How Deep Should a Well Be?

The Basics

What the Driller Is Looking For

• Water-bearing formation (aquifer)
• Adequate flow rate (GPM)
• Sustainable water source
• Good water quality

Depth Ranges

National Averages

• Average residential well: 100-400 feet
• Some areas: as shallow as 25-50 feet
• Other areas: 1,000+ feet required

What Determines Depth

Geology

• Alluvial valleys: Often shallow water
• Fractured rock: Water in fractures at various depths
• Granite: Need to find fracture zones
• Sedimentary: May have multiple aquifers

Water Table

• Static water level varies by location
• May be 50 feet in one area, 500 in another
• Fluctuates seasonally
• Has been dropping in many areas

Neighbor Wells

• Good indicator of expected depth
• Well logs on file with county
• Ask neighbors about their wells
• Not a guarantee—geology varies

Topography

• Hilltops usually deeper
• Valleys often shallower
• Near streams/rivers: shallower

Usage Needs

• Higher demand may need deeper well
• Or multiple water zones
• Agricultural: often deeper for more capacity

Typical Depths by Area

San Diego County

Riverside County (Anza/Temecula)

• Anza Valley: 200-400 feet
• Mountain areas: 400-800 feet
• Temecula Valley: 200-500 feet

Factors That Vary Locally

• Specific geology of your parcel
• Distance from nearest producing well
• Whether you're in a known aquifer
• Historical water levels

Is Deeper Better?

Not Necessarily

• Deeper = higher drilling cost
• Deeper = more expensive pump installation
• Some formations have less water at depth
• Deeper water may have more minerals

Advantages of Deeper Wells

• Often more reliable long-term
• Better protected from surface contamination
• May have better water quality
• Less affected by drought

Shallow Well Advantages

• Lower drilling cost
• Less expensive pump
• Lower operating cost (less lift)
• May have excellent flow in right geology

The Goal

Reach a reliable aquifer with adequate yield. If that's at 200 feet, no need to drill to 400. If water isn't reached until 500 feet, that's what's needed.

Trust Your Driller

• Experience in your area matters
• They've seen the geology firsthand
• They want a successful well too
• Ask about their recommendation

We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.

Frequently Asked Questions

How deep should my well be?

Depends on local geology. San Diego County: typically 300-600 feet. Your driller can estimate based on area well logs and geology.

Is a deeper well better?

Not automatically. Deeper costs more and isn't always necessary. Goal is reaching a good aquifer—not maximum depth.

Can I find out how deep neighbors' wells are?

Yes—well logs are public record, available from the county or state. Drillers also know typical depths in your area.

What if the well doesn't hit water at expected depth?

Driller will continue deeper. Discuss "dry hole" policies before drilling. Some areas are just deeper than expected.

Does depth affect water quality?

Can, yes. Deeper water is better protected from surface contamination. But may have more dissolved minerals. Test regardless of depth.