Arizona Water Well Statistics 2026: 48 Facts & Data You Need to Know
Arizona Water Well Overview
Arizona's groundwater resources are critical to the state's water supply, particularly given the arid climate and ongoing Colorado River allocation challenges. The Arizona Department of Water Resources (ADWR) manages one of the most comprehensive well registration systems in the western United States.
Source: Arizona Department of Water Resources Wells 55 Registry
Well Population by Type
| Well Type | Number of Wells | % of Total |
|---|---|---|
| Domestic/Exempt Wells | 142,500 | 63.3% |
| Agricultural/Irrigation | 45,000 | 20.0% |
| Municipal/Public Supply | 18,750 | 8.3% |
| Monitoring Wells | 11,250 | 5.0% |
| Industrial/Commercial | 7,500 | 3.4% |
Key Arizona Well Facts
- 1.5 million Arizonans rely on private wells for drinking water (USGS, 2024)
- 40% of Arizona's water supply comes from groundwater
- 2.5 million acre-feet of groundwater pumped annually
- 53 designated groundwater basins managed by ADWR
- 5 Active Management Areas (AMAs) with strict groundwater regulations
- 1,450+ monitoring wells tracked by ADWR for groundwater levels
- 4,800+ new well registrations filed in 2025
- Average well age: 28 years
- 312 licensed well drilling contractors in Arizona
Wells by Arizona County
Source: ADWR Wells Database, 2025
All 15 Arizona Counties by Well Count
| Rank | County | Total Wells | Avg Depth (ft) |
|---|---|---|---|
| 1 | Maricopa | 67,500 | 485 |
| 2 | Pima | 32,400 | 425 |
| 3 | Pinal | 24,750 | 520 |
| 4 | Yavapai | 18,900 | 395 |
| 5 | Cochise | 14,850 | 365 |
| 6 | Mohave | 13,500 | 445 |
| 7 | Yuma | 11,250 | 285 |
| 8 | Coconino | 10,350 | 680 |
| 9 | Navajo | 9,450 | 545 |
| 10 | Apache | 6,750 | 495 |
| 11 | Gila | 5,850 | 385 |
| 12 | Graham | 4,050 | 340 |
| 13 | La Paz | 2,700 | 265 |
| 14 | Santa Cruz | 1,800 | 245 |
| 15 | Greenlee | 900 | 320 |
Regional Highlights
Phoenix Metro Area (Maricopa County)
- Total wells: 67,500
- Primary aquifer: West Salt River Valley Basin
- Average depth: 485 feet
- Typical yield: 15-50 GPM (domestic), 500-2,000 GPM (irrigation)
- Water quality: Generally good; some areas have elevated TDS, arsenic
- Note: Located within Phoenix AMA with strict groundwater regulations
Tucson Area (Pima County)
- Total wells: 32,400
- Primary aquifer: Tucson Basin aquifer system
- Average depth: 425 feet
- Typical yield: 10-35 GPM (domestic)
- Water quality: Variable; some arsenic and hardness issues
- Note: Located within Tucson AMA; Central Arizona Project water available
Rural Areas (Outside AMAs)
- Exempt well limit: 35 GPM, up to 10 acre-feet/year
- Average depth: 350-550 feet
- Permit requirement: Registration only (no permit required)
- Growing areas: Yavapai, Cochise, Mohave counties seeing highest growth
Groundwater & Aquifer Statistics
Source: ADWR, USGS Arizona Water Science Center
Groundwater Use by Sector
| Sector | Annual Use (AF) | % of Total |
|---|---|---|
| Agricultural Irrigation | 1,850,000 | 74% |
| Municipal/Public Supply | 500,000 | 20% |
| Industrial | 150,000 | 6% |
Major Arizona Aquifers
| Aquifer System | Location | Storage (million AF) | Condition |
|---|---|---|---|
| Basin and Range (alluvial) | Central/Southern AZ | 850+ | Variable |
| Colorado Plateau | Northern AZ | 150+ | Stable |
| Coconino Aquifer | Flagstaff region | 45 | Good |
| Upper San Pedro Basin | SE Arizona | 12 | Declining |
| Santa Cruz Basin | Tucson area | 25 | Recovering |
Groundwater Level Trends
- Phoenix AMA: Water levels stable to rising due to recharge programs
- Tucson AMA: Recovering since CAP water delivery began (1990s)
- Pinal AMA: Declining 2-5 feet/year in agricultural areas
- Santa Cruz AMA: Generally stable with seasonal variation
- Prescott AMA: Declining 1-3 feet/year; conservation efforts ongoing
- Rural basins: Variable; some areas seeing significant declines
Active Management Areas (AMAs)
Arizona's five Active Management Areas contain about 80% of the state's population and have strict groundwater management requirements under the 1980 Groundwater Management Act.
| AMA | Population | Area (sq mi) | Annual GW Use (AF) | Goal |
|---|---|---|---|---|
| Phoenix | 4,900,000 | 5,646 | 850,000 | Safe Yield by 2025 |
| Tucson | 1,100,000 | 3,866 | 210,000 | Safe Yield by 2025 |
| Pinal | 450,000 | 4,792 | 1,200,000 | Preserve Ag Economy |
| Prescott | 250,000 | 485 | 25,000 | Safe Yield by 2025 |
| Santa Cruz | 55,000 | 716 | 18,000 | Safe Yield by 2025 |
AMA Regulations
- New wells in AMAs generally prohibited for irrigation use
- Exempt wells limited to 35 GPM and domestic use only
- Non-exempt wells require permit and groundwater right
- Well spacing requirements apply in most AMAs
- Metering required for non-exempt wells over 35 GPM
Well Depth Statistics
Source: ADWR Well Registry, 2025
Well Depths by Region
| Region | Residential Avg | Irrigation Avg | Typical Range |
|---|---|---|---|
| Phoenix Metro | 485 ft | 650 ft | 300-900 ft |
| Tucson Area | 425 ft | 580 ft | 250-750 ft |
| Prescott/Yavapai | 395 ft | N/A | 200-800 ft |
| Cochise County | 365 ft | 520 ft | 180-650 ft |
| Northern AZ (Coconino) | 680 ft | N/A | 400-1,200 ft |
| Yuma Area | 285 ft | 350 ft | 150-450 ft |
| Mohave County | 445 ft | 550 ft | 250-800 ft |
Depth Statistics
- Shallowest productive wells: Yuma area, along Colorado River (100-200 ft)
- Deepest domestic wells: Northern Arizona/Colorado Plateau (1,000-1,500 ft)
- Average depth increase: 35 feet over past decade (2015-2025)
- Wells over 500 feet: 28% of all new wells drilled in 2025
- Record depth: 2,100 feet (irrigation well, Pinal County)
Well Drilling Costs (2026)
Source: Arizona Well Drillers Association, industry surveys
Drilling Costs by Region
| Region | Low | Average | High |
|---|---|---|---|
| Phoenix Metro | $28,000 | $38,000 | $65,000 |
| Tucson Area | $24,000 | $34,000 | $55,000 |
| Prescott/Yavapai | $22,000 | $32,000 | $58,000 |
| Cochise County | $20,000 | $28,000 | $45,000 |
| Northern Arizona | $35,000 | $52,000 | $85,000 |
| Yuma Area | $18,000 | $25,000 | $38,000 |
| Mohave County | $26,000 | $36,000 | $60,000 |
Cost Breakdown
| Item | Cost Range |
|---|---|
| Drilling (per foot) | $25-75 |
| Casing (per foot) | $12-25 |
| Well Screen | $800-2,500 |
| Submersible Pump | $1,500-4,500 |
| Pressure Tank | $500-1,500 |
| Electrical/Controls | $1,200-3,500 |
| ADWR Registration | $150-350 |
| Water Testing | $150-400 |
Water Quality Statistics
Source: ADEQ, USGS NAWQA Program
Common Water Quality Issues
| Parameter | % Exceeding Standard | Affected Areas |
|---|---|---|
| Arsenic (>10 ppb) | 12% | Central/Southern Arizona |
| Fluoride (>4 mg/L) | 8% | Various locations |
| TDS (>500 mg/L) | 35% | Statewide |
| Hardness (>180 mg/L) | 55% | Most areas |
| Nitrate (>5 mg/L) | 6% | Agricultural areas |
| Uranium (>30 ppb) | 3% | Northern Arizona |
Treatment Recommendations
- Arsenic: Reverse osmosis or specialty media filtration
- Hard water: Water softener (ion exchange)
- High TDS: Reverse osmosis for drinking water
- Bacteria: Shock chlorination, UV treatment, or continuous chlorination
📊 Data Sources & Methodology
This statistics page compiles data from the following official sources:
- Arizona Department of Water Resources (ADWR) - Wells 55 Registry, groundwater data
- U.S. Geological Survey (USGS) - Arizona Water Science Center, NAWQA Program
- Arizona Department of Environmental Quality (ADEQ) - Water quality data
- Central Arizona Project - Water delivery and recharge data
- Arizona Well Drillers Association - Industry cost data
Data Collection Period: Statistics reflect data collected through January 2026.
Updates: This page is updated quarterly as new state data becomes available.
Frequently Asked Questions
How many water wells are in Arizona?
Arizona has approximately 225,000 registered water wells according to the Arizona Department of Water Resources (ADWR) Wells 55 Registry. This includes domestic, irrigation, municipal, and monitoring wells across all 15 counties. Maricopa County (Phoenix area) has the most wells with about 67,500.
What is the average well depth in Arizona?
The average residential well depth in Arizona is 400-500 feet, though depths vary significantly by region. The Phoenix metro area averages 485 feet, Tucson area 425 feet, and northern Arizona (Coconino County) often requires wells over 680 feet due to the deep Coconino Aquifer.
How much does it cost to drill a well in Arizona?
The average cost for a complete residential well system in Arizona in 2026 is $25,000-$45,000. Drilling costs range from $25-50 per foot for alluvial formations to $45-75 per foot for hard rock. Northern Arizona wells tend to be most expensive due to depth requirements.
Do you need a permit to drill a well in Arizona?
All wells in Arizona require registration with ADWR. Within Active Management Areas (AMAs), wells require permits. Outside AMAs, exempt wells (domestic use under 35 GPM) require only registration. All well drilling must be performed by a licensed driller registered with ADWR.
What are Arizona's main aquifers?
Arizona has 53 designated groundwater basins. Major aquifers include the Basin and Range alluvial aquifers (supplying Phoenix and Tucson), the Colorado Plateau aquifers, and the Coconino Aquifer in northern Arizona. These aquifers provide about 40% of Arizona's total water supply.
How much groundwater does Arizona use annually?
Arizona uses approximately 2.5 million acre-feet of groundwater annually, representing about 40% of the state's total water use. Agricultural irrigation accounts for 74% of groundwater withdrawals, followed by municipal use (20%) and industrial use (6%).
Need Well Service Information?
While Southern California Well Service primarily serves San Diego and Riverside Counties in California, we're happy to provide guidance and referrals for Arizona well owners.
For California service: (760) 463-0493
Or contact us online for more information.