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Lesson A2 · prior appropriation

Paper water and wet water

A right's decreed amount is not the water it gets. The most consequential misunderstanding in Colorado water.

A water right names an amount — so it is natural to assume that amount is the water the ditch gets. It is not. The decree states the most a right may divert when water is available and the right is in priorityA senior water right demanding its water, which requires everyone junior on that stream to stop diverting until it is satisfied.; what a structure actually diverted, year by year, is a different and usually much smaller number. The gap between them has a name in Colorado water circles: paper water versus wet water.

The paper the most the decree allows The water a typical year the gap = paper water water the right could take, but the river never had — or the call took
A right names the most a structure may divert; what it actually diverts in a typical year is a fraction of that. The bar the decree writes and the bar the river fills are rarely the same length — and the difference between them is what “paper water” means.

See it on a real structure

Any ditch, canal or pump in the state — try your own. The numbers below come from DWR's decree and diversion records.

ENTRIKIN DITCH on NORTH FORK SOUTH PLATTE

The paper: its 1 absolute decreed right total 1.0 cfsCubic feet per second, a rate of flow. One cfs running for a day is about 2 acre-feet.. Flowing all 183 days of an April–October season, that rate would move 363 AFA volume: one acre covered a foot deep, about 326,000 gallons -- roughly a suburban household's outdoor use for a year..

The water: in its median recorded year it actually diverted 2 AF — 1% of the paper figure.

Every recorded year against the same bar
1978
2 AF · 80% of median
1979
3 AF · 120% of median

A bar outlined in green exceeded the seasonal screen — winter diversions and storage movements can lawfully do that, which is itself a lesson in reading records.

The full record behind these figures: ENTRIKIN DITCH’s dossier.

Why the gap exists

Three reasons, all structural. The decree states a maximum rate, not a running total — a headgate rarely runs full for a whole season. The right can only divert when it is in priority — in a dry year a junior right may be called outNot entitled to divert right now, because a senior right is calling for the water. for much of the season. And a farm only takes what its crops and its ditch capacity can use.

The gap matters because Colorado law knows it. When a right is sold or its use is changed, the measure of what transfers is not the decreed amount but the right’s historical consumptive use — what was actually, beneficially consumed. Buying the paper number and receiving the wet one is the classic expensive mistake in Colorado water, and the reason change cases are fought over diversion records like the ones on this page.

What this does not let you conclude

The seasonal figure is a screen — the decreed rate run for a 183-day season — not an entitlement or a forecast, and diversions are not consumptive use: a real HCU analysis subtracts return flows and is engineering work this page does not do. Records can be incomplete, and a low year may reflect administration, drought, or simply a farmer’s choice. Advisory reading aid on public data — never a valuation, a title opinion, or a substitute for DWR administration.

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