Arizona articles · Wells
What a well registration does not tell you
Arizona’s well registry is deep, public, and full of rows that do not mean what they appear to.
Arizona keeps a registry of wells, and it is one of the better public records in the country: hundreds of thousands of rows carrying location, depth, casing, pump capacity, intended use and the driller’s log. It is also read wrongly more often than any other source we handle, because several of its columns look like measurements and are not.
A count of registrations is not a count of wells. Cancelled registrations and monitoring holes are filed in the same table as the well somebody drinks from.
ADWR well registry · computed September 2026
A fifth of the registry is cancelled or superseded, and another large block is monitoring and observation holes, drilled to watch an aquifer rather than to take water from it. Counting rows and calling the result "wells nearby" overstates the neighbourhood by a wide margin, and it is the first thing a naive read gets wrong.
The exempt well
A well pumping no more than thirty-five gallons a minute for non-irrigation use sits in a lighter category, which is how a single household on rural land gets water without a withdrawal permit.
A well with a pump capacity of not more than thirty-five gallons per minute, withdrawing groundwater for non-irrigation use, is an exempt well and is not subject to the withdrawal permit requirements that apply to other wells.
A.R.S. 45-454
The category is defined by pump capacity and by use, not by how much is actually taken, and it is narrower than the phrase "exempt well" suggests. It does not authorise irrigating a field, and inside a management area the surrounding rules still apply to the land even where they do not apply to the pump.
Zero is not a measurement
Sixty-two thousand registrations carry no drilled depth at all. Treating an absent depth as a zero is the single most common way this table is read wrongly, and it drags every average toward the surface.
ADWR well registry · computed September 2026
Tens of thousands of registrations carry no drilled depth at all, and in several of the published extracts an absent value arrives as a zero rather than as a blank. Averaging those in produces a figure that is wrong by hundreds of feet and looks entirely reasonable on a page. Every one of them is nulled here, never clamped and never counted, and the report says how many wells the distribution is actually built from.
The same applies to the use column, which arrives as several uses concatenated into one string. Split it wrongly and a stock well becomes a domestic one.
wells
Live production wells carrying a depth, with cancelled registrations and monitoring holes removed. The median is 260 feet.
ADWR well registry · computed September 2026
Read carefully, with cancelled registrations removed, monitoring holes removed and absent depths excluded rather than zeroed, the neighbouring registrations answer the question the listing never does: how deep drillers have had to go around here, and what they found when they got there.
What the report does with this
- Registered wells on the section, with use, casing depth and pump capacity where the record carries them
- Depths and yields nearby as a distribution, with unrecorded values excluded rather than counted as zero
- Cancelled, superseded and never-drilled registrations kept apart from live ones
- Monitoring and observation holes named as such rather than counted as supply
- Whether the parcel sits where an exempt well is the ordinary answer or where it is not
This is general information about Arizona law and records. It is not legal advice and not a title opinion. What applies to a particular piece of ground is settled by the documents filed against it.