Deepen Existing Well Cost

If your well is producing less water than it used to, or if it's running dry during peak demand periods, deepening the existing well may be a cost-effective solution compared to drilling a new one. As experienced well contractors serving Southern California for over 30 years, we've deepened hundreds of wells across San Diego, Riverside, and San Bernardino counties. Here's what you need to know about the costs and process.

Average Cost to Deepen a Well

Deepening an existing well typically costs $8,000 to $25,000, significantly less than drilling a new well from scratch. The final cost depends on how much deeper you need to go, the geology you'll encounter, and whether the existing casing can be reused.

What's Included in Well Deepening Cost

A complete well deepening project includes:

• Initial assessment: Video inspection or mechanical evaluation of existing well condition
• Pump removal: Pulling the existing submersible pump, drop pipe, and wiring
• Drilling deeper: Extending the well bore to reach additional water-bearing formations
• Casing extension: Adding new steel casing sections if needed, or using existing casing if structurally sound
• Re-grouting: Sealing the extended well to California standards
• Pump replacement: Installing a deeper-rated pump (usually required when going significantly deeper)
• New drop pipe and wiring: Longer sections to reach the new depth
• Well development: Cleaning out drilling debris and stimulating water flow
• Water testing: Ensuring water quality remains good
• Permit modifications: Filing updated well completion reports with the county

Factors Affecting Well Deepening Cost

1. How Much Deeper You Need to Go

This is the primary cost driver. Drilling is typically charged at $75-$150 per additional foot depending on the geology.

• Minor deepening (50-75 feet): Often sufficient when the water table has dropped slightly
• Moderate deepening (75-150 feet): Reaching a deeper water-bearing zone
• Major deepening (150+ feet): May approach the cost of a new well; careful evaluation needed

2. Condition of Existing Casing

The structural integrity of your current casing affects feasibility and cost:

• Good condition steel casing: Can often drill through and extend downward – lower cost
• Corroded or damaged casing: May require abandoning the old casing and installing entirely new casing – higher cost
• PVC casing: Cannot be drilled through; typically requires new well – not a candidate for deepening

Video inspection ($300-$500) before committing to deepening can save you from unexpected issues.

3. Geology Below Current Well Depth

What you'll drill through affects both cost and success:

• Sedimentary rock or alluvium: Easier drilling, lower per-foot costs
• Granite or hard rock: Common in East San Diego County – slower drilling, higher costs, may require specialized bits
• Unknown geology: Reviewing well logs from nearby properties helps predict conditions

4. New Pump Requirements

Going deeper almost always requires a new pump:

• Higher pressure rating: Pumps must lift water from greater depths
• Larger motor: May need 1.5 HP or 2 HP instead of 1 HP
• Longer drop pipe and wiring: Proportional to depth increase
• Pump cost: Budget $1,500-$3,500 for a quality submersible pump rated for the new depth

5. Well Diameter

Existing well diameter affects options:

• 6-inch or larger wells: Easier to deepen, standard equipment fits
• 4-inch wells: More challenging, may limit deepening options or require specialized smaller drilling equipment

When Does Deepening Make Sense?

The Well Deepening Process

Here's what to expect when we deepen your well:

1. Assessment and Planning: We inspect your existing well, review nearby well logs, and determine the target depth for adequate water yield.
2. Permits: File a modification permit with the county environmental health department.
3. Mobilization: Bring in the drilling rig and equipment.
4. Pump Removal: Pull out the existing pump, drop pipe, and electrical components.
5. Drilling: Extend the well bore to the target depth, using the appropriate drilling method for the geology.
6. Casing and Grouting: Extend casing if needed and properly seal the well.
7. Well Development: Pump out drilling fluids and develop the well to maximize water flow.
8. Install New Pump: Set a pump rated for the new depth with appropriate drop pipe and wiring.
9. Testing: Run the system to verify flow rate, water quality, and system performance.
10. Final Inspection: County inspection and completion report filing.

The entire process typically takes 2-5 days depending on depth increase and any complications encountered.

Southern California-Specific Considerations

Drought and Declining Water Tables

California's cyclic drought periods have caused water tables to drop in many areas:

• East County San Diego: Wells drilled in the 1970s-80s at 200-300 feet may now need to go 400-500 feet
• Riverside County: Agricultural pumping and population growth have lowered water tables 50-150 feet in some areas
• High Desert: Some areas experiencing significant declines, deepening by 100-200 feet increasingly common

SGMA and Groundwater Management

California's Sustainable Groundwater Management Act (SGMA) affects some basins:

• Some managed basins may restrict deepening in certain zones
• Reporting requirements for modified wells
• Check with your local groundwater sustainability agency before proceeding

Granite Formations in East County

Much of East San Diego County sits on granite bedrock:

• Water occurs in fractures, not porous zones
• May need to drill deeper to find productive fractures
• Drilling costs are higher ($100-$150/foot vs. $75-$100 in sedimentary rock)
• Success depends on finding fractures – no guarantee of improved yield

Alternatives to Well Deepening

Before committing to deepening, consider these alternatives:

• Well rehabilitation: Sometimes wells produce poorly due to mineral buildup or biofouling rather than depth. Professional cleaning and acidizing ($1,500-$4,000) can restore flow.
• Lower the pump: If your pump isn't at the bottom of the well, lowering it (assuming adequate static water level) costs just $800-$1,500.
• Drill a new well: In some cases, drilling a new well in a better location or with larger diameter makes more sense than deepening.
• Connect to public water: If available, may be comparable in cost to deepening and eliminates future well maintenance.

How to Get an Accurate Estimate

Well deepening isn't a one-size-fits-all project. We recommend:

1. Well inspection: We assess your current well's condition, review your well log, and measure static water level
2. Research nearby wells: Check well logs from neighboring properties to see what depths produce good yields
3. Discuss your needs: How much water do you need? Are you experiencing seasonal shortages or year-round problems?
4. Video inspection (optional): For older wells, $300-$500 video inspection can reveal casing condition and prevent surprises
5. Written estimate: We provide a detailed quote including deepening, new pump, and all associated costs

Get Your Well Deepening Evaluation

If your well is producing less water than it used to, don't wait until it runs dry. Contact Southern California Well Service at (760) 440-8520 for a professional evaluation. We'll assess whether deepening makes sense for your situation, provide accurate pricing, and help you make the best decision for your property.

Serving San Diego, Riverside, and San Bernardino counties with complete well deepening and rehabilitation services.