Why the boundaries are the hard part

Every record behind an Arizona report is public. That is not the moat and it was never going to be. What is genuinely hard is that the answer to "what governs the water under this land" is spread across agencies that do not share an identifier, and that in Arizona the answer is decided almost entirely by boundaries: which management area, which basin, which service area, which subdivision, none of which are visible from the road or written in a listing.

The cadastral grid is the join

The Department of Water Resources publishes a cadastral grid of nine and a half million cells, and almost every record it keeps is registered against a cell rather than against a coordinate. That grid is the keystone: it is what turns a well, a water level measurement, a filing and a parcel into things that can be asked about the same piece of ground.

Building it was not a download. The published endpoints in the obvious places were dead, the department had reorganised, and the working services had to be found individually. That is the ordinary condition of this work rather than an unlucky week.

A boundary that runs through a section

Because Arizona answers are boundary answers, the boundary cases matter more than they would elsewhere. A section that straddles a management area edge has two different regulatory answers inside one square mile, and reporting either one as the answer would be confidently wrong for half the ground. Those are detected and said out loud, rather than resolved by whichever polygon the centroid happened to land in.

The traps in the well registry

• An absent depth or yield arrives as a zero in several extracts. Nulled, never averaged in, never clamped.
• A fifth of registrations are cancelled or superseded. Counted separately from live wells, always.
• Monitoring and observation holes are filed beside production wells. Named as such.
• The water-use column arrives as several uses concatenated into one string, and splitting it wrongly turns a stock well into a domestic one.

Each of those is there because it was got wrong once, found, and fixed, and each has a test that fails if it comes back. A guard that matches nothing passes for the wrong reason, so each one also asserts it scanned something.

Everything is dated

Every source carries when it was last loaded and how far behind the publisher it is. Some of these move on a decade timescale and some land weekly. A report that presents both with the same confidence is lying by omission, so it prints the age of what it read.

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.