and Winkler counties and the nearby part of Reeves, Loving, Crane and Pecos counties, where home wells draw from it.
How deep does the water stand in these wells?
When the wells were finished, the water stood a median 78 feet below the surface (19 wells), well above the bottom: the typical well holds about 102 feet of water.
What a well in this layer costs
At the median depth for this layer (180 feet), a complete home well would cost roughly $7,000 to $17,500: $25 to $60 per foot for drilling, casing and seal, plus $2,500 to $6,500 for the pump, pressure tank, controls and hookup at the well. Across the whole middle half of depths (131 to 267 feet) the range runs from $6,000 to $22,500. This is TerraFunded's estimate from published Texas prices, not a quote, and it leaves out trenching and the line to the house. Get prices from at least two licensed drillers.
How these numbers are made
We count new and replacement domestic (home) wells with a valid depth on their report. We use the last 10 years when there are at least 30 wells; otherwise all since 2001. The median is the middle well and the middle half runs from the 25th to the 75th percentile.
To tell which layer a well draws from, we take the ground elevation at its location, subtract the depth of the interval where water enters (or the bottom of the hole when the report does not give one) and see which layer of the state's model that point falls in.
For 94% of these wells the report says where the water enters (the screen or the open hole), and we use the middle of that interval.
How well it works: In 22,814 wells in the Texas part of the state's High Plains Aquifer System model (the Panhandle, the South Plains and the Permian Basin) where the State of Texas recorded the aquifer, the formation our method says the well draws from (as grouped on these pages) is the one the state recorded in about 75% of them; when it names the Dockum (4,542 wells), the state's record agrees only about 33% of the time, and most of the others are recorded as Ogallala wells.
- The layers come from the Texas Water Development Board's High Plains Aquifer System model, with half mile cells, read here on a grid of about 1.2 by 1.4 miles. It is a regional model, not a survey of any lot.
- The state's model has half mile cells; we read it on a grid of about 1.2 by 1.4 miles, Texas part only. Layers from version 1.01 (2015); the 2025 extension (1.02) did not change them. It is not a survey of any lot, so we give ranges.
- Figures go by four groups: Ogallala; Pecos Valley; Edwards-Trinity and Rita Blanca (Cretaceous rock under the Ogallala; the Rita Blanca alone matched the state 19%); Dockum (upper and lower together: the state's codes almost never say which). The Edwards-Trinity group joins three aquifers in different places (High Plains around Lubbock, Plateau around Midland and Odessa, Rita Blanca in Dallam and Hartley): county and place pages name the local one where they can.
- Dockum: when our method names the Dockum, the state's record agrees only 33% of the time over all years (61% for wells with a screened interval, which is 93% of home wells of the last 10 years); most of the rest are recorded as Ogallala wells. The median well we put in the Dockum ends about 18 ft under the base of the Ogallala as the model draws it. So these pages say "at or just below the base of the Ogallala, in the top of the Dockum", never a certain formation. The state's own 2025 report on this model says depth alone overstates the upper Dockum.
- "Near or below the base" means the well ends near or below the base of the Dockum, or of the Ogallala where there is no Dockum (Permian red beds; Gray, Carson, Donley, Moore and north Potter counties). Half of these wells end within about 51 ft of the base, and the state usually records them as Ogallala or Dockum wells. That is not an error: the model simply ends there.
- For old wells without a screened interval (bottom of the hole) the method is only a little better than always saying Ogallala (65% against 58%); with an interval it is 89% against 80%. Figures over all years carry that weakness; last 10 years figures rest almost entirely on intervals.
- We never use the model's water levels. The water level on this page is the one each driller measured when the well was finished.
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.
Read the full methodology · Download the data (CSV, CC BY 4.0)
How to cite
TerraFunded (2026). Texas Well Atlas: Underground. From Texas Water Development Board driller reports and groundwater availability models (data as of November 10, 2026). https://terrafunded.com/wells/formations/pecos-valley. License CC BY 4.0. https://doi.org/10.5281/zenodo.24126380.
Sources
- Submitted Driller's Reports database, Texas Water Development Board (TWDB) (file of November 10, 2026)
- Numerical Model Report for the High Plains Aquifer System Groundwater Availability Model. Deeds, N.E., and Jigmond, M. (INTERA Incorporated), for the Texas Water Development Board; extension through 2020 by Cawthon, T., and Wade, S. (TWDB, 2025), 2015, GAM v1.01 (layers unchanged in the 2025 extension, version 1.02). TWDB groundwater availability model.
- Ground elevation: Terrain Tiles (Mapzen), Registry of Open Data on AWS
- TWDB well report viewer (each well's official report)