What Is the Difference Between Drilled, Driven, and Dug Wells?
Quick Answer
Drilled wells reach deep aquifers with a rotary rig. Driven wells push pipe into shallow sand. Dug wells are pits. Only drilled wells work in North Texas.
The terms drilled, driven, and dug refer to three fundamentally different ways of reaching groundwater. In North Texas, only one of these approaches is practical — but understanding the differences helps property owners evaluate what they have on their land and what any new well project will actually involve.
Side-by-Side Comparison
| Drilled Well | Driven Well | Dug Well | |
|---|---|---|---|
| Construction method | Rotary or percussion drill rig | Driving pointed pipe into soil | Hand or machine excavation |
| Typical depth | 150–1,000+ ft | Under 50 ft | Under 30 ft |
| Diameter | 4–8 inches | 1.25–2 inches | 3–6 feet |
| Yield potential | 3–20+ GPM | Under 1–2 GPM | Very low; variable |
| Casing | Steel or PVC, cement-grouted | Steel pipe | Brick, stone, or concrete rings |
| Contamination risk | Low (depth + grouting) | High (shallow) | Very high (open, shallow) |
| Applicable in North Texas | Yes — standard method | No | No |
| Licensed driller required | Yes (Texas law) | N/A | N/A |
| Permit required | Yes (in GCD counties) | N/A | N/A |
Drilled Wells: The Modern Standard
A drilled well begins with a rotary rig that turns a tri-cone or PDC drill bit against rock and soil, circulating drilling fluid to remove cuttings. Once the target aquifer is reached, steel or PVC casing is run to the surface and cement is pumped into the annular space between the casing and the borehole wall — creating a sealed water column protected from the surface.
What makes drilled wells superior for North Texas:
- Depth — only method that reaches the Trinity and Woodbine aquifers at 150–600 ft
- Sealed construction — grouting prevents surface water from migrating down the outside of the casing
- Yield — larger diameter and proper well development produce 3–20 GPM in most formations
- Longevity — properly constructed drilled wells routinely last 30–50+ years
Driven Wells: A One-Trick Method
A driven well consists of a well point — a torpedo-shaped screen attached to a section of small-diameter steel pipe — hammered or pushed into saturated sandy soil. As each pipe section is driven deeper, additional sections are threaded on above. The result is a small-diameter pipe in the ground, open at the screened tip.
This approach only works when all of the following are true:
- The water table is less than 25–35 feet below the surface (suction-lift limit of a pump)
- The soil is loose, uniformly sandy or gravelly — no clay, caliche, or rock
- Very low yield is acceptable
In North Texas — where the water table is often 50–150 ft below the surface, clay and caliche dominate the shallow geology, and limestone formations require actual drilling — driven wells simply cannot be installed. They are not a cost-saving shortcut; they are not viable at all.
Dug Wells: An Obsolete Approach
A dug well is an excavated pit — historically dug by hand with shovels and buckets, now sometimes machine-excavated with a backhoe — lined with stone, brick, or precast concrete rings to prevent collapse. Water seeps into the bottom of the pit from the surrounding saturated zone.
Dug wells were once common on Texas farmsteads because they required no specialized equipment. The problems are substantial:
Contamination vulnerability. A large-diameter open pit collects whatever runs into it — surface water, insects, small animals. A single heavy rain event can introduce bacteria, nitrates, and chemical contamination. Dug wells in Texas have caused documented disease outbreaks.
Shallow depth. A dug well rarely reaches more than 30–40 feet. During drought, the water table drops and the dug well dries up. North Texas experiences multi-year drought cycles that regularly lower water tables beyond dug-well range.
Modern codes prohibit new construction. Texas TDLR construction standards require casing, grouting, and proper wellhead protection — requirements that a dug well cannot meet. No new dug wells are permitted for domestic water supply.
What to Do with an Old Dug or Driven Well
If you purchase a rural property with an existing dug well or old driven well:
- Do not use it for drinking water without lab testing (coliform, nitrates, metals at minimum)
- Have a licensed driller inspect the structure
- Determine whether the well meets Texas standards or should be decommissioned
- Consider drilling a new properly cased well to replace it
Texas requires proper decommissioning (plugging and grouting) of abandoned water wells — simply filling a dug well with dirt is not compliant.
DFW Well Service evaluates existing well structures and drills new wells throughout the 19-county North Texas service area. Call (940) 536-8560 to discuss your property.