Hydrohistorian

Look up any ditch, well, reservoir or gage in Colorado. See what it’s doing today, what a century of records says about it, and where its water fits in the law.

New to water rights? Start here: what is paper water?

Every structure, gage, district and water utility in Colorado — 177,603 of them. Or browse the map below.

199,676 structures and 2,529 gages across 78 water districts · clicktap a district to open it

Know it by name? Browns Canyon The Numbers Bighorn Sheep Canyon Clear Creek Canyon Poudre Canyon Eagle River Roaring Fork Blue River
Or browse by type: Gages Ditches Reservoirs Wells Springs

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What you get on a district page

Per basin
A longitudinal flow schematic, a date picker to reconstruct any historical day, trend & changepoint statistics per gage, and a legal view: seniorityColorado shares water by date: the earlier the right, the stronger its claim when the river runs short. "First in time, first in right.", compliance screens, and callA senior water right demanding its water, which requires everyone junior on that stream to stop diverting until it is satisfied.-based stoppage explanations with links to court records.
My Water
Save your own WDIDs and each visit reports what changed for them: an active call senior to your rights, a new court case, a revision to your published record. Free account.
Who serves your tap
Type an address above and the pin names the water utility whose service area holds it, or turn on the map's Providers chip. Every public water system in Colorado with its source, who it buys from, its violations and its PFAS results.
Groundwater
34,000 monitored wells and over a million water-level measurements back to 1883, with per-well trends, stream-corridor water-table histories, and each aquiferA body of rock or sediment that holds usable groundwater; a well's aquifer says which of those layers it draws from. unit as its own head surface. Advisory — never a substitute for DWR administration.

Built from Colorado DWR's own records — HydroBaseDWR's own master database of Colorado water records -- rights, structures, measurements -- which this site mirrors and reads. plus live REST, cross-checked against USGS. How this site is built, and what it cannot tell you →