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How deep are water wells in Weir, Texas?

Home water wells in and around Weir, Texas are typically 315 to 515 feet deep (median 440 ft, 79 wells drilled in the last 10 years). Nearly all draw from the Washita and Fredericksburg groups (96%), according to the state's Northern Trinity and Woodbine model (TWDB). Estimated cost of a complete well at the median depth: $13,500 to $33,000.

Updated every day from Texas Water Development Board driller reports. Last update: November 11, 2026, using the state file of November 10, 2026.

See the wells and layers at an exact pointWilliamson County
What is under Weir, TexasUnderground column at the center of Weir: median well 440 ft, middle half 315 to 515 ft, water at 165 ft, and the layers of the state's model with their thickness.Above the Woodbine: 0 to 176 ftAbove the WoodbineWoodbine: 176 to 206 ftWashita and Fredericksburg: 206 to 747 ftWashita and Frederick…Upper Trinity: 747 to 1,577 ftUpper Trinitycontinues to 2,097 ft0200400600800ftGround level · 689 ft above sea levelMedian well: 440 ftWater standing in the well from 165 ftWater level165 ftMiddle half315–515 ftMedian well440 ft

Under Weir, Williamson County

Layers at the center of Weir from TWDB's Northern Trinity and Woodbine model (quarter mile cells, summarized here to about 1.3 miles), at true depth scale. The well and the water are the median of 79 real wells.

Home wells in and around Weir

Each dot is a home well from a state driller report, colored by depth. Tap one for its details and official report. Tap an empty spot to see what is under that point.

See underground

Well depth (ft)

  • <100
  • 100
  • 200
  • 300
  • 400
  • 600
  • 800+

Dashed line: Weir and about 2 miles around it

Key figures

Typical depth (middle half)
315 to 515 feet
Median depth
440 feet
Deepest 10% are past
614 feet
Water level (median)
165 feet
69 wells
Yield (median)
100 gpm
51 wells, gallons per minute
Wells used
79
In the last 10 years
Inside the city limits
4
the rest within 2 miles
All years on file
143
median 440 ft, since 2003
Confidence
Standard (30 or more wells)

When the wells were finished, the water stood a median 165 feet below the surface (69 wells), well above the bottom: the typical well holds about 275 feet of water.

What is under Weir, TexasUnderground column at the center of Weir: median well 440 ft, middle half 315 to 515 ft, water at 165 ft, and the layers of the state's model with their thickness.Above the Woodbine: 0 to 176 ftAbove the WoodbineWoodbine: 176 to 206 ftWashita and Fredericksburg: 206 to 747 ftWashita and Frederick…Upper Trinity: 747 to 1,577 ftUpper Trinitycontinues to 2,097 ft0200400600800ftGround level · 689 ft above sea levelMedian well: 440 ftWater standing in the well from 165 ftWater level165 ftMiddle half315–515 ftMedian well440 ft
Layers at the center of Weir from TWDB's Northern Trinity and Woodbine model (quarter mile cells, summarized here to about 1.3 miles), at true depth scale. The well and the water are the median of 79 real wells.

Which formation do wells in Weir draw from?

Nearly all draw from the Washita and Fredericksburg groups (96%), according to the state's Northern Trinity and Woodbine model (TWDB).

Layer (state's model)ShareWellsTypical depth (ft)
Washita and Fredericksburg96%76318–510
Above the Woodbine3%2—
Upper TrinityPaluxy and Glen Rose1%1—

For 82% of these wells the report says where the water enters and we use the middle of that interval; for the rest we use the bottom of the hole, which tends to read one layer too deep.

The layers under the center of Weir

From the state's model, at 689 feet above sea level. These are the model's depths at that one point, not those of any particular lot.

Depths in feet below ground.
Layer (state's model)Top (ft)Bottom (ft)Thickness (ft)
Above the Woodbineshale, chalk and marl0176176
Woodbinesandstone with shale17620630
Washita and Fredericksburglimestone, marl and clay206747541
Upper Trinitysandstone, limestone and marl7471,577830
Lower Trinitysandstone with shale and limestone1,5772,097521

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 and around Weir are getting deeper. For reference, the median was 400 feet in 2001 to 2005 (19 wells) and 470 feet in 2021 to 2025 (41 wells).

PeriodMedian depth (ft)Wells
2001–200540019
2006–201046021
2011–201533518
2016–202034040
2021–202547041
2026under 10 wells4

What a well costs in Weir

At the median depth for Weir (440 feet), a complete home well would cost roughly $13,500 to $33,000: $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 (315 to 515 feet) the range runs from $10,500 to $37,500. 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.

Where it sits

Nearby places

Median depth of home wells in each place.

All Texas cities and towns

Common questions

How deep do you have to drill a well in Weir, Texas?

Home water wells in and around Weir, Texas are typically 315 to 515 feet deep (median 440 ft, 79 wells drilled in the last 10 years). One in ten goes past 614 feet. The depth a given tract needs depends on where it sits and what layers the driller hits.

What aquifer or formation do wells in Weir draw from?

Nearly all draw from the Washita and Fredericksburg groups (96%), according to the state's Northern Trinity and Woodbine model (TWDB). This is an estimate from the state's regional model, not a survey of the lot.

How much does a water well cost in Weir?

At the median depth (440 feet), a complete well would cost roughly $13,500 to $33,000, by TerraFunded's estimate from published Texas driller prices. The real price comes from a licensed driller's quote.

How deep is the water in Weir?

When the wells were finished, the water stood a median 165 feet below the surface (69 wells), well above the bottom: the typical well holds about 275 feet of water. The level moves with drought and from one well to the next.

Do I need a permit to drill a well in Weir?

In the state's boundary file (current as of November 2019) no groundwater conservation district covers Weir. Districts created or enlarged since then are missing from that file, so confirm with the county or TWDB before drilling. Anywhere in Texas the well must be drilled by a licensed driller, who files the report with the state.

How these numbers are made

We count new and replacement domestic (home) wells whose coordinates fall inside the place boundary or within 2 miles of it. 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 82% of these wells the report says where the water enters and we use the middle of that interval; for the rest we use the bottom of the hole, which tends to read one layer too deep.

How well it works: In 7,977 wells in the area of the state's Northern Trinity and Woodbine model (North and Central Texas) where the State of Texas recorded the aquifer, our estimate of the formation the well draws from names the same layer of the state's model in about 74% of them, and that layer or the one next to it in at least 95%; among the 3,130 of those wells that the state places in a Trinity layer (Paluxy to Hosston) it is about 56%.

  • The layers come from the Texas Water Development Board's Northern Trinity and Woodbine model, with quarter mile cells, summarized here to about 1.3 miles. It is a regional model, not a survey of any lot: between one model point and the next, the real depth of each layer can differ.
  • In this model every layer is at least 30 feet thick, even where the real rock is thinner or missing. Thin layers and the edges of the model are approximate.
  • Inside the Trinity this atlas does not name single model layers: it groups the Paluxy and Glen Rose (upper Trinity) and groups the Hensell, Pearsall and Hosston (lower Trinity, Twin Mountains and Travis Peak), because the check against the state's codes shows the method cannot separate them reliably.
  • "Near or below the base of the Trinity" means the well reaches the bottom of the model or passes it, often by tens of feet. Older rock that the model does not include may lie there.
  • 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/places/weir-tx. License CC BY 4.0. https://doi.org/10.5281/zenodo.24126380.

Sources