Can You Deepen an Existing Well? Options, Costs & Limitations

Your well is losing yield or running dry. Drilling a new well costs $20,000-$50,000. Can you just deepen the existing one instead? Sometimes yes, sometimes no. Here's how to know.

When Deepening Works

Good Candidates for Deepening

• Steel casing in good condition: No significant rust or holes
• Straight well bore: Drill bit can pass through without obstruction
• Adequate casing diameter: At least 6" casing allows standard drilling
• Known deeper water: Geological evidence suggests water at greater depth
• Relatively young well: Less than 30-40 years old typically

Poor Candidates

• Corroded or damaged casing: Can't maintain well integrity
• Small diameter (4" or less): Limits drilling equipment options
• Crooked well bore: Can't get drill bit through
• PVC casing: Can't drill through PVC safely
• Gravel-packed well: Disturbing the pack causes problems
• Already very deep: Diminishing returns past certain depths

The Deepening Process

Step 1: Well Inspection

Video camera inspection to assess casing condition, check for obstructions, and measure current depth.

Step 2: Pull the Pump

Remove existing pump, drop pipe, and wiring to access the well bore.

Step 3: Drill Deeper

Using a smaller bit that fits inside existing casing, drill to greater depth. Typically drill 50-200+ feet deeper.

Step 4: Install Liner (if needed)

A smaller-diameter liner may be installed in the deepened section.

Step 5: Develop and Test

Clean out drilling debris, develop the new zone, and test yield.

Step 6: Reinstall Pump

Set pump at new depth, reconnect, and test system.

Cost Comparison

Success Rates

Honest assessment: Deepening works about 60-70% of the time when conditions are favorable. Factors affecting success:

• Geology: Is there water-bearing rock below current depth?
• Regional water table: Is the entire aquifer declining?
• Well construction: Can the well physically be deepened?

We never guarantee results from deepening — no honest contractor can. But we can assess probability based on neighboring wells, geology, and your specific situation.

Alternatives to Deepening

Hydrofracturing

For wells in fractured rock, high-pressure water injection can open clogged fractures and improve yield without drilling deeper. Costs $5,000-$12,000 with 60-80% success rate.

Storage Tank System

If your well produces enough water over 24 hours but can't keep up with peak demand, a storage tank solves the problem without deepening. The well fills the tank slowly; a booster pump delivers water when needed.

Lower the Pump

If your well is deeper than the current pump setting, simply lowering the pump may access remaining water. This is the cheapest option when applicable ($500-$2,000).

New Well

Sometimes starting fresh is actually more economical than trying to salvage a marginal well, especially if the existing well has multiple problems.