Hydrohistorian
Upper Uncompahgre River
Who may take water from the Upper Uncompahgre River, who is calling for it today, and how it is running, compiled from Colorado Division of Water Resources records. Click anything on the map for its record.
Upper Uncompahgre River on the ground — the ditches, wells, reservoirs and gages of Water District 68 · clicktap anything for its record
The well-permit cells in view, as a table
Each row is one ~1-mile cell (0.02°) with the permits the file spots inside it, split into water-supply permits and monitoring holes (DWR’s two monitoring categories: drilled to look at the water, not to pump it). These are permits, not wells: a permit is a piece of paper, and the file does not say which were drilled. Spotting is the file’s own, about a mile at best, which is why the cells are no finer.
| Lat | Lon | Water-supply permits | Monitoring holes |
|---|
Browse this district’s ditches, gages, reservoirs, wells and springs as a list.
The Uncompahgre River is below normal for late September -- 72% of normal flow. 1 call stands against it right now; the most senior right calling dates to 1998. DWR's statements do not settle whether 12 more calls reach it. This year's runoff outlook, issued 2026-06-01, called for 16% of normal.
Schematic
Historical
Evolution of the network
Trends
Source Our computation, no independent reference · computed here from the screened DWR record Source Our computation, no independent reference · no independent reference; see /methods
This year, in context
In the weeks around 2026-09-27 (the newest reading on file), flows at the 6 ranked gages are running at a median 151% of their own long-term norm for this window — 0 below a typical year, 6 at or above. Driest relative to its record: UNCOMPAHGRE RIVER NEAR RIDGWAY, CO., ranking 45th lowest of 68 years.
How this comparison is made
Each gage's mean flow over the 3 days either side of 2026-09-27, compared with the same window in every year of its own record — so a gage is only ever measured against itself, and gages with no record in the window are counted out rather than guessed.
Gage flow trend & changepoints
What counts as a trend here
Computed 2026-10-20 17:51 from 6 gage(s) with cached period-of-record data. The series is each gage's annual mean flow in cfsCubic feet per second, a rate of flow. One cfs running for a day is about 2 acre-feet. (years with ≥300 days of record). Mann-Kendall (trend, with the Hamed–Rao correction for serial correlation — persistence can otherwise fake significance) and Pettitt (changepoint) both require at least 8 years spanning at least 10 years of record. A gage below that reports no signal — which is not the same as “no change.” The %-per-decade figure is the same Sen slope divided by the gage's median annual flow, for comparing across streams of very different size; it is omitted for near-ephemeral channels where the median is too small to divide by honestly.
Of the 6 gages with enough record, 1 is trending down and 0 up, and 1 carries a detected shift. The clearest is Uncompahgre River at Colona, its annual mean flow changing -7.38 cfs per decade (-3.0% of its median annual flow) over 113 years (p=0.0067). The other 5 show no clear signal either way.
| Gage | Trend | Change / decade cfs · % of median annual flow | Significance | Years | Changepoint |
|---|---|---|---|---|---|
|
▸
Uncompahgre River at Colona UNCCOLCO |
↓ decreasing | -7.38 cfs -3.0% | p=0.007 | 113 | ~1949 |
5 other gage(s) show no significant trend or changepoint (not shown).
How the measurement network itself changed
This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 6 gage(s) and 178 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1970. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.
| Decade | Gages with data (median yr) | Structures reporting (median yr) |
|---|---|---|
| 1900s | 0 | 1 |
| 1910s | 1 | 0 |
| 1920s | 2 | 0 |
| 1930s | 1 | 0 |
| 1940s | 1 | 0 |
| 1950s | 2 | 0 |
| 1960s | 3 | 0 |
| 1970s | 2 | 100 |
| 1980s | 3 | 96 |
| 1990s | 4 | 113 |
| 2000s | 5 | 165 |
| 2010s | 6 | 172 |
| 2020s | 6 | 179 |
Mass-balance (network closure) trend
Structure divrec-history backfill coverage as of the last check: 11% of 1547 schematic-relevant structures. 0 year(s) clear the 30% coverage gate so far -- the trend activates automatically once qualifying years span a full decade. No action needed; the nightly backfill keeps extending the record.
Reach gain/loss shifts (1956–2026)
Mass-balance kinks computed for every summer month back to 1956 (816 reach-snapshots) — which reaches gain or lose water, and how that has shifted across decades. Each shift is cross-checked against the observation record above: as more diversions became metered, "unaccounted" water shrinks mechanically, which can masquerade as a hydrologic shift.
- UNCOMPAHGRE RIVER AT COLONA, CO.: reach shifted from +432 cfs to +41 cfs summer mean (more losing, p=0.000, 71 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=-0.57) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
- UNCOMPAHGRE RIVER BELOW RIDGWAY RESERVOIR, CO: reach shifted from +300 cfs to +202 cfs summer mean (more losing, p=0.044, 38 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
- UNCOMPAHGRE RIVER NEAR RIDGWAY, CO.: reach shifted from +62 cfs to +27 cfs summer mean (more losing, p=0.028, 26 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
Groundwater now has its own tab: 10 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.
Reservoirs now has its own tab: 11 reservoir(s), end-of-year storage back to 1974, click-to-chart histories.
Cross-gage pattern fingerprint
Over the 47-year window with full coverage (1980–2026), the dominant shared pattern across 3 gage(s) explains 94% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).
All gages in this window move with the shared pattern -- no localized outlier.
Structures most implicated by reconciliation (as of 2026-09-27)
Which structures' data absorbed the most correction when the current mass-balance snapshot was reconciled -- see the Historical tab for the full picture on any date.
- DAVE WOOD SPRING (return): +4.0 cfs (3% of that reach's correction)
- FAIRWAY PINES ESTATE OWNERS POND 1 (diversion): +4.0 cfs (3% of that reach's correction)
- FAIRWAY PINES ESTATE OWNERS POND 2 (diversion): +4.0 cfs (3% of that reach's correction)
- MCKENZIE CANAL (diversion): +4.0 cfs (3% of that reach's correction)
- HIGHLINE DITCH (diversion): +4.0 cfs (3% of that reach's correction)
- SHORTLINE DITCH (diversion): +4.0 cfs (3% of that reach's correction)
- JOSSI SPRING PIPELINE (return): +4.0 cfs (3% of that reach's correction)
- ERGEN SPRING #2 (return): +4.0 cfs (3% of that reach's correction)
- ERGEN SPRING #3 (return): +4.0 cfs (3% of that reach's correction)
- CALL DITCH (diversion): +4.0 cfs (3% of that reach's correction)
Data provenance & quality
Where these numbers come from and how far they can be trusted. Grade C (3/6 points) — the components below are the finding; the letter alone is not. Sources: DWR HydroBase snapshot HydroBase_CO_20260928 (imported 2026-10-04) for history, plus the CDSS REST API for current conditions.
| Check | State | What was measured |
|---|---|---|
| gage freshness | stale | newest gage reading is 23 day(s) old (target 7) |
| diversion record | expected-lag | newest diversion record is 354 day(s) old (DWR publishes ~1 year in arrears) |
| structure coverage | sparse | 11% of schematic structures have data |
Independent check: PASS — 100.0000% agreement across 199,147 stored values re-checked against DWR's authoritative record (HydroBase_CO_20260707), over 20 structures. 0 disagreement(s) beyond a 0.01 cfs tolerance. Checked 2026-08-19; a rotating sample covers the whole basin across successive runs, and the structures this report cites are checked every time.
Federal cross-check: PASS — 98.36% day-level agreement with USGS's own published records for the same gages, across 5 co-listed station(s) and 114,494 overlapping days (within max(2%, 0.5 cfs) daily). Pre-1950 records at some gages carry known between-agency day-stamp and transcription differences — scored at each year's best ±1-day alignment; residual disagreement is real historical divergence, flagged for review.
6 gage(s) / 120,979 daily values (1912-10-01–2026-09-27); 252 structure(s) with diversion records; 1293 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.
Groundwater
Source DWR administrative record · verify at DWR groundwater wells ↗ Source DWR administrative record · verify at DWR well permits ↗
24 water-level measurements across 10 monitored well(s) — 7 alluvial, 1 bedrock — plus 3 administered well(s) reporting metered pumping.
What is being counted
Observation wells and pumping wells are different populations and are never conflated: water levels come from monitored observation wells, and metered pumping comes from administered wells reporting through diversion records. Click any well to chart its own record.
Well map
3D aquifer x-ray
Every aquifer unit as its own head surface, animated through time.
How the surfaces are built, and what they are not
Alluvial water table on top, Denver Basin members (Dawson, Denver, Arapahoe, Laramie–Fox Hills) stacked beneath where measured, interpolated from measured water levels. Units are never mixed; a surface exists only inside its own unit's well coverage, with no extrapolation; thin epochs are suppressed and say why. Vertical scale is exaggerated for readability and z is head elevation in feet. These are measured heads, not a calibrated groundwater model.
Water-table trends
Of 0 well(s) with enough record for a trend test: 0 declining, 0 rising.
Stream corridors — the surface connection
Where a reach's gain or loss has shifted, the wells within two miles of its anchoring gage and what their water table did over the same era.
How the corridor is assembled
For each reach whose gain/loss has shifted (Trends tab): the wells within 2 miles of its anchoring gage, their pooled water-table history over the same era, and an advisory Glover screen of lagged stream depletion from nearby metered pumping. v1 proximity = distance to the reach's anchoring gage; segment-based reach join is a flagged upgrade.
UNCOMPAHGRE RIVER NEAR RIDGWAY, CO.: 2 alluvial well(s) nearby
Wells labeled by administrative world before anything else is said about them: tributary alluvium participates in the priority system; designated-basin and Denver Basin bedrock aquifers are governed differently and are excluded from stream-connection reasoning. Read bedrock declines differently too: deep bedrock aquifers recharge negligibly on human timescales, so a falling bedrock level is storage mining — effectively permanent — not a drought response that a wet year undoes. All screens advisory.
54% are constructed wells; 3% tie to a decreed structure. A permit is permission to drill, not a water right; most here are exempt household wells. More in three things called “well”, or turn on the Well permits chip on the map above to see where they sit.
Permits issued here, by year
842 located water-supply permits with an issue date, 1955 to 2026; half of them had been issued by 1998, and the busiest year was 1994 with 34. The district’s 141 monitoring holes are counted apart: they are drilled to look, not to pump. A permit is not a well, and the year is the date the paper was issued, not a drilling date. The 1,223 above counts every permit on file here; 240 of them have no usable location or no issue date and are not in this chart.
water-supply permits issued that year monitoring holes, when shown
The counts by year, as a table
| Year | Issued | Monitoring holes | Water-supply | Issued through that year |
|---|---|---|---|---|
| 1955 | 3 | 0 | 3 | 3 |
| 1956 | 4 | 0 | 4 | 7 |
| 1957 | 2 | 0 | 2 | 9 |
| 1961 | 2 | 0 | 2 | 11 |
| 1967 | 2 | 0 | 2 | 13 |
| 1968 | 1 | 0 | 1 | 14 |
| 1970 | 2 | 0 | 2 | 16 |
| 1971 | 2 | 0 | 2 | 18 |
| 1972 | 15 | 0 | 15 | 33 |
| 1973 | 18 | 0 | 18 | 51 |
| 1974 | 17 | 0 | 17 | 68 |
| 1975 | 4 | 0 | 4 | 72 |
| 1976 | 4 | 0 | 4 | 76 |
| 1977 | 13 | 0 | 13 | 89 |
| 1978 | 17 | 0 | 17 | 106 |
| 1979 | 18 | 0 | 18 | 124 |
| 1980 | 14 | 0 | 14 | 138 |
| 1981 | 23 | 0 | 23 | 161 |
| 1982 | 23 | 0 | 23 | 184 |
| 1983 | 32 | 5 | 27 | 216 |
| 1984 | 9 | 0 | 9 | 225 |
| 1985 | 10 | 0 | 10 | 235 |
| 1986 | 12 | 0 | 12 | 247 |
| 1987 | 18 | 0 | 18 | 265 |
| 1988 | 16 | 4 | 12 | 281 |
| 1989 | 14 | 3 | 11 | 295 |
| 1990 | 19 | 7 | 12 | 314 |
| 1991 | 16 | 2 | 14 | 330 |
| 1992 | 36 | 18 | 18 | 366 |
| 1993 | 20 | 11 | 9 | 386 |
| 1994 | 41 | 7 | 34 | 427 |
| 1995 | 16 | 5 | 11 | 443 |
| 1996 | 24 | 6 | 18 | 467 |
| 1997 | 24 | 4 | 20 | 491 |
| 1998 | 29 | 14 | 15 | 520 |
| 1999 | 23 | 3 | 20 | 543 |
| 2000 | 17 | 2 | 15 | 560 |
| 2001 | 18 | 0 | 18 | 578 |
| 2002 | 29 | 2 | 27 | 607 |
| 2003 | 15 | 3 | 12 | 622 |
| 2004 | 21 | 1 | 20 | 643 |
| 2005 | 18 | 0 | 18 | 661 |
| 2006 | 19 | 0 | 19 | 680 |
| 2007 | 18 | 0 | 18 | 698 |
| 2008 | 8 | 4 | 4 | 706 |
| 2009 | 20 | 6 | 14 | 726 |
| 2010 | 9 | 0 | 9 | 735 |
| 2011 | 24 | 0 | 24 | 759 |
| 2012 | 15 | 4 | 11 | 774 |
| 2013 | 7 | 2 | 5 | 781 |
| 2014 | 9 | 1 | 8 | 790 |
| 2015 | 6 | 1 | 5 | 796 |
| 2016 | 12 | 2 | 10 | 808 |
| 2017 | 11 | 0 | 11 | 819 |
| 2018 | 15 | 1 | 14 | 834 |
| 2019 | 19 | 4 | 15 | 853 |
| 2020 | 18 | 5 | 13 | 871 |
| 2021 | 23 | 4 | 19 | 894 |
| 2022 | 17 | 1 | 16 | 911 |
| 2023 | 21 | 2 | 19 | 932 |
| 2024 | 21 | 7 | 14 | 953 |
| 2025 | 13 | 0 | 13 | 966 |
| 2026 | 17 | 0 | 17 | 983 |
Every district in the file on one scale · the whole file, one year at a time · Plate 4 of the Driller’s Atlas.
What drillers reached, township by township
12 PLSS townships here where at least 5 water-supply permits naming the same aquifer filed a depth (786 permits in all). Each column is one township, six miles square, on one scale to 800 ft below ground: a faint lane spans the 10th to 90th percentile of where the permits naming that aquifer stopped, the solid band their screens, the tick the median. This is the permit file’s view of the ground — the aquifer is the name the driller wrote, the band is where those holes ended — not a geologic map, and a township is as fine as it gets. Monitoring holes are left out. 6 of these townships straddle a district line and are filed here because most of their permits are.
140 · 57% here
136
131
96
95 · 62% here
63
44
29 · 61% here
24 · 71% here
10
10 · 89% here
8 · 44% here
unnamed other named faint = where the permits naming it stopped (10th–90th pct) · solid = their screens · tick = median · ft below ground as filed
Every township here, as a table
| Township | Share of its permits in this district | Aquifer named | Permits with a depth | Drilled depth p10 / p50 / p90, ft | Screen top p10 / p50 / p90, ft | Screen bottom p10 / p50 / p90, ft |
|---|---|---|---|---|---|---|
| T47N R9W New Mexico PM | 57% | other named | 11 | 120 / 260 / 384 | 90 / 164 / 260 | 120 / 220 / 384 |
| T47N R9W New Mexico PM | 57% | unnamed | 128 | 93 / 300 / 602 | 108 / 220 / 521 | 188 / 302 / 602 |
| T46N R9W New Mexico PM | 99% | unnamed | 123 | 143 / 250 / 398 | 48 / 127 / 255 | 121 / 222 / 382 |
| T46N R9W New Mexico PM | 99% | other named | 11 | 144 / 278 / 300 | 70 / 82 / 158 | 138 / 230 / 289 |
| T45N R8W New Mexico PM | 100% | unnamed | 127 | 41 / 120 / 351 | 28 / 95 / 327 | 39 / 130 / 371 |
| T44N R8W New Mexico PM | 98% | unnamed | 93 | 51 / 200 / 589 | 80 / 140 / 482 | 138 / 210 / 632 |
| T47N R10W New Mexico PM | 62% | other named | 10 | 145 / 240 / 412 | 87 / 185 / 288 | 145 / 235 / 420 |
| T47N R10W New Mexico PM | 62% | unnamed | 84 | 201 / 302 / 402 | 124 / 200 / 341 | 223 / 302 / 402 |
| T45N R9W New Mexico PM | 99% | unnamed | 54 | 53 / 291 / 642 | 71 / 226 / 729 | 114 / 312 / 789 |
| T45N R9W New Mexico PM | 99% | other named | 9 | 256 / 445 / 473 | 216 / 380 / 413 | 256 / 445 / 473 |
| T46N R8W New Mexico PM | 98% | unnamed | 41 | 53 / 183 / 405 | 40 / 91 / 223 | 103 / 221 / 431 |
| T47N R8W New Mexico PM | 61% | unnamed | 29 | 25 / 60 / 301 | 66 / 104 / 335 | 70 / 143 / 475 |
| T46N R10W New Mexico PM | 71% | other named | 6 | 133 / 164 / 336 | 53 / 102 / 276 | 133 / 164 / 336 |
| T46N R10W New Mexico PM | 71% | unnamed | 18 | 89 / 279 / 376 | 42 / 104 / 241 | 76 / 279 / 377 |
| T44N R7W New Mexico PM | 100% | unnamed | 10 | 87 / 280 / 442 | — | — |
| T44N R9W New Mexico PM | 89% | unnamed | 7 | 97 / 180 / 769 | 66 / 120 / 736 | 95 / 180 / 769 |
| T47N R11W New Mexico PM | 44% | unnamed | 7 | 100 / 135 / 309 | — | — |
These columns on the map · Plate 6 of the Driller’s Atlas.
The Driller’s Atlas · Plate 2 A cross-section nobody surveyed
Every permitted well within a few miles of the line, drawn from the ground to its drilled depth as the driller filed it. The bright part of each stroke is the perforated casing — where the well actually takes water — coloured by the aquifer named on the permit. Nobody arranged these; the aquifers arrange themselves.
The ground each well hangs from is a 1-km elevation model sampled at the point the permit was spotted, so the profile is real topography smoothed to about a kilometre — peaks are shaved, valleys filled a little — and the depths are the driller’s, measured down from that ground.
Hover or arrow through the strokes to read a well.
The same corridor as a table
| Miles from A | Wells drawn | Median depth (ft) | With a screen | Most-named aquifer | No depth filed | Ground, ft above sea level (median) |
|---|
Bins run from end A to end B of the line. “Most-named aquifer” is the family most often named on permits in the bin, with its count; permits naming no aquifer are the majority of the file and are not a family.
Reservoirs
Source DWR administrative record · verify at DWR structure records ↗
11 reservoir(s) with 2,090 storage measurement(s), 1974–2026. Basin storage as of 2025-10-31 (the record's own end — reservoir records publish ~annually): 66,111 AF across 1 reservoir(s).
Why storage matters to the flow network
Storage change is real water the mass balance must credit — a losing reach beside a filling reservoir isn't losing water, it's banking it.
Reservoir map — how full is each vessel?
What “full” is measured against
Bubble size is proportional to a reservoir's record-high storage. Fill is its last recorded storage as a share of its surveyed capacity (USACE National Inventory of Dams) where a confident NID match exists — the tooltip names the matched dam — and as a share of its own record high otherwise. A wrong capacity would be worse than an honest record high, so only confident joins upgrade.
A dashed teal ring marks reservoirs reporting live DWR telemetry: their fill reflects yesterday's storage, is drawn as a dotted tail on charts, and is treated as provisional until the next verified HydroBase snapshot supersedes it.
A dashed red ring marks a dam under an active storage restriction from DWR's Dam Safety branch — the State Engineer has limited how much it may legally store, so a low fill can be an order, not a drought. Hazard class and inspection condition come from the same record, joined only where the dam carries this reservoir's WDID or a confident NID match — a wrong dam's restriction would be worse than none shown.
Basin storage, end of each water year
End-of-water-year totals; per-year reservoir counts shown because reporting coverage varies -- a total is only comparable to years with similar counts.
Largest reservoirs on record
Click a row to chart its full storage history, or open its dossier for rights, documents and dam-safety facts.
| Reservoir | Last recorded storage (AF) | As of | Full | Dam (DWR Dam Safety) | |
|---|---|---|---|---|---|
| ▸ RIDGWAY RESERVOIR TRI CT (6803675) | 66,111 | 2025-10-31 | — | — | dossier → |
| ▸ CORNERSTONE RESERVOIR NO4 (6803847) | 117 | 2011-06-11 | — | — | dossier → |
| ▸ PTARMIGAN LAKE (6803686) | 29 | 2022-03-31 | — | — | dossier → |
| ▸ FAIRWAY PINES RESERVOIR (6803836) | 13 | 2012-04-30 | — | — | dossier → |
| ▸ BATES NO2 RESERVOIR (6803562) | 10 | 1989-05-09 | — | — | dossier → |
| ▸ VICTOR RES NO 9 (6803580) | 8 | 1974-07-20 | — | — | dossier → |
| ▸ DOUBLE RL LAKE NO 1 (6803783) | 5 | 2023-10-31 | — | — | dossier → |
| ▸ JACQUES RES NO 1 (6803569) | 1 | 1974-08-20 | — | — | dossier → |
Snow and runoff
Source Independent agency measurement · fetched 2026-10-21 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record
Snow-water equivalent, WY2027
A trace of snow at 1 of 1 sites (0.1 in of water at most); the median for the date is zero, so there is no percent to show yet. The snow year begins in October. The new water year began October 1; the chart fills in a day at a time as NRCS publishes each reading.
| SNOTEL site | Elev (ft) | SWE (in) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Idarado | 9780 | 0.1 | 0.0 | — | April 6 (14.4 in) |
NRCS SNOTEL, daily. Sites are assigned to the district whose boundary contains them — the snow that feeds this district can also sit in a neighboring headwater district.
Two ways a snow year goes wrong (1981–2026)
A bad snow year here comes in two flavors (both called snow droughtA winter that shorts the snowpack. It happens two ways: a dry one, where the snow never comes, and a warm one, where near-normal snow falls but melts off weeks early -- and the river feels them differently.), and the river feels them differently. In 10 of the last 46 winters the snow never came — the pack peaked below 80% of its median. In 1 more, the snow came but left early — a near-normal peak melted out two weeks or more ahead of its usual date, sending the water down before the season needed it.
The snow never came: 1981, 1988, 1990, 2001, 2002, 2007, 2012, 2013, 2018, 2026. The snow left early: 1989.
Computed by this site from 1 SNOTEL site’ full daily records (NRCS AWDB, back to 1981). Each year is measured against each site’s own multi-decade median — not the 1991–2020 normal the chart above uses — so the 1980s grade against a fair baseline. Peak and melt-out need 85% of the season’s days on the record; thin years are dropped, not guessed. Derived from snow measurements alone — it cannot tell dry-from-warm causes apart, only what the snowpack did.
Runoff outlook — Ridgway Reservoir Inflow
NRCS's final issue (2026-06-01) calls it even odds that at least 14 kAF arrives over 06-01 to 07-31 — 22% of a normal season; almost certainly at least 6, probably not more than 22. Our own record at this gage shows 15 kAF actually delivered. New forecasts begin in January. How to read these numbers →
We test a record-based adjustment of the April benchmark at every graded point. Here it did not beat NRCS over 31 replayed seasons (20% typical miss unadjusted vs 23% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →
| 90% chance of at least | 70% chance of at least | 50% chance of at least | 30% chance of at least | 10% chance of at least | Normal | Observed |
|---|---|---|---|---|---|---|
| 6 | 12 | 14 | 17 | 22 | 61 | 15 |
How good are these forecasts here? (1993–2025)
Grading every April issue against what the river then delivered, measured at this gage’s own record — 32 seasons: the median miss of the 50% forecast is 21%, with a high bias of 11%, and the observed volume landed inside the stated 10–90% band 69% of the time (a calibrated forecast would say 80%).
Computed by this site: NRCS's archived April issues (their period as issued each year) against the observed volume in DWR’s published record; years with under 90% daily coverage are dropped, not summed. A grade of the forecast, never of the forecasters — these are hard rivers. How this point ranks among every graded Colorado forecast point →
What April snow has meant for this river (1989–2026)
Across 38 measured years, the season’s water has closely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 84% of a normal season (a snow-to-runoff elasticityHow strongly one number moves with another. A snow-to-runoff elasticity of 1.5 means a 10% shortfall in April snowpack has typically become a 15% shortfall in the season's water. of 0.7). In warm, early-melt years the river delivered a median of 51% of a normal season, against 112% in typical years — the timing of the melt matters, not just its size.
Computed by this site: the district’s April 1 SWE (% of each SNOTEL site’s own-record median) against the observed April–July volume at this gage (% of its median season) — a fixed window every year, unlike the forecast grades above, which use each issue’s own period. The slope is fit so single wild years can’t steer it (Theil–Sen, log space); years missing 10% of their days are dropped.
Runoff outlook — Uncompahgre R at Colona
NRCS's final issue (2026-06-01) calls it even odds that at least 12 kAF arrives over 06-01 to 07-31 — 16% of a normal season; almost certainly at least 7, probably not more than 24. Our own record at this gage shows 10 kAF actually delivered. New forecasts begin in January. How to read these numbers →
We test a record-based adjustment of the April benchmark at every graded point. Here it did not beat NRCS over 69 replayed seasons (22% typical miss unadjusted vs 22% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →
| 90% chance of at least | 70% chance of at least | 50% chance of at least | 30% chance of at least | 10% chance of at least | Normal | Observed |
|---|---|---|---|---|---|---|
| 7 | 10 | 12 | 17 | 24 | 74 | 10 |
How good are these forecasts here? (1950–2025)
Grading every April issue against what the river then delivered, measured at this gage’s own record — 75 seasons: the median miss of the 50% forecast is 24%, with a high bias of 7%, and the observed volume landed inside the stated 10–90% band 78% of the time (a calibrated forecast would say 80%).
Computed by this site: NRCS's archived April issues (their period as issued each year) against the observed volume in DWR’s published record; years with under 90% daily coverage are dropped, not summed. A grade of the forecast, never of the forecasters — these are hard rivers. How this point ranks among every graded Colorado forecast point →
What April snow has meant for this river (1981–2026)
Across 46 measured years, the season’s water has closely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 64% of a normal season (a snow-to-runoff elasticityHow strongly one number moves with another. A snow-to-runoff elasticity of 1.5 means a 10% shortfall in April snowpack has typically become a 15% shortfall in the season's water. of 1.2). In warm, early-melt years the river delivered a median of 38% of a normal season, against 100% in typical years — the timing of the melt matters, not just its size.
Computed by this site: the district’s April 1 SWE (% of each SNOTEL site’s own-record median) against the observed April–July volume at this gage (% of its median season) — a fixed window every year, unlike the forecast grades above, which use each issue’s own period. The slope is fit so single wild years can’t steer it (Theil–Sen, log space); years missing 10% of their days are dropped.
Drought
Source Our computation, no independent reference · computed here from the screened DWR record Source Independent agency measurement · fetched 2026-10-13 · verify at U.S. Drought Monitor ↗
Right now
This is the 82nd-driest week 39 in 114 years of record at UNCOMPAHGRE RIVER AT COLONA, CO. (as of 2026-09-21; this week’s flow sits at the 72nd percentileRank against the record: a river at its 5th percentile is lower than it was in 95 of the past 100 years on this same date. for the date). On this week’s US Drought Monitor, San Juan County is 23% in D1 moderate drought (2026-10-13). The law agrees: the most senior active call leaves 25% of this district’s decreed flow rights junior to the calling right this week.
Every year since 1912, week by week
Each thin row is a year at UNCOMPAHGRE RIVER AT COLONA, CO.; each cell is one week’s flow ranked against the same calendar week of every other year — warm means dry for the date, blue wet, so seasonality cancels and droughts appear as warm bands. Gaps are missing record, never a dry river. Click a year to reconstruct it on the Historical tab.
This year against its analogs
Over the 38 weeks recorded so far, 2026’s weekly trace most resembles 2002 (mean gap 10.1 percentile points; next closest 2013 (13.3), 2021 (15.6)). The analog’s remainder is drawn as context — its ending is what happened to it, not a forecast for this year.
The Drought Monitor’s view since 2000
Mean share of area in each class across Ouray, San Juan counties — the counties this district’s gages sit in, which overlap the district imperfectly. The Drought Monitor weighs soils, vegetation and local reports; it is CONTEXT beside the river’s own record above, not the water-rights picture.
The law’s own drought gauge
When water runs short, administration answers: calls reach further back in time, and more decreed rights go junior to the calling right. This is that response, weekly since 2003 — the share of this district’s decreed flow rights junior to the most senior active call. Watch it spike in the named droughts below, and linger after the river recovers.
Computed from DWR’s call record (35 calls touching this district) against the district’s rights index. Scoping is deliberately coarse — a call’s own district, or districts named in its comments — and this is administration’s RESPONSE, not a per-structure verdict (each dossier’s curtailment card does that, with stream miles). A deepening call can also reflect growing demand, not only shrinking supply.
This basin’s droughts, by its own record
| Drought | Span | Weeks | Trough percentile | Flows recovered | Water table back |
|---|---|---|---|---|---|
| unnamed dry spell | 2025-06-09 → 2026-09-21 | 67 | 3rd (2026-08-03) | not yet | — |
| unnamed dry spell | 2024-01-22 → 2024-11-04 | 41 | 5th (2024-04-08) | not yet | — |
| the 2020-22 drought | 2020-02-10 → 2023-06-19 | 175 | 7th (2021-03-22) | 2 weeks | — |
| the 2018 drought | 2018-03-05 → 2019-09-09 | 79 | 3rd (2019-03-04) | 0 weeks | — |
| the 2012-13 drought | 2012-07-23 → 2013-11-25 | 70 | 4th (2013-05-27) | 6 weeks | — |
| unnamed dry spell | 2010-01-25 → 2010-07-12 | 24 | 16th (2010-03-22) | 6 weeks | — |
| the 2002 drought | 2002-03-25 → 2003-11-03 | 84 | 2nd (2003-04-14) | 43 weeks | — |
| the 2002 drought | 2000-11-13 → 2001-07-23 | 36 | 20th (2001-04-02) | 10 weeks | — |
| unnamed dry spell | 2000-03-13 → 2000-09-18 | 27 | 16th (2000-04-24) | 54 weeks | — |
| unnamed dry spell | 1989-08-21 → 1990-11-26 | 66 | 8th (1990-04-23) | 7 weeks | — |
| unnamed dry spell | 1988-07-25 → 1989-01-30 | 27 | 17th (1988-08-29) | 4 weeks | — |
| the 1981 drought | 1980-09-08 → 1981-12-07 | 65 | 18th (1981-07-06) | 5 weeks | — |
| the 1977 drought | 1977-05-16 → 1978-05-22 | 53 | 10th (1977-10-24) | 8 weeks | — |
| the 1977 drought | 1976-08-23 → 1977-02-14 | 25 | 24th (1976-09-20) | 74 weeks | — |
Detected mechanically: the 26-week smoothed percentile below the 30th for at least 20 weeks; recovered on regaining the 50th. The water-table clock compares each monitoring well against its own pre-drought median (the 3 years before onset) and dates the year the median well got back — the aquifer remembers longest, and “still below” is a finding, not a gap. The knobs are stated because the episode list depends on them — a different reasonable choice merges or splits episodes at the edges. Names are attached where an episode overlaps a drought Colorado already talks about.
When this basin claimed its water
Every bar is a year’s new appropriations (1,039 rights across 115 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is -0.01 — essentially no wet-dry pattern; here, law and settlement set the pace, not the weather. Across the state both behaviors exist: ephemeral southwest basins file after wet demonstrations, transbasin-source basins under drought — and the biggest statewide filing waves sat in the 1950s drought and after 2002, not in the wet 1980s–90s.
Appropriation dates are the CLAIMED initiation of a right, not the courthouse filing date; the record is survivor-biased (abandoned claims are absent, so failed dry-era scrambles are undercounted); and the big 1960s and 2000s spikes sit on legal events — the pre-1969-Act adjudication era and 2000s legislation — not on weather. A correlation here is a description, never a cause.
New to how a dry winter becomes a call on the river? Anatomy of a drought walks the chain in four minutes — snow to rivers to reservoirs to calls to the water table.
Legal
Who serves it, who protects it
Two registers the site fetches on their own schedules, read for this district. Neither is a DWR record; each links its own page and its agency.
Public water systems here
Source Register of another agency · fetched 2026-10-06 · verify at EPA SDWIS ↗
5 systems touch this district (5 community systems reporting 3,869 people served, a figure that counts a wholesaler's customers twice); none carries an open health-based violation on EPA's record.
| System | Serves | Source | Here |
|---|---|---|---|
| OURAY CITY OF | 1,460 | Groundwater under the influence of surface water | 100% of its area |
| DALLAS CREEK WC | 1,059 | Surface water | 100% of its area |
| RIDGWAY TOWN OF | 1,000 | Surface water | 100% of its area |
| ELK MEADOWS ESTATES | 230 | Groundwater under the influence of surface water | 100% of its area |
| DALLAS MEADOWS COMMUNITY ASSOC | 120 | Groundwater | 100% of its area |
Instream-flow rights held by the state
Source Register of another agency · fetched 2026-10-18 · verify at CWCB instream flow program ↗
15 reaches over 82.4 miles and 6 natural lake levels, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →
- East Fork Spring Creek, 8.75 mi: 1.8 (4/1 - 10/31), 1.6 (11/1 - 3/31) cfs (appropriated 2006, 06CW0167) · dossier
- Beaver Creek, 8.7 mi: 1.5 (1/1 - 12/31) cfs (appropriated 1984, 84CW0425) · dossier
- Cow Creek, 7.4 mi: 7.2 (01/01 - 03/31), 20 (04/01 - 04/30), 53 (05/01 - 06/30), 20 (07/01 - 07/31), 15 (08/01 - 08/15), 7.2 (08/16 - 08/28), 5.9 (08/29 - 09/19), 7.2 (09/20 - 12/31) cfs (appropriated 2021, 21CW3064)
- Cow Creek, 7.0 mi: 18 (4/1 - 7/31), 5 (8/1 - 3/31) cfs (appropriated 1984, 84CW0420) · dossier
- West Fork Dallas Creek, 6.3 mi: 2.5 (1/1 - 12/31) cfs (appropriated 1984, 84CW0423) · dossier
- Middle Fork Spring Creek, 6.04 mi: 3.5 (4/1 - 10/31), 1.5 (11/1 - 3/31) cfs (appropriated 2006, 06CW0169) · dossier
and 15 more on the district's instream-flow page.
What the water is like -- USGS sensors right now, where it has been sampled, the impaired-waters list, and how the tap water here stands with EPA -- is on the Water quality tab.
Designated groundwater basins are on their own page.
Source Adjudicated record · verify at DWR water-right transactions ↗ Source Adjudicated record · verify at DWR net amounts ↗
Decreed rights on this network run from 1875-08-01 to 2025-01-27. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 52% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 144 compliance flags are listed below as leads for review — a screen is not an abandonment and a flag is not a violation.
Rights on file: 1583 across 1293 structure(s); 344 structure(s) carry 0 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.
Is the river getting harder to divert from?
Over 2003–2025, administration on this district has been tightening: 1 of 3 measures (days under callA senior water right demanding its water, which requires everyone junior on that stream to stop diverting until it is satisfied., calls set, seniorityColorado shares water by date: the earlier the right, the stronger its claim when the river runs short. "First in time, first in right." of the controlling call) are moving toward more administration, none the other way.
The three measures, year by year
One row per whole calendar year inside the call record's coverage (23 years); partly-covered years are omitted rather than reported as quiet. Trend is Mann-Kendall with the same significance gate as every other trend on this site. Counted from DWR's published call record, which begins in the early 2000s: earlier years are absent, not quiet. A rise in the number of calls set can also reflect how finely an administrator records one episode, which is why days under call -- insensitive to that -- is the component to read first. Advisory summary of the public record, not an administrative finding.
| Year | Days under call | Calls set | Controlling priority (median) |
|---|---|---|---|
| 2014 | 0 | 0 | — |
| 2015 | 277 | 127 | 1885-08-11 |
| 2016 | 366 | 108 | 1890-11-17 |
| 2017 | 319 | 94 | 1888-01-23 |
| 2018 | 291 | 160 | 1882-06-01 |
| 2019 | 319 | 93 | 1888-01-25 |
| 2020 | 246 | 141 | 1881-12-17 |
| 2021 | 275 | 103 | 1883-05-05 |
| 2022 | 365 | 93 | 1884-11-01 |
| 2023 | 277 | 59 | 1898-10-15 |
| 2024 | 275 | 56 | 1883-06-01 |
| 2025 | 365 | 100 | 1884-11-01 |
Why diversions stopped — call-based explanations
Sustained diversion stops matched to senior administrative calls.
- CARROLL DITCH (6800519) DWR↗ stopped 2025-08-07 (12+ days) — call at MOODY DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DALLAS PLACER DITCH (6800545) DWR↗ stopped 2025-08-03 (22+ days) — call at CRAWFORD CLIPPER DITCH curtailing 100% of its decreed rate [heuristic-partial]
- DAINE DITCH (6800542) DWR↗ stopped 2025-07-28 (86+ days) — call at MINNESOTA CANAL curtailing 100% of its decreed rate [heuristic-strong]
- BARKER DITCH (6800506) DWR↗ stopped 2025-07-22 (99+ days) — call at MINNESOTA CANAL curtailing 90% of its decreed rate [heuristic-partial]
- DOC WADE DITCH (6800559) DWR↗ stopped 2025-07-22 (77+ days) — call at MINNESOTA CANAL curtailing 55% of its decreed rate [heuristic-partial]
- CASSIDY DITCH (6800520) DWR↗ stopped 2025-07-07 (81+ days) — call at GROVE DITCH curtailing 67% of its decreed rate [heuristic-partial]
- CHAFFEE DITCH (6800523) DWR↗ stopped 2025-07-06 (21+ days) — call at GROVE DITCH curtailing 66% of its decreed rate [heuristic-partial]
- BROOKE DITCH (6800510) DWR↗ stopped 2025-06-12 (106+ days) — call at MIDKIFF & ARNOLD D curtailing 100% of its decreed rate [heuristic-strong]
- BROWN DITCH (6800511) DWR↗ stopped 2025-06-12 (131+ days) — call at MIDKIFF & ARNOLD D curtailing 62% of its decreed rate [heuristic-partial]
- BURGER DITCH (6800513) DWR↗ stopped 2025-06-10 (141+ days) — call at MIDKIFF & ARNOLD D curtailing 100% of its decreed rate [heuristic-strong]
- CLIMAX DITCH (6800531) DWR↗ stopped 2025-05-22 (21+ days) — call at COAL CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- CANNON DITCH (6800516) DWR↗ stopped 2025-05-20 (160+ days) — call at COAL CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
Right yield — how often could these rights actually divert?
Share of irrigation-season days each structure's rights were not called out, derived from the 22-year district-scoped call record (senior right = floor, junior right = ceiling constraint). Call-record-derived; DWR's own analysis governs where available.
| Structure | Senior priority | Senior right: median / dry yr | Junior right: median / dry yr |
|---|---|---|---|
| HYDROPLANT RIDGWAY RESERVOIR DAM (6801369) DWR↗ | 1956-11-06 | 0.0% / 0.0% | 0.0% / 0.0% |
| RIDGWAY RES EXCHANGE PLAN (6808334) DWR↗ | 1991-06-04 | 0.0% / 0.0% | 0.0% / 0.0% |
| RIDGWAY RESERVOIR TRI CT (6803675) DWR↗ | 1956-11-16 | 0.0% / 0.0% | 0.0% / 0.0% |
| UNCOMPAHGRE RIVER (6801456) DWR↗ | 1998-07-13 | 0.0% / 0.0% | 0.0% / 0.0% |
| OURAY HYDRO ELEC PROJ259 (6800682) DWR↗ | 1902-07-01 | 0.0% / 0.0% | 0.0% / 0.0% |
| DALLAS DITCH (6800543) DWR↗ | 1880-10-01 | 73.4% / 8.9% | 0.0% / 0.0% |
| GLACIER D WATER RIGHT (6800861) DWR↗ | 1896-04-21 | 0.0% / 0.0% | 0.0% / 0.0% |
| ALKALI DITCH D NO 80 (6800501) DWR↗ | 1884-10-15 | 22.4% / 0.0% | 0.0% / 0.0% |
| ALKALI NO 2 DITCH (6800502) DWR↗ | 1882-08-01 | 51.9% / 0.0% | 0.0% / 0.0% |
| SNEVA DITCH (6800738) DWR↗ | 1881-10-15 | 69.2% / 8.9% | 0.0% / 0.0% |
| MCDONALD DITCH NO 145 (6800657) DWR↗ | 1881-11-01 | 69.2% / 8.9% | 0.0% / 0.0% |
| RIDGWAY DITCH (6800710) DWR↗ | 1882-06-01 | 51.9% / 0.0% | 6.5% / 0.0% |
Abandonment radar (25 screens)
Absolute rights with 10+ years of no recorded diversions. Screens only — storage, alternate points, and plan operations can explain nonuse lawfully. And diversion REPORTING itself only reached its modern level ~1970 — idleness that begins before then may be unreported use, not nonuse (flagged † below).
- FISHER DITCH (6800577) DWR↗ (1904-07-01, 1.2 cfs decreed): last active 1950 — 75 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1970) -- early absence of record is weak evidence of nonuse
- MILLS LATERAL DITCH (6800665) DWR↗ (1909-05-01, 0.8 cfs decreed): last active 1950 — 75 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1970) -- early absence of record is weak evidence of nonuse
- WEST SIDE DITCH (6800776) DWR↗ (1883-05-01, 2.0 cfs decreed): last active 1950 — 75 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1970) -- early absence of record is weak evidence of nonuse
- ZENA NO 1 SPRING (6800783) DWR↗ (1914-01-19, 0.1 cfs decreed): last active 1950 — 75 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1970) -- early absence of record is weak evidence of nonuse
- CATTLE D & WTR SUPPLY (6800521) DWR↗ (1967-07-18, 0.5 cfs decreed): last active 1968 — 57 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1970) -- early absence of record is weak evidence of nonuse
- KRAFFT DITCH (6800632) DWR↗ (1913-11-18, 1.5 cfs decreed): last active 1970 — 55 years idle
- WEBER SPRING POND (6800957) DWR↗ (1910-05-01, 0.0 cfs decreed): last active 1971 — 54 years idle
- BEAR GULCH DITCH (6800507) DWR↗ (1908-06-01, 5.0 cfs decreed): last active 1974 — 51 years idle
- HUGHES LAKE DITCH (6800611) DWR↗ (1911-07-08, 0.5 cfs decreed): last active 1974 — 51 years idle
- PHILLIPS D & WTR SUPPLY (6800689) DWR↗ (1963-06-10, 0.6 cfs decreed): last active 1974 — 51 years idle
Compliance screens (144 advisory flags)
Screened 211 of 1293 structures with rights (218 have diversion history on file). A flag is a lead for expert review — augmentation plans, exchanges, and free-river conditions can make over-decree diversions lawful and are deliberately not modeled.
- RIDGWAY RESERVOIR TRI CT (6803675) DWR↗: Observed p99 daily rate 504.0 cfs (max 1400.0) exceeds total decreed absolute 133.0 cfs across 75127 recorded day(s).
- ALKALI DITCH D NO 80 (6800501) DWR↗: Observed p99 daily rate 45.0 cfs (max 48.0) exceeds total decreed absolute 39.5 cfs across 26106 recorded day(s).
- CHARLEY LOGAN DITCH (6800526) DWR↗: Observed p99 daily rate 30.0 cfs (max 39.0) exceeds total decreed absolute 15.7 cfs across 28014 recorded day(s).
- PINION DITCH (6800692) DWR↗: Observed p99 daily rate 24.1 cfs (max 29.0) exceeds total decreed absolute 22.7 cfs across 21812 recorded day(s).
- DOC WADE DITCH (6800559) DWR↗: Observed p99 daily rate 23.7 cfs (max 27.2) exceeds total decreed absolute 20.5 cfs across 10511 recorded day(s).
- HOMESTRETCH DITCH (6800607) DWR↗: Observed p99 daily rate 22.1 cfs (max 26.9) exceeds total decreed absolute 14.0 cfs across 23009 recorded day(s).
- PARK DITCH (6800685) DWR↗: Observed p99 daily rate 22.1 cfs (max 25.0) exceeds total decreed absolute 21.0 cfs across 18077 recorded day(s).
- BURKHART EDDY DITCH (6800514) DWR↗: Observed p99 daily rate 21.7 cfs (max 28.9) exceeds total decreed absolute 15.0 cfs across 19333 recorded day(s).
- MOODY DITCH (6800668) DWR↗: Observed p99 daily rate 21.3 cfs (max 37.2) exceeds total decreed absolute 9.9 cfs across 28465 recorded day(s).
- HOSNER BROWNYARD DITCH (6800609) DWR↗: Observed p99 daily rate 20.0 cfs (max 25.0) exceeds total decreed absolute 13.1 cfs across 23694 recorded day(s).
Seniority (top structures by decreed rate)
| Structure | Senior priority date | Rights | Decreed abs (cfs) | Decreed abs (AF) | Conditional? |
|---|---|---|---|---|---|
| HYDROPLANT RIDGWAY RESERVOIR DAM (6801369) DWR↗ | 1956-11-06 | 2 | 575.8 | 0 | yes |
| RIDGWAY RES EXCHANGE PLAN (6808334) DWR↗ | 1991-06-04 | 1 | 159.0 | 0 | yes |
| RIDGWAY RESERVOIR TRI CT (6803675) DWR↗ | 1956-11-16 | 4 | 133.0 | 208432 | yes |
| UNCOMPAHGRE RIVER (6801456) DWR↗ | 1998-07-13 | 1 | 65.0 | 0 | — |
| OURAY HYDRO ELEC PROJ259 (6800682) DWR↗ | 1902-07-01 | 1 | 60.0 | 0 | — |
| DALLAS DITCH (6800543) DWR↗ | 1880-10-01 | 6 | 41.4 | 0 | — |
| GLACIER D WATER RIGHT (6800861) DWR↗ | 1896-04-21 | 1 | 41.0 | 0 | — |
| ALKALI DITCH D NO 80 (6800501) DWR↗ | 1884-10-15 | 6 | 39.5 | 0 | — |
| ALKALI NO 2 DITCH (6800502) DWR↗ | 1882-08-01 | 9 | 36.7 | 0 | — |
| SNEVA DITCH (6800738) DWR↗ | 1881-10-15 | 5 | 36.0 | 0 | — |
| MCDONALD DITCH NO 145 (6800657) DWR↗ | 1881-11-01 | 4 | 35.8 | 0 | — |
| RIDGWAY DITCH (6800710) DWR↗ | 1882-06-01 | 3 | 32.0 | 0 | — |
| CORNERSTONE RESERVOIR NO4 (6803847) DWR↗ | 2003-12-29 | 2 | 30.4 | 49 | yes |
| TIERRA COLO DITCH (6800759) DWR↗ | 1909-05-03 | 1 | 30.0 | 0 | — |
| REED OVERMAN DITCH (6800703) DWR↗ | 1878-05-01 | 4 | 27.2 | 0 | — |
Recent inventory & legal-document changes
- 2026-10-17 — call released: 38507
- 2026-10-17 — call released: 39401
- 2026-10-17 — call released: 39109
- 2026-10-17 — call released: 39305
- 2026-10-13 — call released: 39683
- 2026-10-07 — call set: GALLOWAY DITCH (39683)
- 2026-10-07 — call released: 39623
- 2026-10-01 — call set: GALLOWAY DITCH (39623)
Water-court filings this month (division-wide)
5 applications in the 2026-09 resume for this basin's division — new rights, changes, augmentation plans — from the water clerk's statutory monthly notice (C.R.S. 37-92-302), the earliest public signal of a new claim. Filings are division-wide, not district-filtered: check the county column. Full resume PDF at the Judicial Branch →
Anyone affected may file a statement of opposition until 2026-11-30 (40 days left). C.R.S. 37-92-302(3): due by the last day of the second month following the filing month — computed, not legal advice; confirm with the water clerk.
All 5 filings, with excerpts
| Case | What it asks | County | Excerpt |
|---|---|---|---|
03CW70
|
plan for augmentation | — | Case No. 03CW70 including diversion rate, metering, accounting, reporting, calculation of depletions, and replacement of out of priority depletions. Cumulative simultaneous diversions from the two wells will be limited to 0.133 cfs. The Applicant seeks to amen… |
26CW3047
5905614 |
change of water right, plan for augmentation | — | Case No. 26CW3047 (Ref No. 03CW70) APPLICATION FOR CHANGE OF WATER RIGHT AND PLAN FOR AUGMENTATION. Name, address, and telephone number of Applicant: Riverland Lot Owners Association, c/o Toad Property Management, 318 Elk Avenue, Suite 10, Crested Butte, CO 81… |
26CW3048
|
reasonable diligence, make absolute | GUNNISON | Case No. 26CW3048 (Ref No. 20CW3030, 13CW3036, 05CW261, 96CW298) GUNNISON COUNTY. Slate River and/or East River. Application for Finding of Reasonable Diligence and to Make Conditional Water Rights Absolute in Part. Applicant: Whetstone Vista Association, Inc.… |
26CW3049
|
reasonable diligence | GUNNISON | Case No. 26CW3049 (Ref No. 20CW3026, 12CW151) APPLICATION FOR FINDING OF REASONABLE DILIGENCE OF MOUNTAIN COAL COMPANY, L.L.C., IN GUNNISON COUNTY, COLORADO. 1. Name, address, telephone number, and email address of Applicant: Mountain Coal Company, L.L.C. (the… |
26CW3050
|
change of water right | — | Case No. 26CW3050 (Ref No. 84CW118) Applicant: Fuzzy's Hideaway Trust c/o Louie Fesmire, PO Box 105, Guffey, CO 80820, 719-696-1556. Please direct all correspondence to Attorney for Applicant: LAW OF THE ROCKIES Kendall K. Burgemeister, Atty. Reg. #41593 525 N… |
Active substitute water supply plans in this district
Temporary State Engineer approvals to divert out of priority (37-92-308 / 37-90-137). A structure operating under one behaves differently under a call than its decreed rights alone suggest — the priority tables above don't know about these; this list does. Source: DWR’s active-SWSP register, refreshed nightly.
| Plan | Type | Status | Expires | Structure | Documents |
|---|---|---|---|---|---|
| CPW SOL TEAGUE DITCH | 37-92-308(5) PLANS LESS THAN 5 YEARS | Approved | 2026-03-31 | 6800741 | plan file |
Water quality
The water itself, in this district
Four registers, each on its own schedule: what USGS sensors read right now, where samples have been taken, which stretches the state lists as impaired, and how the tap water of the systems here stands with EPA. None is a DWR record; each links its own page.
Right now
Source Provisional telemetry · fetched 2026-10-21 · verify at USGS current conditions ↗
1 USGS sensor reports temperature, conductance, dissolved oxygen or turbidity from inside this district; provisional readings, never merged into the verified record.
| Site | Temp °C | Cond µS/cm | DO mg/L | Turb FNU | As of |
|---|---|---|---|---|---|
| UNCOMPAHGRE RIVER AT COLONA, CO | 8.6 | 592 | 9.4 | 10 | 2026-10-21 15:05 |
Where water has been sampled
Source Register of another agency · fetched 2026-10-08 · verify at Water Quality Portal ↗
The portal lists 956 sampling stations in this district's watershed (Uncompahgre 14020006), of which 64 reported a sample in the last 5 years on the state and tribal side (USGS activity is in the station count, not in that figure). Most active: Colorado River Watch (28), Colorado Dept. of Public Health & Environment-WQCD (19), USGS Colorado Water Science Center (17). Most-sampled groups: Inorganics, Major, Metals, Physical, Inorganics, Minor, Non-metals, Inorganics, Minor, Metals. Every station as a file ↗
Results themselves are not fetched here; USGS samples added after March 2024 may not be in the portal's legacy profiles yet.
Drinking water
Source Register of another agency · fetched 2026-10-07 · verify at EPA SDWIS ↗
5 community systems touch this district. None carries an open health-based violation on EPA's record. EPA sampled 0 of them for PFAS in 2023–25.
| System | Serves | EPA record | PFAS (UCMR 5) | Lead, latest 90th pct |
|---|---|---|---|---|
| OURAY CITY OF | 1,460 | 10 of 12 quarters with a violation | not sampled | 0.0013 mg/L |
| DALLAS CREEK WC | 1,059 | 4 of 12 quarters with a violation | not sampled | 0.002 mg/L |
| RIDGWAY TOWN OF | 1,000 | 12 of 12 quarters with a violation | not sampled | 0.0025 mg/L |
| ELK MEADOWS ESTATES | 230 | 11 of 12 quarters with a violation | not sampled | 0.0012 mg/L |
| DALLAS MEADOWS COMMUNITY ASSOC | 120 | 12 of 12 quarters with a violation | not sampled | 0.001 mg/L |
EPA's record carries violations and lead/copper percentiles; nitrate and disinfection by-product results are not in it. UCMR 5 samples are monitoring, not compliance, and the 2024 PFOA/PFOS limits equal its reporting limit, so any detection of those two is at or above them.
Impaired waters
Source Register of another agency · verify at EPA ATTAINS ↗
The state's 303(d) impaired-waters list has not been joined to this basin's own watershed boundary yet, so nothing is shown rather than a guess; the basins with a join carry the full list here. Why the join is geometry, not a name match.
Call cascade
If a call were placed at a given seniority, which structures in this basin would be out of priority, and how much of their decreed rate would be curtailed? Computed from this basin's cached decrees.
What this does and doesn't model. Seniority arithmetic only: every right junior to the call is treated as curtailed. It does not model reach applicability — structures downstream of the calling point are not administered by it — and it applies no futile-call judgment. Read it as “who is junior to this date, and by how much,” not as a prediction of what the Division Engineer would actually order.
Pick a calling right
Real decrees from this basin, ordered by administration number — that is, by actual seniority. The years will look out of order, and that is correct: an administration number encodes the adjudication date as well as the appropriation date, so a right appropriated in 1970 can be administered ahead of one from 1950. A senior call curtails almost everything; a junior one curtails almost nothing.
Or enter an administration number directly
DWR administration numbers encode appropriation and adjudication dates; lower is more senior.
This week's diagnostic
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System status
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Active river calls
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Hydrographs vs. historical envelope
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Anomaly flags
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Snowpack — no snow on the ground at 1 SNOTEL site — normal for the date; the snow year begins in October and typically peaks around April 6. Runoff outlook — Ridgway Reservoir Inflow: even odds of at least 14 kAF over 06-01 to 07-31 — 22% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — Uncompahgre R at Colona : even odds of at least 12 kAF over 06-01 to 07-31 — 16% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Full snow & runoff picture — charts, forecast history and how the forecasts have verified →
Sites, exceedance bands and sources
| SNOTEL site | Elev (ft) | SWE (in) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Idarado | 9780 | 0.1 | 0.0 | — | April 6 (14.4 in) |
Ridgway Reservoir Inflow — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 6 | 12 | 14 | 17 | 22 | 61 |
Uncompahgre R at Colona — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 7 | 10 | 12 | 17 | 24 | 74 |
Snow-water equivalent and medians (1991–2020) from NRCS SNOTEL; seasonal volume forecasts from the NRCS National Water and Climate Center. Sites and forecast points are assigned to the district whose boundary contains them — snowpack that feeds this district can also sit in a neighboring headwater district. Toggle the Snow chip on the map above to see the sites.
Topology cross-check: 16 parent disagreements (vs DWR's route framework — under review)
This flow network was built mechanically; DWR's Source Water Route Framework disagrees with it in the places below. Each row is a question a human reviewer has not yet answered — not an error verdict. Checked 22 streams, 6 agree. Know this water? Tell us →
| Stream | This site routes it to | DWR routes it to |
|---|---|---|
| Canyon Creek | the mainstem | Uncompahgre River |
| Red Mountain Creek | the mainstem | Uncompahgre River |
| Happy Canyon Creek | the mainstem | Uncompahgre River |
| Horsefly Creek | the mainstem | Uncompahgre River |
| Cottonwood Creek | the mainstem | East Fork Horsefly Creek |
| McKenzie Creek | the mainstem | Uncompahgre River |
| Cow Creek | the mainstem | Uncompahgre River |
| Fisher Creek | the mainstem | Uncompahgre River |