Prior Appropriation Explained: First in Time, First in Right (and Why Your Priority Date Is Money)

When a stream cannot supply everyone, rights are filled strictly in order of priority date, oldest first. The most senior rights take their full amount; junior rights take what is left, which in a bad year is nothing. A senior rightSenior rightA water right with an early priority date, served first in shortage. Senior rights are the premium asset in every western water market. holder can place a CallCall (river call)A senior right holder’s demand that upstream junior rights stop diverting until the senior right is satisfied. The mechanism that turns priority dates into real water. that curtails every right junior to it until the senior right is satisfied.

Seniority is the single largest driver of water right value: two rights for identical quantities on the same stream can differ in price by multiples purely on the date.

A water right is not ownership of molecules; it is the right to apply a quantity of water to a beneficial useBeneficial useThe legally recognized purpose (irrigation, municipal, industrial, instream flow) that both justifies and limits a water right. You hold what you beneficially use, not what the paper says.: irrigation, municipal supply, industry, and increasingly instream flowInstream flowWater legally protected to stay in a stream for fish, habitat, or water quality. Instream flow leasing pays owners to leave water in the river.. Beneficial use is both the basis and the measure of the right: you hold what you can beneficially use, not necessarily what the paper says.

In a lease or sale, this appears as the historic consumptive useHistoric consumptive use (HCU)The amount of water a right actually consumed over its history, which is generally the maximum that can be transferred or changed. Records of real use are worth money. analysis: what the right actually consumed historically is what can typically be transferred, which is why records of real use are worth money.

Most appropriation states have ForfeitureForfeiture (use it or lose it)The doctrine by which a water right unused for the statutory period, commonly five consecutive years, can be lost in whole or part. Approved leases and bank deposits protect against it. or AbandonmentAbandonmentLoss of a water right through sustained non-use combined with intent to relinquish it. Harder to prove than forfeiture, which needs no intent. doctrines: a right unused for the statutory period, commonly five consecutive years, can be lost in whole or part. The rules and grace mechanisms vary by state, and formal programs exist precisely to protect non-use: banks in Idaho, trust water in Washington, instream leases in Oregon.

Never let a right sit idle and unprotected: lease it, bank it, or file the protection your state offers, because an eroded right is value you cannot get back.

East of the 100th meridian, riparian doctrineRiparian rightsThe eastern-US doctrine tying water use to ownership of land along a stream. Several western states carry hybrid systems where old riparian claims coexist with appropriation permits. ties water use to land along the stream. Several western states, California, Texas, Kansas, Nebraska, Oklahoma, the Dakotas, Washington, and Oregon, carry hybrid histories where old riparian or pre-code claims coexist with the appropriation permit system that governs everything since.

For deal purposes the difference is mostly diligence: hybrid-state titles can carry both kinds of claims, and confirming which one you hold is step one of any lease or sale.