By SCWS Team
February 1, 2026 · 15 min read
When the summer sun beats down on a 20-acre avocado grove, there's no room for uncertainty about water. Every drop counts—and every dollar spent on municipal water cuts directly into your bottom line. That's why generations of Southern California farmers, from Fallbrook's rolling hillsides to Temecula's acclaimed vineyards, have turned to a proven solution: drilling their own agricultural wells.
With water rates climbing past $1,000 per acre-foot and drought restrictions growing tighter each year, the math has never been clearer. A properly designed agricultural well can pay for itself in just 2-3 growing seasons—while giving you complete control over your most critical resource. This comprehensive guide covers everything you need to know about farm well drilling, from costs and water requirements to pump systems and permits.
Quick Overview: Agricultural wells cost $40,000-$100,000+ and produce 50-500+ gallons per minute (GPM)—far more than residential wells. The investment typically pays for itself within 3-7 years through water cost savings and protects your farming operation from drought restrictions.
Agricultural vs. Residential Wells: Key Differences
If you're familiar with residential water wells, agricultural wells operate on an entirely different scale. Understanding these differences is crucial for proper planning and budgeting.
| Specification | Residential Well | Agricultural Well |
|---|---|---|
| Casing Diameter | 6 inches | 8-16 inches |
| Flow Rate | 5-15 GPM | 50-500+ GPM |
| Pump Horsepower | 1-3 HP | 25-100+ HP |
| Daily Usage | 300-500 gallons | 10,000-100,000+ gallons |
| Typical Depth | 300-500 feet | 400-800+ feet |
| Total Cost | $20,000-$40,000 | $40,000-$100,000+ |
| Permit Complexity | Standard | Enhanced review required |
Why the Differences Matter
The larger diameter of agricultural wells isn't just about pumping more water—it's about sustained production capacity. A 6-inch residential well can't physically accommodate the pump equipment needed for high-volume irrigation. Similarly, the aquifer needs adequate recharge area around the well screen to supply water at agricultural rates without causing drawdown problems.
Learn more about well depth requirements by location to understand what your property might need.
Water Requirements by Crop Type
Southern California's diverse agriculture means water requirements vary dramatically by crop. Properly sizing your agricultural well requires understanding your specific irrigation needs.
Avocado Orchards
San Diego and Riverside counties are California's avocado heartland. These thirsty trees have specific water needs:
- Annual water requirement: 40-60 inches (3-4 acre-feet per acre)
- Peak summer demand: 1.5-2 inches per week
- Well capacity needed: 15-25 GPM per acre during peak season
- Irrigation method: Micro-sprinklers or drip systems preferred
- Critical periods: Fruit set (spring) and sizing (summer)
Example: A 10-acre avocado grove in Fallbrook needs approximately 30-40 acre-feet of water annually. During July and August, peak demand may reach 200,000+ gallons per week. A well producing 100-150 GPM can meet this demand with 12-16 hours of daily pumping.
Citrus Groves (Oranges, Lemons, Grapefruit)
Citrus trees are slightly less water-intensive than avocados but still require substantial irrigation:
- Annual water requirement: 36-48 inches (3-4 acre-feet per acre)
- Peak summer demand: 1-1.5 inches per week
- Well capacity needed: 12-20 GPM per acre
- Irrigation method: Drip, micro-sprinklers, or flood irrigation
- Drought tolerance: Moderate—can reduce irrigation temporarily
Wine Grapes (Vineyards)
Temecula Valley's wine industry benefits from grapes' relatively efficient water use:
- Annual water requirement: 12-24 inches (1-2 acre-feet per acre)
- Peak summer demand: 0.5-1 inch per week
- Well capacity needed: 8-15 GPM per acre
- Irrigation method: Drip irrigation (most efficient)
- Deficit irrigation: Often practiced to improve grape quality
Vineyard Advantage: A 30-acre Temecula vineyard using drip irrigation may only need a well producing 75-100 GPM—significantly less than an equivalent citrus or avocado operation. This often allows for smaller, less expensive well systems.
Row Crops and Vegetables
Seasonal vegetable operations have different patterns than permanent crops:
- Annual water requirement: Varies widely (18-36 inches depending on crop)
- Irrigation method: Drip, furrow, or overhead sprinklers
- Well capacity needed: 15-25 GPM per acre for overhead irrigation
- Seasonal use: May not pump year-round
High-Capacity Pump Systems for Agriculture
Agricultural wells require industrial-grade pump systems engineered for continuous, high-volume operation. The pump system often represents 30-40% of total project cost.
Submersible Turbine Pumps
The most common choice for agricultural wells, submersible turbine pumps offer:
- Capacity: 50-1,000+ GPM depending on model
- Motor size: 25-200 HP
- Efficiency: 70-85% at optimal operating point
- Lifespan: 10-20 years with proper maintenance
- Cost: $15,000-$50,000+ installed
Line Shaft Turbine Pumps
For very high capacity or deep wells, line shaft turbines provide:
- Capacity: 100-2,000+ GPM
- Motor location: Surface-mounted (easier maintenance)
- Best for: Depths under 500 feet, very high flow rates
- Cost: $20,000-$75,000+ installed
Variable Frequency Drives (VFDs)
Modern agricultural well systems increasingly use VFDs to optimize efficiency:
- Energy savings: 20-50% reduction in electricity costs
- Soft start: Reduces mechanical stress on pump and motor
- Pressure control: Maintains consistent irrigation pressure
- Cost: $3,000-$15,000 depending on motor size
- ROI: Typically pays for itself within 2-4 years
Learn about different types of well pumps and which might be best for your operation.
💡 Pro Tip: Variable Frequency Drives
Installing a VFD on your agricultural pump can cut electricity costs by 20-50% and dramatically extend pump life. The soft-start feature alone often pays for the VFD within the first year by reducing mechanical stress on startup.
Flow Rate Requirements: Sizing Your Agricultural Well
Undersizing your well is a costly mistake. Here's how to calculate the flow rate your farm needs:
Basic Flow Rate Calculation
Formula:
Required GPM = (Acres × Water per acre per day in gallons) ÷ Pumping hours per day
Example: 20-acre avocado grove needing 1.5 inches/week (0.21 inches/day)
Daily water = 20 acres × 27,154 gal/acre-inch × 0.21 inches = 114,000 gallons
If pumping 12 hours/day: 114,000 ÷ 720 minutes = 158 GPM required
Recommended Flow Rates by Application
| Farm Size | Crop Type | Recommended GPM |
|---|---|---|
| 5-10 acres | Avocados/Citrus | 75-150 GPM |
| 10-25 acres | Avocados/Citrus | 150-300 GPM |
| 25-50 acres | Avocados/Citrus | 300-500 GPM |
| 10-30 acres | Vineyard (drip) | 75-150 GPM |
| 20-50 acres | Row crops | 200-400 GPM |
Storage Tanks: An Alternative to Oversizing
If your aquifer can't sustain the peak flow rates you need, storage tanks provide an alternative:
- Strategy: Pump continuously at lower rates into storage, then irrigate from tank
- Tank sizes: 10,000-100,000+ gallon agricultural tanks available
- Cost: $1-3 per gallon capacity installed
- Benefits: Smaller pump, reduced well stress, backup water supply
Permit Considerations for Agricultural Wells
Agricultural well permitting in California has become more complex due to groundwater management regulations. Here's what you need to know:
⚠️ Know Before You Drill
Under California's SGMA regulations, some groundwater basins now have moratoriums on new wells or strict allocation limits. Always verify your property's groundwater basin status before investing in a well project to avoid permit denials.
County Well Permits
All wells require permits from your county's environmental health or water resources department:
- San Diego County: Department of Environmental Health ($500-$1,200)
- Riverside County: Department of Environmental Health ($400-$1,000)
- Processing time: 2-8 weeks typical
- Requirements: Site plan, setback verification, well design specifications
Read our detailed guide on well permits in San Diego County.
SGMA (Sustainable Groundwater Management Act)
California's SGMA affects agricultural wells in designated groundwater basins:
- Basin sustainability plans: May limit new well permits in overdrafted basins
- Metering requirements: Many basins require production meters on ag wells
- Reporting: Annual water use reporting may be mandatory
- Allocation limits: Some basins cap water extraction per acre
- Fees: Extraction fees in some managed basins
Environmental Review (CEQA)
Large agricultural well projects may trigger California Environmental Quality Act review:
- When required: New wells in sensitive areas, very high capacity wells
- Exemptions: Many agricultural wells qualify for categorical exemptions
- Timeline: Can add 2-6 months to permitting
- Costs: $5,000-$25,000+ for environmental studies if required
Water Rights Considerations
In California, groundwater rights are generally tied to overlying land ownership, but consider:
- Overlying rights: Landowners can pump for reasonable beneficial use
- Adjudicated basins: Some basins have court-determined water rights
- Prior appropriation: May affect new wells in water-scarce areas
- Legal consultation: Recommended for large irrigation projects
Agricultural Well Cost Breakdown
Understanding where your money goes helps you budget accurately and evaluate quotes. Here's a detailed cost breakdown for typical agricultural well projects:
Typical Agricultural Well Costs (2026)
Small Farm Well (50-100 GPM)
- • Drilling (500 ft @ $65/ft, 8" casing): $32,500
- • Pump & motor (25-40 HP submersible): $12,000-$18,000
- • Electrical (panel, wiring, controls): $5,000-$8,000
- • Permits & testing: $1,500-$3,000
- Total: $40,000-$60,000
Medium Farm Well (100-250 GPM)
- • Drilling (600 ft @ $75/ft, 10-12" casing): $45,000
- • Pump & motor (50-75 HP turbine): $20,000-$30,000
- • VFD and controls: $8,000-$12,000
- • Electrical service upgrade: $5,000-$15,000
- • Permits & testing: $2,000-$4,000
- Total: $65,000-$90,000
Large Commercial Well (250-500+ GPM)
- • Drilling (700 ft @ $85/ft, 12-16" casing): $59,500
- • Pump & motor (100+ HP line shaft turbine): $35,000-$50,000
- • VFD, controls, SCADA monitoring: $15,000-$25,000
- • Electrical (3-phase service, transformers): $15,000-$30,000
- • Storage tank (if needed): $20,000-$50,000
- • Permits, engineering, environmental: $5,000-$15,000
- Total: $100,000-$175,000+
Compare these costs with residential well drilling costs to understand the scale difference.
ROI: When Does an Agricultural Well Pay for Itself?
The financial case for agricultural wells is compelling when you compare costs to municipal water rates:
Municipal Water Cost Comparison
Typical agricultural water rates in Southern California:
$800-$1,500 per acre-foot (municipal/district water)
20-acre avocado grove example:
Annual water need: 60-80 acre-feet
Municipal cost: $48,000-$120,000 per year
Well operating cost (electricity): $8,000-$15,000 per year
Annual savings: $40,000-$100,000+
At these savings rates, a $75,000 agricultural well can pay for itself in 1-3 years. Even with financing costs, the investment typically breaks even within 5 years.
☀️ Solar-Powered Irrigation
Many agricultural operations pair their well with a solar array. With net metering, you can run your irrigation pump during sunny days (when crops need water most) at near-zero cost. Some farms achieve complete energy independence for their water needs.
Additional Benefits Beyond Cost Savings
- Drought protection: No mandatory cutbacks during water emergencies
- Crop quality: Irrigate on your schedule, not rationing schedules
- Property value: Producing ag well adds significant value to farm property
- Expansion capability: Water capacity to grow your operation
- Energy independence: Pair with solar for near-zero water costs
The Agricultural Well Drilling Process
Commercial well drilling follows a systematic process to ensure optimal results:
1. Site Assessment and Planning (2-4 weeks)
- Geological survey and well log research
- Water requirement analysis based on crop plans
- Site selection (access, setbacks, aquifer location)
- Pump system engineering
- Project cost estimate
2. Permitting (2-8 weeks)
- County well permit application
- SGMA compliance verification (if applicable)
- Environmental review (if required)
- Electrical permit for pump installation
3. Drilling (1-3 weeks)
- Equipment mobilization
- Drilling to target depth (typically 50-100 feet per day)
- Casing and screen installation
- Gravel pack placement
- Well development (surging and cleaning)
- Yield testing
4. Pump Installation (1-2 weeks)
- Pump and motor installation
- Electrical connections
- VFD programming (if applicable)
- Control system setup
- Performance testing
5. Final Steps
- Water quality testing
- Well completion report filing
- Connection to irrigation system
- Operator training
Total timeline: 6-16 weeks from initial consultation to operational well.
Maintaining Your Agricultural Well
Agricultural wells work harder than residential wells and require proactive maintenance:
- Annual inspections: Check pump efficiency, water levels, and water quality
- Pump servicing: Every 3-5 years for submersibles, annually for line shafts
- Well rehabilitation: Every 10-15 years to restore yield
- Monitoring: Track production rates to catch problems early
Read our complete well maintenance guide for detailed recommendations.
Frequently Asked Questions
How much does an agricultural well cost in Southern California?
Agricultural wells in Southern California typically cost between $40,000 and $100,000 or more, depending on depth, diameter, and required flow rate. Small farm wells (10-50 GPM) start around $40,000-$60,000, while high-capacity irrigation wells producing 100+ GPM can exceed $100,000 with industrial pump systems.
What is the difference between residential and agricultural wells?
Agricultural wells differ from residential wells in several key ways: larger casing diameter (8-16 inches vs 6 inches), higher flow rates (50-500+ GPM vs 5-15 GPM), more powerful pump systems (25-100+ HP vs 1-3 HP), deeper drilling in many cases, and more complex permitting requirements. Agricultural wells are engineered for sustained high-volume water production.
How much water does an avocado farm need per acre?
Mature avocado trees in Southern California require approximately 40-60 inches of water annually, translating to roughly 3-4 acre-feet per acre per year. During peak summer months, a 10-acre avocado grove may need 15-25 GPM of continuous irrigation capacity. Proper well sizing ensures adequate water even during drought conditions.
Do I need a special permit for an agricultural well in California?
Yes, agricultural wells in California require permits from your county's environmental health or water authority. Requirements vary by county and may include: well construction permits, environmental review (CEQA), water rights verification, setback compliance, and in some groundwater basins, allocation limits or reporting requirements under SGMA (Sustainable Groundwater Management Act).
What flow rate do I need for irrigation wells?
Required flow rate depends on acreage and crop type. General guidelines: 15-25 GPM per irrigated acre for row crops, 20-30 GPM per acre for citrus/avocados, and 10-15 GPM per acre for vineyards with drip irrigation. A 20-acre citrus grove typically needs a well producing 150-200+ GPM to meet peak summer demand without storage.
Ready to Discuss Your Agricultural Well Project?
Every farm is different. Whether you're irrigating 5 acres of avocados or 50 acres of citrus, we'll engineer a well system matched to your specific needs. Our team has drilled hundreds of agricultural wells throughout San Diego and Riverside counties. Visit our well drilling services page to learn more, then contact us for a comprehensive site assessment and detailed proposal.