What a right actually yields

The ceiling in court

Colorado permits changing a right’s use, place or timing — but never expanding it. The measure of what may transfer is the right’s historical consumptive use: what it actually, beneficially consumed over a representative period. Diverted is not consumed — the unconsumed share went back as return flows that neighbors now depend on, so an HCU analysis credits only consumption, and the return-flow pattern must be maintained. This is the most litigated number in Colorado water because the entire price of a transaction rides on it.

The sentence that matters, then, has this shape: “This 3.5 cfs 1889 right diverted a median 412 AF/yr over the last two decades, was in priority 71% of the irrigation season, and its use trend is flat.” — observed behavior, not decreed possibility.

See it on a real structure

Pick a structure and see its observed behavior, screen-level.

Or start with a worked example: Farmers Highline Canal, Agricultural Ditch.

What this does not let you conclude

These are diversion-based screens: a real HCU analysis subtracts return flows, chooses a representative period defensibly, handles enlargement and non-use questions, and survives opposing counsel — engineering work this page points at and does not do. Advisory reading aid on public data — never an administrative or legal conclusion, and never a substitute for DWR administration or an engineer’s analysis. Our methodology has not yet had outside expert review: how this is built.