Hydrohistorian
Everything on this site
One page, every door, grouped by what you are doing. The header holds
seven; the site holds more than that, and this is where the rest live.
Rivers, right now
What is flowing, what is calling, and how this year sits in the record.
- The mapEvery district, with what is calling and flowing now; click any dot.
- GagesEvery stream gage by district, with its record and live flow.
- SnowpackThis water year on the ground, district by district.
- Runoff outlookThe site's own seasonal forecast beside NRCS, with its receipts.
- Forecast report cardFifty years of NRCS forecasts graded against what the rivers delivered.
- DroughtEvery river against its own record, with the Drought Monitor beside it.
- Long-term trendsWhere flow is changing, ranked, with the statistics shown.
- The water itselfUSGS sensors reporting temperature, conductance, oxygen and turbidity right now, by district.
- Water providersEvery public water system: source, counties, water district, and who it buys from or sells to.
Water rights and administration
Who holds what, who is in priority, and what the courts are being asked.
- DitchesEvery decreed ditch by district; each has a dossier.
- ReservoirsEvery decreed reservoir by district, with storage where DWR reports it.
- SpringsDecreed springs by district.
- Decreed wellsWells with a decree, by district -- distinct from the permit file.
- Transbasin diversionsThe tunnels and ditches that carry water across the Divide, and their operators.
- Interstate compactsThe nine agreements above every Colorado water right, with their gages.
- Instream flow rightsEvery reach and natural lake level the CWCB holds a right for, with its seasonal schedule.
- The water courtsThis month's resume in each division with the objection deadline, active SWSPs, and where the decrees live.
- Paper water and wet waterThe lesson most readers arrive at from search.
Groundwater
Three records that used to be reachable only sideways.
- GroundwaterThe door: what is under a spot, the permit file, the monitoring network.
- Monitoring wellsDWR's water-level network, district by district.
- Well permitsEvery permit filed, statewide, by division and district.
- The Driller's AtlasWhat drillers reached, township by township, over time.
- Designated basinsThe eight basins outside the priority system, their management districts, and the permits filed in each.
Storage and the Colorado River
The reservoirs that decide Colorado's year, inside the state and downstream of it.
- Colorado River statusPowell and Mead against the elevations that decide operations, and the rule in force.
- ReservoirsStorage where DWR and Reclamation report it, by district.
- The Colorado River CompactLee Ferry, decade by decade.
Learn and reference
How Colorado water works, in short lessons, and the record behind the words.
- LessonsTwenty-four short lessons in five tracks, each with a quiz; a certificate at the end.
- ReferenceThe record behind the words: glossary, statutes and cases, institutions, timeline, each entry cited.
- GlossaryColorado water terms, one cited definition each.
- Statutes and casesTitle 37 article by article, and the decisions that made the doctrine.
- Who does whatAgencies, districts, cities, federal offices, universities, nonprofits.
- TimelineDated events from the San Luis People's Ditch to the post-2026 decision.
- How this is builtSources, definitions, and what each figure cannot tell you.
- Terms and disclaimersAdvisory reading aids, never administrative or legal conclusions.
Letters, markers and the community
The weekly letter, the signs on the water, and the door for telling us what is wrong.
- The letterState of the Call, weekly, by email; every issue sent is archived here, and the form to subscribe is on the map page.
- Water Here markersSmall signs by the water with a code to the page behind them.
- Marker partnersDistricts and ditches that host a marker.
- Report a problemEvery page has this door; this is the front one.
- Support the projectFree while in beta; what support pays for.
Machine-readable
For crawlers, agents and anyone who would rather have the file.
- llms.txtA short map of the site for language-model agents.
- Sitemap indexCore pages, every gage, and every decreed structure in chunks.
- robots.txtThe same paths are open to every agent; training crawlers are paced, not blocked.
All 76 water districts
- WD1 South Platte: Greeley to Balzac
- WD2 South Platte: Denver Gage to Greeley
- WD3 Cache La Poudre River
- WD4 Big Thompson River
- WD5 St. Vrain Creek
- WD6 Boulder Creek
- WD7 Clear Creek
- WD8 South Platte Cheesman to Denver Gage
- WD9 Bear Creek
- WD23 Upper South Platte
- WD48 Laramie River
- WD49 Republican River
- WD64 South Platte: Balzac to Stateline
- WD65 Arikaree River
- WD76 Sand Creek
- WD80 North Fork of South Platte
- WD10 Fountain Creek
- WD11 Arkansas: Headwaters to Salida
- WD12 Arkansas: Salida to Portland
- WD13 Wet Mountain Valley
- WD14 Arkansas: Portland to Fowler
- WD15 Saint Charles
- WD16 Cucharas River
- WD17 Arkansas: Fowler to Las Animas
- WD18 Apishapa River
- WD19 Purgatoire River
- WD67 Arkansas: Las Animas to Stateline
- WD79 Huerfano River
- WD20 Rio Grande
- WD21 Alamosa La Jara
- WD22 Conejos Creek
- WD24 Culebra Creek
- WD25 San Luis Creek
- WD26 Saguache Creek
- WD27 Carnero Creek
- WD35 Trinchera Creek
- WD28 Tomichi Creek
- WD40 North Fork/Tribs.
- WD41 Lower Uncompahgre River
- WD42 Lower Gunnison River
- WD59 East River Basin
- WD60 San Miguel River Basin
- WD61 Paradox Creek
- WD62 Upper Gunnison River
- WD63 Dolores River Basin
- WD68 Upper Uncompahgre River
- WD73 Little Dolores River
- WD36 Blue River Basin
- WD37 Eagle River Basin
- WD38 Roaring Fork River Basin
- WD39 Rifle/Elk/Parachute Creeks
- WD45 Divide Creek
- WD50 Muddy/Troublesome Creeks
- WD51 Upper Colorado/Fraser Rivers
- WD52 Piney/Cottonwood Creeks
- WD53 Tribs. North of Colorado River
- WD70 Roan Creek Basin
- WD72 Lower Colorado River
- WD43 White River Basin
- WD44 Lower Yampa River
- WD47 North Platte River Basin
- WD54 Slater/Timberlake Creeks
- WD55 Little Snake River
- WD56 Green River Basin
- WD57 Middle Yampa River
- WD58 Upper Yampa River
- WD29 San Juan River Basin
- WD30 Animas River Basin
- WD31 Los Pinos River Basin
- WD32 McElmo Creek Basin
- WD33 La Plata River Basin
- WD34 Mancos River Basin
- WD69 Disappointment Creek Basin
- WD71 West Dolores Creek/Tribs.
- WD77 Navajo River Basin
- WD78 Piedra River Basin
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