Water for an off-grid home in Arizona
Before relying on a well, spring, shared line, cistern, or rain tank, prove five different things: legal authority, physical availability, acceptable quality, approval for the home, and year-round reliability.
May this person use this source for this purpose?
Is enough water physically present at a viable cost?
Is it safe and suitable, with realistic treatment?
Will the home’s permitting authority accept the system?
Will it work through drought, outages, winter, and access problems?
Start with the source
Six paths. Six different investigations.
Do not let a listing’s word—“well,” “water available,” “shared,” “haul,” “spring”—stand in for documents, tests, rights, and approval.
Private well
ADWR records and filing, basin rules, physical well condition, yield, quality, power, storage, and setbacks.
State pathway · site outcomeShared well
Everything for a private well, plus a durable agreement, easements, capacity, allocation, operating history, and remedies.
Private contract riskCommunity provider
Service-area status does not equal a commitment. Obtain availability, capacity, connection fees, line-extension terms, and ongoing charges.
Provider confirmationHauled water
Approved source, delivery access, cistern construction, potable treatment, inspection, fire reserve, operating cost, and local acceptance.
Local approval requiredRainwater
Collection area, rainfall variability, storage, treatment, overflow, mosquito protection, end use, and whether it can support the permitted residence.
Do not size from annual average aloneSurface water or spring
Legal classification, water right, point of diversion, beneficial use, adjudication, physical flow, quality, storage, and seasonal reliability.
Ownership is not the water rightPrivate wells
Read the record. Then investigate the well that is actually there.
A Notice of Intent must be filed with the Arizona Department of Water Resources before drilling, and the work must be performed by a licensed well drilling contractor.
Use ADWR’s Wells55 search and imaged records. Parcel changes and older owner names can complicate the search.
Confirm location, registration number, construction, depth, casing, pump, power, storage, and ownership on site.
Obtain a current professional yield and recovery evaluation appropriate to the well and anticipated demand.
Use a certified laboratory and a location-appropriate panel. Budget treatment and ongoing testing.
Identify the basin, AMA or INA, well classification, proposed use, filings, rights, setbacks, and local site approval.
Arizona’s groundwater map is not static.
Because Active Management Areas carry additional groundwater regulation, and Arizona's AMA map changed recently with subsequent designations including Douglas, Willcox, and Ranegras Plain.
Groundwater use in Arizona; the controlling requirements depend on the parcel's current basin, sub-basin, AMA or INA status, well type, capacity, and intended use.
Active Management AreaAdditional groundwater management applies. Well capacity, use, rights, reporting, and siting can matter.
Irrigation Non-expansion AreaIrrigation and non-exempt-well measurement or reporting rules require separate review.
Outside an AMA or INAThat does not mean “unregulated.” Well filing, construction, setbacks, surface-water law, and local approval remain.
ADWR’s 2026 overview lists eight AMAs, including the more recent Douglas, Willcox, and Ranegras Plain designations. Use the current agency map when evaluating a parcel.
Open ADWR AMA overviewShared wells
The pipe may be physical. Your right is contractual.
No. ADWR says shared-well agreements are civil matters between the private parties and are not regulated or enforced by ADWR or another state agency.
- Who owns the well and the land beneath it?
- Which parcels and users have enforceable rights?
- How much water may each party use?
- Who pays electricity, testing, maintenance, repair, and replacement?
- Who may enter the well parcel, and through which easement?
- What happens during shortage, contamination, sale, default, or dispute?
Retrieve the well file and recorded shared-well documents, confirm the operating history with all parties, and make satisfactory legal and physical review a purchase contingency.
Surface water and springs
Property ownership and water rights are different evidence.
No. Arizona treats surface water as public and subject to appropriation; a new use generally requires the applicable permit and certificate from ADWR.
- A right to use surface water is not created simply by owning adjacent land.
- The Public Water Code uses prior appropriation and beneficial use principles.
- Existing rights, adjudications and the legal classification of the source can affect availability.
Water quality
Registered does not mean potable.
No. ADEQ does not regulate private wells as public water systems and strongly encourages owners to test periodically for bacteria and other contaminants.
Build the test around the place.
A basic bacteria result is not a universal clearance. Nearby land uses, known contamination sites, local geology, well construction, and intended household use should shape the sampling plan.
“100-year supply” is not a home inspection for water.
No. The programs evaluate water supply for regulated subdivision and provider contexts; a buyer still needs parcel- and source-specific evidence.
Subdivision and provider water-supply determinations administered by ADWR. Assured Water Supply applies within AMAs; Adequate Water Supply operates outside AMAs, with mandatory and non-mandatory local variations.
ADWR program overviewBefore you buy
The Arizona water evidence file
Keep the documents, not merely the conclusion. If one item is unavailable, label it as an unresolved purchase risk.
- 01Location and authority
Parcel, basin, sub-basin, AMA or INA, provider service area, and responsible local authority.
- 02Legal source record
Well registration and file, water right or permit, service commitment, or recorded shared-well agreement and easements.
- 03Physical performance
Current yield and recovery evidence, condition assessment, seasonal history, storage, pumping equipment, and backup plan.
- 04Quality evidence
Current laboratory results, appropriate contaminant panel, treatment design, operating cost, and waste handling.
- 05Residential approval
Written confirmation that the proposed source, storage, treatment, and plumbing satisfy the permit and occupancy pathway.
- 06Long-term budget
Connection or drilling, pump, power, delivery, testing, treatment, maintenance, replacement, drought, and emergency supply.