How Deep Are Water Wells in North Texas?
Quick Answer
North Texas well depths range from 100–300 ft in sandy eastern counties to 400–700 ft in limestone-heavy western counties like Hood, Erath, and Parker.
One of the most common questions we get from North Texas property owners is: “How deep will my well be?” The answer depends heavily on where you are and what formation sits below your land. Here is a county-by-county breakdown of typical well depths across our 19-county service area.
North Texas Well Depths by County
| County | Target Aquifer | Typical Depth | Formation Character |
|---|---|---|---|
| Hunt | Nacatoch | 300–650 ft | Sandy; moderate depth and cost |
| Kaufman | Trinity (deep) | Variable; limited | Sparse groundwater; most on municipal supply |
| Rockwall | No productive aquifer | — | State planning value ~zero; properties use municipal water |
| Collin | Woodbine / Trinity | 150–350 ft | Sandy to limestone transition |
| Denton | Trinity (Paluxy) | 250–400 ft | Mixed limestone and sand |
| Tarrant | Trinity (Paluxy) | 200–350 ft | Mixed; variable by property |
| Dallas | Trinity (deep) | 2,000+ ft; rarely drilled | Nearly all properties on municipal supply |
| Grayson | Woodbine / Trinity | 150–350 ft | Sandy to limestone; varied |
| Fannin | Woodbine | 100–250 ft | Sandy; generally shallower |
| Cooke | Trinity / Woodbine | 300–500 ft | Harder limestone; moderate depth |
| Wise | Trinity (Paluxy) | 200–350 ft | Mixed limestone; moderate |
| Johnson | Trinity | 200–400 ft | Mixed limestone; Prairielands GCD |
| Ellis | Trinity | 200–400 ft | Limestone and chalk |
| Somervell | Trinity (Glen Rose) | 250–450 ft | Harder limestone |
| Parker | Trinity | 300–500 ft | Hard limestone; Upper Trinity GCD |
| Hood | Trinity | Varies by parcel | Hard to very hard limestone |
| Erath | Trinity (Twin Mountains) | 400–700 ft | Hard Glen Rose limestone over the producing sand; highest cost |
| Palo Pinto | Cross Timbers | 100–450 ft | Pennsylvanian sand and limestone; highly variable |
| Navarro | Nacatoch | 100–800 ft | Sandy; Carrizo-Wilcox in far southeast corner |
Depths represent typical residential production zones; specific properties may vary.
What Drives Depth Variation Within a County
Even within a single county, depths can vary by 50–150 feet between adjacent properties. The main factors:
Local structure. Aquifer formations aren’t flat — they dip, fault, and vary in thickness. A high point in the Woodbine formation means shallower water nearby; a trough means drilling deeper.
Well location relative to drainages. Properties near creek drainages and river valleys often have shallower alluvial water. This water is also more vulnerable to contamination and seasonal fluctuation.
What previous wells have found. The TWDB database contains well completion reports from decades of drilling across the region. A licensed driller who reviews these records before your project can narrow the expected depth range significantly.
Yield requirements. Sometimes the first productive zone isn’t adequate. A driller who encounters fractured limestone at 250 ft that yields only 1 GPM may continue to 350 ft to reach a more productive zone — even if the well could technically be completed shallower.
The Cost Implication of Depth
Every foot of depth costs money. The per-foot drilling rate in North Texas ranges from roughly:
| Formation Type | Per-Foot Drilling Cost |
|---|---|
| Sandy/alluvial (Woodbine) | $28–$40/ft |
| Mixed limestone/sand (Trinity upper) | $38–$50/ft |
| Hard limestone (Glen Rose / deep Trinity) | $48–$65/ft |
A 200 ft Woodbine well in Collin or Fannin County costs roughly $9,000–$16,000 complete. A 600 ft well in hard-limestone Hood County runs $33,000–$45,000. The formation matters as much as the depth.
Static Water Level vs. Total Depth
Total drilled depth is how far the borehole goes. Static water level is how far below the surface the water sits when the pump is off. These are different numbers.
Example: A 400 ft well in Wise County might have a static water level of 180 ft. The water fills the casing from 180 ft to the bottom at 400 ft — a 220 ft water column. The pump is set near the bottom to stay submerged even during heavy pumping.
During multi-year droughts, static water levels in North Texas can drop 20–60 ft. A well designed with adequate depth and pump setting survives drought; a well with the pump set too shallow runs dry.
How to Get a Depth Estimate for Your Property
The best depth estimate for your property comes from a licensed driller who:
- Knows your county and the general formation character
- Reviews TWDB well completion reports from your immediate area
- Assesses your site for local geology indicators
DFW Well Service provides free depth estimates based on TWDB well log review for properties throughout the 19-county service area. Call (940) 536-8560 or contact us online to get an estimate before committing to a project.