Hydrohistorian
Upper Colorado/Fraser Rivers
Upper Colorado/Fraser Rivers on the ground — the ditches, wells, reservoirs and gages of Water District 51 · 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 Fraser River is below normal for late September -- 51% of normal flow. 4 calls stand against it right now; the most senior right calling dates to 1883. DWR's statements do not settle whether 26 more calls reach it.
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 2026-09-30 (the newest reading on file), flows at the 31 ranked gages are running at a median 65% of their own long-term norm for this window — 25 below a typical year, 6 at or above. Driest relative to its record: WILLOW CREEK PUMP CANAL, ranking 1st lowest of 36 years.
How this comparison is made
Each gage's mean flow over the 3 days either side of 2026-09-30, 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 2026-10-11 20:30 from 84 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 84 gages with enough record, 4 are trending down and 3 up, and 8 carry a detected shift. The clearest is Ranch Creek Ditch near Winter Park, its annual mean flow changing +3.35 cfs per decade (+27.1% of its median annual flow) over 25 years (p=0.0083). The other 74 show no clear signal either way.
| Gage | Trend | Change / decade cfs · % of median annual flow | Significance | Years | Changepoint |
|---|---|---|---|---|---|
|
▸
Ranch Creek Ditch near Winter Park RANCRKCO |
↑ increasing | +3.35 cfs +27.1% | p=0.008 | 25 | ~1973 |
|
▸
Ranch Creek Ditch near Fraser RANDIFCO |
↑ increasing | +6.63 cfs +71.7% | p=0.009 | 18 | ~1954 |
|
▸
Colorado River near Grand Lake COLGRACO |
↓ decreasing | -6.08 cfs -7.7% | p=0.012 | 63 | ~1938 |
|
▸
Williams Fork near Parshall WILPARCO |
↓ decreasing | -4.36 cfs -3.5% | p=0.014 | 111 | ~1952 |
|
▸
Colorado River near Granby COLNGBCO |
↓ decreasing | -52.12 cfs -17.8% | p=0.024 | 21 | — |
|
▸
Colorado River below Lake Granby COLGBYCO |
↑ increasing | +10.40 cfs +22.3% | p=0.024 | 13 | — |
|
▸
St. Louis Creek near Fraser SLOFRACO |
↓ decreasing | -1.47 cfs -6.5% | p=0.048 | 91 | ~1958 |
|
▸
Vasquez Creek at Winter Park VASWINCO |
no clear trend | +0.72 cfs +5.7% | p=0.088 | 91 | ~1992 |
|
▸
Fraser River at Winter Park FRAWINCO |
no clear trend | -1.76 cfs -9.3% | p=0.143 | 115 | ~1936 |
|
▸
Ranch Creek near Fraser RANFRACO |
no clear trend | -0.45 cfs -3.3% | p=0.324 | 91 | ~1952 |
74 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. 36 gage(s) and 276 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1976. 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 | 3 | 0 |
| 1910s | 4 | 0 |
| 1920s | 2 | 0 |
| 1930s | 13 | 0 |
| 1940s | 16 | 0 |
| 1950s | 26 | 0 |
| 1960s | 23 | 0 |
| 1970s | 22 | 50 |
| 1980s | 22 | 250 |
| 1990s | 23 | 300 |
| 2000s | 28 | 262 |
| 2010s | 32 | 253 |
| 2020s | 36 | 276 |
Mass-balance (network closure) trend
Structure divrec-history backfill coverage as of the last check: 10% of 2609 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 (1950–2026)
Mass-balance kinks computed for every summer month back to 1950 (2481 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.
- RANCH CREEK NEAR TABERNASH, CO.: reach shifted from -129 cfs to -138 cfs summer mean (more losing, p=0.029, 11 yr) [mountain crystalline canyon: minimal groundwater storage -- large or shifting unaccounted losses here are more consistent with data/measurement issues or unmodeled plumbing than with aquifer exchange]
- WILLIAMS FORK BELOW WILLIAMS FORK RESERVOIR, CO: reach shifted from +137 cfs to -146 cfs summer mean (more losing, p=0.000, 73 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=-0.67) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
- WILLOW CREEK BELOW WILLOW CREEK RESERVOIR: reach shifted from -36 cfs to -133 cfs summer mean (more losing, p=0.003, 68 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: 74 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.
Reservoirs now has its own tab: 126 reservoir(s), end-of-year storage back to 1975, click-to-chart histories.
Cross-gage pattern fingerprint
Over the 93-year window with full coverage (1934–2026), the dominant shared pattern across 3 gage(s) explains 85% 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 2026-09-30)
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.
- HIGHLAND AUGMENTATION PO (diversion): +6.9 cfs (33% of that reach's correction)
- CURTIS NO 1 DITCH (diversion): +6.9 cfs (33% of that reach's correction)
- VULGAMOTT DITCH NO 2 (diversion): +6.9 cfs (33% of that reach's correction)
- VAN ELLS SPRING & PIPELINE NO 3 (return): +1.8 cfs (3% of that reach's correction)
- VAN ELLS SPRING & PIPELINE NO 1 (return): +1.8 cfs (3% of that reach's correction)
- VAN ELLS SPRING & PIPELINE NO 2 (return): +1.8 cfs (3% of that reach's correction)
- HUGGINS DITCH (diversion): +1.8 cfs (3% of that reach's correction)
- HUGGINS DITCH NO 2 (diversion): +1.8 cfs (3% of that reach's correction)
- SELAK LARRABEE DITCH (diversion): +1.8 cfs (3% of that reach's correction)
- MILLER INT - SELAK LARABEE (diversion): +1.8 cfs (3% of that reach's correction)
Data provenance & quality
Where these numbers come from and how far they can be trusted. Grade D (2/6 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 11 day(s) old (target 7) |
| diversion record | stale | newest diversion record is 711 day(s) old (DWR publishes ~1 year in arrears) |
| structure coverage | sparse | 10% of schematic structures have data |
Independent check: PASS — 100.0000% agreement across 103,104 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 — 99.81% day-level agreement with USGS's own published records for the same gages, across 61 co-listed station(s) and 601,272 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.
84 gage(s) / 760,405 daily values (1904-10-01–2026-09-30); 628 structure(s) with diversion records; 2208 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 ↗
1,051 water-level measurements across 74 monitored well(s) — 65 alluvial, 0 bedrock — plus 19 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.
RANCH CREEK NEAR TABERNASH, CO.: 1 alluvial well(s) nearby; pooled water table — ft (1996–2011, no_trend, p=0.7105)
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.
48% are constructed wells; 6% 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
23 located water-supply permits with an issue date, 1972 to 2026; half of them had been issued by 2006, and the busiest year was 2026 with 4. A permit is not a well, and the year is the date the paper was issued, not a drilling date. The 33 above counts every permit on file here; 10 of them have no usable location or no issue date and are not in this chart.
water-supply permits issued that year
The counts by year, as a table
| Year | Issued | Monitoring holes | Water-supply | Issued through that year |
|---|---|---|---|---|
| 1972 | 1 | 0 | 1 | 1 |
| 1974 | 1 | 0 | 1 | 2 |
| 1985 | 1 | 0 | 1 | 3 |
| 1992 | 1 | 0 | 1 | 4 |
| 1994 | 1 | 0 | 1 | 5 |
| 1997 | 1 | 0 | 1 | 6 |
| 1998 | 1 | 0 | 1 | 7 |
| 1999 | 1 | 0 | 1 | 8 |
| 2000 | 1 | 0 | 1 | 9 |
| 2002 | 1 | 0 | 1 | 10 |
| 2004 | 1 | 0 | 1 | 11 |
| 2006 | 1 | 0 | 1 | 12 |
| 2014 | 1 | 0 | 1 | 13 |
| 2018 | 2 | 0 | 2 | 15 |
| 2021 | 1 | 0 | 1 | 16 |
| 2022 | 2 | 0 | 2 | 18 |
| 2024 | 1 | 0 | 1 | 19 |
| 2026 | 4 | 0 | 4 | 23 |
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
2 PLSS townships here where at least 5 water-supply permits naming the same aquifer filed a depth (12 permits in all). Each column is one township, six miles square, on one scale to 500 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. 1 of these townships straddles a district line and is filed here because most of its permits are.
6
6 · 80% here
unnamed 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 |
|---|---|---|---|---|---|---|
| T1N R76W 6th PM | 100% | unnamed | 6 | 128 / 265 / 492 | — | — |
| T3N R76W 6th PM | 80% | unnamed | 6 | 66 / 120 / 200 | 48 / 78 / 96 | 60 / 118 / 204 |
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 ↗
126 reservoir(s) with 11,152 storage measurement(s), 1975–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 569,595 AF across 33 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) | |
|---|---|---|---|---|---|
| ▸ CBT GRANBY RESERVOIR (5104055) | 462,484 | 2024-10-31 | — | — | dossier → |
| ▸ WILLIAMS FORK RESERVOIR (5103709) | 81,431 | 2024-10-31 | — | — | dossier → |
| ▸ CBT SHADOW MOUNTAIN LAKE (5103695) | 16,969 | 2024-10-31 | — | — | dossier → |
| ▸ CBT WILLOW CREEK RESERVOIR (5103710) | 6,970 | 2024-10-31 | — | — | dossier → |
| ▸ EAST BRANCH RESERVOIR (5103715) | 1,738 | 2016-10-31 | — | — | dossier → |
| ▸ MEADOW CREEK RESERVOIR (5103686) | 611 | 2024-10-31 | — | — | dossier → |
| ▸ SYLVAN RESERVOIR (5103701) | 300 | 2024-09-10 | — | — | dossier → |
| ▸ JACK ORR RESERVOIR (5104009) | 245 | 1994-10-31 | — | — | dossier → |
Snow and runoff
Source Independent agency measurement · fetched 2026-10-13 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record
Snow-water equivalent, WY2027
| SNOTEL site | Elev (ft) | SWE (in) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Berthoud Summit | 11300 | 0.1 | 0.0 | — | May 3 (23.2 in) |
| Fool Creek | 11130 | 0.2 | — | — | — |
| High Lonesome | 10630 | 0.2 | — | — | — |
| Jones Pass | 10430 | 0.0 | 0.0 | — | April 27 (16.8 in) |
| Lake Irene | 10680 | 0.0 | 0.3 | — | April 26 (25.4 in) |
| Middle Fork Camp | 8960 | 0.2 | 0.0 | — | April 4 (11.5 in) |
| Phantom Valley | 9030 | 0.0 | 0.0 | — | March 30 (10.4 in) |
| Stillwater Creek | 8760 | 0.0 | — | — | — |
| Willow Creek Pass | 9520 | 0.6 | 0.0 | — | May 3 (16.4 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 (1979–2026)
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 6 of the last 48 winters the snow never came — the pack peaked below 80% of its median. In 0 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, 1987, 2002, 2004, 2012, 2026.
Computed by this site from 9 SNOTEL sites’ full daily records (NRCS AWDB, back to 1979). 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 — Lake Granby Inflow
NRCS's final issue (2026-06-01) calls it even odds that at least 49 kAF arrives over 06-01 to 07-31 — 33% of a normal season; almost certainly at least 27, probably not more than 71. Our own record at this gage shows 13 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 64 replayed seasons (11% typical miss unadjusted vs 13% 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 |
|---|---|---|---|---|---|---|
| 27 | 40 | 49 | 58 | 71 | 149 | 13 |
How good are these forecasts here? (1950–2026)
Grading every April issue against what the river then delivered, measured against NRCS’s naturalized volumes (this point forecasts the river as it would run without upstream storage and diversions — which no gage measures) — 76 seasons: the median miss of the 50% forecast is 12%, with a low bias of 1%, and the observed volume landed inside the stated 10–90% band 82% 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 NRCS’s own naturalized monthly volumes; years missing any month 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 (1979–2026)
Across 48 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 83% 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 0.9).
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 — Willow Ck Reservoir Inflow
NRCS's final issue (2026-06-01) calls it even odds that at least 7 kAF arrives over 06-01 to 07-31 — 36% of a normal season; almost certainly at least 2, probably not more than 15. Our own record at this gage shows 1 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 64 replayed seasons (19% typical miss unadjusted vs 19% 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 |
|---|---|---|---|---|---|---|
| 2 | 5 | 7 | 10 | 15 | 19 | 1 |
How good are these forecasts here? (1950–2026)
Grading every April issue against what the river then delivered, measured against NRCS’s naturalized volumes (this point forecasts the river as it would run without upstream storage and diversions — which no gage measures) — 76 seasons: the median miss of the 50% forecast is 20%, with a low bias of 7%, and the observed volume landed inside the stated 10–90% band 76% 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 NRCS’s own naturalized monthly volumes; years missing any month 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 (1979–2026)
Across 48 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 71% 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 1.5).
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 — Williams Fk bl Williams Fk Reservoir
NRCS's final issue (2026-06-01) calls it even odds that at least 10 kAF arrives over 06-01 to 07-31 — 18% of a normal season; almost certainly at least 5, probably not more than 20. Our own record at this gage shows 21 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 32 replayed seasons (15% typical miss unadjusted vs 21% 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 |
|---|---|---|---|---|---|---|
| 5 | 8 | 10 | 14 | 20 | 59 | 21 |
How good are these forecasts here? (1993–2026)
Grading every April issue against what the river then delivered, measured against NRCS’s naturalized volumes (this point forecasts the river as it would run without upstream storage and diversions — which no gage measures) — 33 seasons: the median miss of the 50% forecast is 16%, with a low bias of 7%, and the observed volume landed inside the stated 10–90% band 73% 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 NRCS’s own naturalized monthly volumes; years missing any month 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 (1979–2026)
Across 48 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 80% 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 1.1).
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 2026-10-06 · verify at U.S. Drought Monitor ↗
Right now
This is the 59th-driest week 39 in 116 years of record at FRASER RIVER AT WINTER PARK, CO. (as of 2026-09-21; this week’s flow sits at the 51st 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, Grand County is 54% in D4 exceptional drought (2026-10-06). The law agrees: the most senior active call leaves 99% of this district’s decreed flow rights junior to the calling right this week.
Every year since 1910, week by week
Each thin row is a year at FRASER RIVER AT WINTER PARK, 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 32 weeks recorded so far, 2026’s weekly trace most resembles 2012 (mean gap 17.3 percentile points; next closest 1966 (17.9), 2004 (18.1)). 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 Grand county — 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 1990 — 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 (152 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.
1383–1999: this river before anyone measured it
Tree rings record wet and dry years centuries before the first gage. This is the published reconstruction of annual flow at Fraser River at confluence with Colorado R. — 617 years, with its uncertainty band drawn, not implied — and the green line is the measured record at the same gage, water-year totals from DWR’s daily data, carrying the story through 2022. A reconstruction is an estimate, not a measurement: it answers “is this decade unusual in four centuries?”, and nothing in this site’s statistics uses it.
Why the two lines disagree on purpose: the trees were calibrated against naturalized flow — upstream diversions and storage added back — while the gage measures what the ditches left in the river. So the measured line running below the reconstruction is not an error; the gap is, roughly, human use. And because the reconstruction was fit to gage-era data, the overlap shows how well trees track the river (the authors report the models explain 63–76% of gage variance) — it is a calibration, not an independent test.
Woodhouse, C.A. and J.J. Lukas (2006), Multi-century tree-ring reconstructions of Colorado streamflow for water resource planning, Climatic Change 78; data via NOAA NCEI World Data Service for Paleoclimatology / TreeFlow. Source data ↗
This basin’s droughts, by its own record
| Drought | Span | Weeks | Trough percentile | Flows recovered | Water table back |
|---|---|---|---|---|---|
| the 2018 drought | 2019-04-01 → 2019-09-02 | 22 | 26th (2019-06-17) | 4 weeks | — |
| the 2012-13 drought | 2013-04-15 → 2013-09-09 | 21 | 26th (2013-05-06) | 4 weeks | — |
| unnamed dry spell | 2008-02-18 → 2008-08-18 | 26 | 24th (2008-04-14) | 57 weeks | 1 yr (5 wells) |
| unnamed dry spell | 2004-08-23 → 2005-09-05 | 54 | 17th (2005-03-21) | 95 weeks | — |
| the 2002 drought | 2002-01-14 → 2003-06-09 | 73 | 16th (2002-06-24) | 29 weeks | — |
| the 2002 drought | 2000-12-11 → 2001-09-03 | 38 | 14th (2001-03-26) | 121 weeks | — |
| unnamed dry spell | 1998-03-16 → 1998-08-17 | 22 | 19th (1998-04-27) | 1 week | 6 yr (6 wells) |
| unnamed dry spell | 1995-01-23 → 1995-07-17 | 25 | 24th (1995-02-20) | 0 weeks | — |
| unnamed dry spell | 1991-03-18 → 1991-09-09 | 25 | 23rd (1991-04-29) | 6 weeks | — |
| unnamed dry spell | 1989-01-09 → 1990-11-12 | 96 | 10th (1990-04-09) | 49 weeks | — |
| unnamed dry spell | 1988-03-07 → 1988-09-05 | 26 | 16th (1988-04-18) | 163 weeks | — |
| unnamed dry spell | 1985-10-28 → 1986-09-22 | 47 | 11th (1986-04-21) | 3 weeks | not yet (16 of 26 wells still below) |
| unnamed dry spell | 1983-03-07 → 1983-08-15 | 23 | 21st (1983-05-16) | 1 week | — |
| the 1981 drought | 1980-11-24 → 1982-12-13 | 107 | 10th (1981-03-16) | 36 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 (3,038 rights across 117 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is -0.35 — this basin tended to claim water in dry times, under scarcity pressure. 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 ↗
16 systems touch this district (16 community systems reporting 26,758 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 |
|---|---|---|---|
| WINTER PARK WSD | 6,635 | Surface water | 100% of its area |
| GRAND COUNTY WATER NO 1 | 5,400 | Surface water | 100% of its area |
| WINTER PARK RANCH WSD | 3,250 | Groundwater | 100% of its area |
| GRANBY TOWN OF SOUTH SERVICE AREA | 2,300 | Groundwater under the influence of surface water | 100% of its area |
| FRASER TOWN OF | 2,150 | Groundwater | 100% of its area |
| GRAND LAKE TOWN OF | 2,035 | Groundwater | 100% of its area |
| GRANBY TOWN OF NORTH SERVICE AREA | 2,025 | Surface water | 100% of its area |
| HOT SULPHUR SPRINGS TOWN OF | 687 | Surface water | 100% of its area |
and 8 more; the full directory filters by district.
Instream-flow rights held by the state
Source Register of another agency · fetched 2026-10-11 · verify at CWCB instream flow program ↗
173 reaches over 492.7 miles and 9 natural lake levels, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →
- Colorado River, 14.7 mi: 90 (1/1 - 12/31) cfs (appropriated 1980, 80CW0447) · dossier
- Fraser River, 13.2 mi: 30 (5/15 - 9/15), 19 (9/16 - 5/14) cfs (appropriated 1990, 90CW0308) · dossier
- Willow Creek, 11.0 mi: 12 (1/1 - 12/31) cfs (appropriated 1978, 78W3774) · dossier
- Beaver Creek, 10.0 mi: 1.5 (1/1 - 12/31) cfs (appropriated 1986, 86CW0206) · dossier
- Keyser Creek, 9.5 mi: 3 (10/1 - 4/30), 6 (5/1 - 9/30) cfs (appropriated 1979, 79CW0184) · dossier
- Williams Fork, 9.0 mi: 19 (10/1 - 4/30), 38 (5/1 - 9/30) cfs (appropriated 1979, 79CW0185) · dossier
and 176 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 1864-06-01 to 2024-11-30. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 30% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 332 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: 3491 across 2208 structure(s); 375 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 1988–2025, administration on this district has been tightening: 3 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 (38 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 | 365 | 184 | 1884-04-07 |
| 2015 | 365 | 256 | 1885-07-28 |
| 2016 | 366 | 237 | 1884-04-26 |
| 2017 | 365 | 330 | 1884-05-01 |
| 2018 | 365 | 290 | 1884-03-02 |
| 2019 | 365 | 165 | 1886-08-09 |
| 2020 | 366 | 221 | 1883-03-30 |
| 2021 | 365 | 218 | 1883-03-15 |
| 2022 | 365 | 201 | 1885-06-01 |
| 2023 | 365 | 120 | 1885-07-28 |
| 2024 | 366 | 164 | 1886-08-09 |
| 2025 | 365 | 232 | 1885-06-16 |
Why diversions stopped — call-based explanations
Sustained diversion stops matched to senior administrative calls.
- AXEL DITCH (5100513) DWR↗ stopped 2024-08-03 (64+ days) — call at CAMP BIRD DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BERG NO 1 DITCH (UPSTREAM) (5100525) DWR↗ stopped 2024-07-19 (67+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BERG NO 2 DITCH (DOWNSTREAM) (5100526) DWR↗ stopped 2024-07-19 (67+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BRINKER DITCH (5100539) DWR↗ stopped 2024-07-14 (45+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- ALEXANDER DITCH (5100503) DWR↗ stopped 2024-07-13 (34+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BUEHLER NO 2 DITCH (5100542) DWR↗ stopped 2024-07-10 (76+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BUEHLER NO 3 DITCH (5100543) DWR↗ stopped 2024-07-10 (76+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BUEHLER NO 4 DITCH (5100544) DWR↗ stopped 2024-07-10 (76+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BECK DITCH (5100521) DWR↗ stopped 2024-07-08 (72+ days) — call at ATKINSON DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BARKER NO 1 DITCH (5100516) DWR↗ stopped 2023-10-30 (214+ days) — call at MOCKING BIRD 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 |
|---|---|---|---|
| CBT GRANBY PUMP CANAL (5100678) DWR↗ | 1935-08-01 | 30.2% / 0.0% | 30.2% / 0.0% |
| MOFFAT WATER TUNNEL (5104655) DWR↗ | 1921-07-04 | 30.2% / 0.0% | 30.2% / 0.0% |
| WINDY GAP PUMP PIPELINE CANAL (5104700) DWR↗ | 1967-06-22 | 5.4% / 0.0% | 4.9% / 0.0% |
| CBT ALVA B ADAMS TUNNEL (5104634) DWR↗ | 1935-08-01 | 30.2% / 0.0% | 30.2% / 0.0% |
| GRAND RIVER DITCH (5104601) DWR↗ | 1890-09-01 | 69.2% / 0.0% | 69.2% / 0.0% |
| CBT WILLOW CREEK FEEDER (5100958) DWR↗ | 1935-08-01 | 30.2% / 0.0% | 30.2% / 0.0% |
| WILLIAMS FORK POWER CONDUIT (5101237) DWR↗ | 1933-10-15 | 30.2% / 0.0% | 5.4% / 0.0% |
| FRASER RIVER DIVERSION PROJECT - FRASER (5100639) DWR↗ | 1921-07-04 | 30.2% / 0.0% | 2.8% / 0.0% |
| WILLIAMS FORK TUNNEL (5104603) DWR↗ | 1921-07-04 | 30.2% / 0.0% | 30.2% / 0.0% |
| BIG LAKE DITCH (5100529) DWR↗ | 1903-02-06 | 67.8% / 0.0% | 2.8% / 0.0% |
| FRASER RIVER DIVERSION PROJECT - VASQUEZ (5101310) DWR↗ | 1921-07-04 | 30.2% / 0.0% | 2.8% / 0.0% |
| RED TOP VALLEY DITCH (5100848) DWR↗ | 1901-11-10 | 67.8% / 0.0% | 2.8% / 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 ~1976 — idleness that begins before then may be unreported use, not nonuse (flagged † below).
- GRAND LAKE PIPELINE (5100679) DWR↗ (1945-03-15, 6.0 cfs decreed): last active 1976 — 35 years idle
- HOLZWARTH DITCH NO 3 (5100713) DWR↗ (1920-06-01, 1.0 cfs decreed): last active 1976 — 35 years idle
- KIMSEY NO 1 DITCH (5100762) DWR↗ (1891-05-01, 1.6 cfs decreed): last active 1976 — 35 years idle
- MILLS GULCH DITCH (5100797) DWR↗ (1864-06-01, 0.5 cfs decreed): last active 1976 — 35 years idle
- WOOD PIPELINE (5100969) DWR↗ (1931-01-01, 0.0 cfs decreed): last active 1976 — 35 years idle
- BUNTE RESERVOIR (5103646) DWR↗ (1911-04-18, 0.0 cfs decreed): last active 1976 — 35 years idle
- F W LINKE RESERVOIR (5103659) DWR↗ (1948-05-13, 0.0 cfs decreed): last active 1976 — 35 years idle
- F W LINKE NO 2 RESERVOIR (5103660) DWR↗ (1950-10-11, 0.0 cfs decreed): last active 1976 — 35 years idle
- HANKINSON RESERVOIR (5103665) DWR↗ (1949-01-27, 0.0 cfs decreed): last active 1976 — 35 years idle
- LINKE RESERVOIR (5103680) DWR↗ (1910-10-20, 0.0 cfs decreed): last active 1976 — 35 years idle
Compliance screens (332 advisory flags)
Screened 442 of 2208 structures with rights (526 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.
- CBT WILLOW CREEK FEEDER (5100958) DWR↗: Observed p99 daily rate 444.0 cfs (max 551.0) exceeds total decreed absolute 400.0 cfs across 36486 recorded day(s).
- KINNEY BARRIGER DITCH (5100763) DWR↗: Observed p99 daily rate 96.1 cfs (max 114.0) exceeds total decreed absolute 65.0 cfs across 12282 recorded day(s).
- RED TOP VALLEY DITCH - STILLWATER CREEK (5101315) DWR↗: Observed p99 daily rate 92.0 cfs (max 120.0) exceeds total decreed absolute 12.0 cfs across 3495 recorded day(s).
- FRASER RIVER DIVERSION PROJECT - LITTLE (5101265) DWR↗: Observed p99 daily rate 60.0 cfs (max 107.0) exceeds total decreed absolute 0.7 cfs across 8394 recorded day(s).
- BUNTE HIGHLINE DITCH (5100546) DWR↗: Observed p99 daily rate 50.0 cfs (max 54.0) exceeds total decreed absolute 45.0 cfs across 9915 recorded day(s).
- SOPHRONIA DAY DITCH (5100893) DWR↗: Observed p99 daily rate 40.5 cfs (max 48.2) exceeds total decreed absolute 24.1 cfs across 8932 recorded day(s).
- OSTRANDER DITCH (5100826) DWR↗: Observed p99 daily rate 31.0 cfs (max 32.1) exceeds total decreed absolute 16.0 cfs across 7031 recorded day(s).
- HAMILTON-CABIN CREEK EXTENSION (5101250) DWR↗: Observed p99 daily rate 29.0 cfs (max 63.0) exceeds total decreed absolute 25.0 cfs across 24685 recorded day(s).
- MUSGRAVE DITCH (5100810) DWR↗: Observed p99 daily rate 27.8 cfs (max 50.5) exceeds total decreed absolute 25.0 cfs across 17386 recorded day(s).
- SHERIFF DITCH (COLORADO RIVER) (5100883) DWR↗: Observed p99 daily rate 25.4 cfs (max 25.4) exceeds total decreed absolute 18.8 cfs across 6849 recorded day(s).
Seniority (top structures by decreed rate)
| Structure | Senior priority date | Rights | Decreed abs (cfs) | Decreed abs (AF) | Conditional? |
|---|---|---|---|---|---|
| CBT GRANBY PUMP CANAL (5100678) DWR↗ | 1935-08-01 | 1 | 1100.0 | 0 | — |
| MOFFAT WATER TUNNEL (5104655) DWR↗ | 1921-07-04 | 1 | 928.0 | 0 | yes |
| WINDY GAP PUMP PIPELINE CANAL (5104700) DWR↗ | 1967-06-22 | 3 | 600.0 | 0 | — |
| CBT ALVA B ADAMS TUNNEL (5104634) DWR↗ | 1935-08-01 | 1 | 550.0 | 0 | — |
| GRAND RIVER DITCH (5104601) DWR↗ | 1890-09-01 | 1 | 524.6 | 0 | — |
| CBT WILLOW CREEK FEEDER (5100958) DWR↗ | 1935-08-01 | 1 | 400.0 | 0 | — |
| WILLIAMS FORK POWER CONDUIT (5101237) DWR↗ | 1933-10-15 | 3 | 311.0 | 0 | yes |
| FRASER RIVER DIVERSION PROJECT - FRASER (5100639) DWR↗ | 1921-07-04 | 6 | 275.7 | 0 | yes |
| WILLIAMS FORK TUNNEL (5104603) DWR↗ | 1921-07-04 | 1 | 254.0 | 0 | yes |
| BIG LAKE DITCH (5100529) DWR↗ | 1903-02-06 | 3 | 231.0 | 0 | yes |
| FRASER RIVER DIVERSION PROJECT - VASQUEZ (5101310) DWR↗ | 1921-07-04 | 6 | 175.0 | 0 | yes |
| RED TOP VALLEY DITCH (5100848) DWR↗ | 1901-11-10 | 2 | 150.0 | 0 | yes |
| MIN FLOW COLORADO RIVER TROUBLESOME-BLUE (5102036) DWR↗ | 1980-07-08 | 1 | 150.0 | 0 | — |
| MIN FLOW COLORADO RIVER WILLIAMS FK-TROU (5102037) DWR↗ | 1980-07-08 | 1 | 135.0 | 0 | — |
| WILLIAMS FORK DIVERSION PROJECT - SOUTH (5101279) DWR↗ | 1921-07-04 | 3 | 115.0 | 0 | yes |
Recent inventory & legal-document changes
- 2026-10-09 — call released: 39534
- 2026-10-08 — call set: GRAND VALLEY CANAL (39690)
- 2026-10-08 — call released: 36734
- 2026-10-08 — call released: 38588
- 2026-10-08 — call released: 39264
- 2026-10-07 — call set: CORNELL DITCH (39681)
- 2026-10-07 — call set: MOCKING BIRD DITCH (39686)
- 2026-10-07 — call released: 39636
Water-court filings this month (division-wide)
9 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 (48 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 9 filings, with excerpts
| Case | What it asks | County | Excerpt |
|---|---|---|---|
26CW3086
|
change of water right | GRAND | 26CW3086 GRAND COUNTY -RECTOR FAMILY LIMITED LIABILITY LIMITED PARTNERSHIP, MIKE RECTOR, GENERAL PARTNER (5 Inverness Dr. East, Englewood, CO 80112; mhr@rimop.com; 303-570-5174), c/o Valissa Tsoucaris, Esq., Tsoucaris Law, LLC, 3000 Holly Street, Denver, CO 80… |
26CW3097
|
reasonable diligence | PITKIN | 26CW3097 PITKIN COUNTY, COLORADO; COLORADO RIVER OR ITS TRIBUTARIES. WOODY CREEK COMMUNE 1, LLC; WOODY CREEK COMMUNE 2, LLC; WOODY CREEK COMMUNE 3, LLC; and WOODY CREEK COMMUNE 4, LLC, Colorado limited liability companies; c/o Danielle L. Van Arsdale, Esq., Wo… |
26CW3098
|
reasonable diligence | GRAND | 26CW3098 GRAND COUNTY. Ritschard Springs Association, P.O. Box 1594, Kremmling, CO 80459, c/o Kaitlin Randall and Kent Whitmer, JVAM PLLC, PO Box 878, Glenwood Springs, CO 81602, (970) 922 -2122. APPLICATION FOR FINDING OF SEPTEMBER 2026 RESUME WATER DIVISION … |
26CW3099
|
reasonable diligence | GARFIELD | 26CW3099 GARFIELD COUNTY, COLORADO, A SPRING TRIBUTARY TO THE COLORADO RIVER . S Bar Lazy S Enterprises LLC, P.O. Box 809, Silt, Colorado 81652. Please direct all correspondence to Jeffrey J. Conklin and Danielle T. Skinner of Karp Neu Hanlon, P.C., P.O. Drawe… |
26CW3100
|
reasonable diligence | PITKIN | 26CW3100 PITKIN COUNTY – ROARING FORK RIVER AND ITS TRIBUTARIES. RUSSELL WIGHT c/o Paul L. Noto and John Sittler, Patrick, Miller & Noto, P.C., 229 Midland Ave., Basalt, CO 81621 (970) 920-1030. APPLICATION FOR FINDINGS OF REASONABLE DILIGENCE. First Claim: Wi… |
26CW3101
|
reasonable diligence, make absolute | GARFIELD | 26CW3101 GARFIELD COUNTY, CANYON CRK, COLORADO RIVER. App for Reasonable Diligence and To Make Absolute. Ross Jeffery c/o Sherry Caloia, PO Box 443, Glenwood Sprgs 81602. Name: Ross Hydro, decreed in 20CW002 on 10/11/2020. Desc: 1 or more pipelines in NW¼ NE¼ … |
26CW3102
|
— | GRAND | 26CW3102 GRAND COUNTY . Moose Ridge Association, c/o Robin Tieman, President, 4075 Nassau Pl., Boulder, CO 80301. Applicant is represented by Kaitlin Randall and Kent Whitmer, JVAM PLLC, PO Box 878, Glenwood Springs, CO 81602, (970) 922 - 2122. APPLICATION FOR… |
26CW3105
|
reasonable diligence | PITKIN | 26CW3105 PITKIN COUNTY, COLORADO. WATER RIGHT TRIBUTARY TO THE ROARING FORK RIVER. Application for Findings of Reasonable Diligence. Aspen Skiing Company, LLC, c/o Kylie J. Crandall, Esq., Mark E. Hamilton, Esq., HOLLAND & HART LLP, 600 E. Main St., Suite 104,… |
26CW3107
|
reasonable diligence | EAGLE | 26CW3107 EAGLE COUNTY, COLORADO, GROUNDWATER TRIBUTARY TO LAKE CREEK, TRIBUTARY TO THE EAGLE RIVER, TRIBUTARY TO THE COLORADO RIVER. WLC1003 LLC, 1003 Lake Creek Road, Edwards, Colorado 81632. Please direct all correspondence to Michael J. Sawyer and Erika S. … |
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 |
|---|---|---|---|---|---|
| FRASER, TOWN OF - MARYVALE WELLS | 37-92-308(7) PLAN EMERGENCY | Approved | 2026-07-08 | — | plan file |
| COLD SPRINGS RANCH & GREENHOUSE | 37-92-308(5) PLANS LESS THAN 5 YEARS | Approved | 2027-07-31 | — | plan file |
| KATTENBURG PIT | 37-90-137(11) GRAVEL PIT PLAN | Approved | — | — | plan file |
| BYERS PEAK PROPERTIES, LLC | 37-92-308(5) PLANS LESS THAN 5 YEARS | Pending | — | — | plan file |
| RANCHES AT DEVILS THUMB 23CW3209 | 37-92-308(4) PLAN PENDING COURT APPLICATION | Additional Info Needed | — | — | plan file |
| WH CABINS LLC | 37-92-308(4) PLAN PENDING COURT APPLICATION | Finished Plan | — | — | 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 2026-10-13 · verify at USGS current conditions ↗
8 USGS sensors report 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 |
|---|---|---|---|---|---|
| FRASER RIVER AT MOFFAT TUNNEL AT WINTER PARK, CO ↗ | 7.0 | 126 | 2 | 2026-10-13 21:15 | |
| FRASER RIVER AT TABERNASH, CO | 12.7 | 143 | 2026-10-13 20:15 | ||
| FRASER RIVER AT UPPER STA, NEAR WINTER PARK, CO. | 6.5 | 141 | 2026-10-13 20:15 | ||
| FRASER RIVER AT WINTER PARK, CO. | 8.9 | 145 | 2026-10-13 21:00 | ||
| FRASER RIVER BLW CROOKED CR AT TABERNASH CO | 12.5 | 2026-10-13 20:15 | |||
| FRASER RIVER BLW MOFFAT TUNNEL AT WINTER PARK, CO ↗ | 7.2 | 136 | 2 | 2026-10-13 21:15 | |
| GRAND LAKE OUTLET BLW CHIPMUNK LN AT GRAND LK, CO ↗ | 14.0 | 74 | 1 | 2026-10-13 21:10 | |
| ST. LOUIS CREEK NEAR FRASER, CO. | 8.1 | 107 | 2026-10-13 21:00 |
Where water has been sampled
Source Register of another agency · fetched 2026-10-08 · verify at Water Quality Portal ↗
The portal lists 1,156 sampling stations in this district's watershed (Colorado Headwaters 14010001), of which 123 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: USGS Colorado Water Science Center (58), Colorado Dept. of Public Health & Environment-WQCD (53), Colorado River Watch (10). Most-sampled groups: Physical, Inorganics, Major, Non-metals, Nutrient, 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 ↗
16 community systems touch this district. None carries an open health-based violation on EPA's record. EPA sampled 2 of them for PFAS in 2023–25; none had PFOA or PFOS at or above the 2024 limit.
| System | Serves | EPA record | PFAS (UCMR 5) | Lead, latest 90th pct |
|---|---|---|---|---|
| WINTER PARK WSD | 6,635 | clean, last 12 quarters | none detected | 0.003 mg/L |
| GRAND COUNTY WATER NO 1 | 5,400 | 12 of 12 quarters with a violation | 1 detected, under the limits | 0.001 mg/L |
| WINTER PARK RANCH WSD | 3,250 | clean, last 12 quarters | not sampled | 0.002 mg/L |
| GRANBY TOWN OF SOUTH SERVICE AREA | 2,300 | 1 of 12 quarters with a violation | not sampled | 0.002 mg/L |
| FRASER TOWN OF | 2,150 | 1 of 12 quarters with a violation | not sampled | 0.0068 mg/L |
| GRAND LAKE TOWN OF | 2,035 | clean, last 12 quarters | not sampled | 0.0018 mg/L |
| GRANBY TOWN OF NORTH SERVICE AREA | 2,025 | 4 of 12 quarters with a violation | not sampled | 0.008 mg/L |
| HOT SULPHUR SPRINGS TOWN OF | 687 | 2 of 12 quarters with a violation | not sampled | 0.002 mg/L |
| TABERNASH MEADOWS WSD | 564 | clean, last 12 quarters | not sampled | 0.0 mg/L |
| COLUMBINE LAKE WSD | 428 | clean, last 12 quarters | not sampled | 0.0043 mg/L |
and 6 more; the full directory filters by district.
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 — 9 SNOTEL sites report here. Runoff outlook — Lake Granby Inflow : even odds of at least 49 kAF over 06-01 to 07-31 — 33% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — Willow Ck Reservoir Inflow : even odds of at least 7 kAF over 06-01 to 07-31 — 36% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — Williams Fk bl Williams Fk Reservoir: even odds of at least 10 kAF over 06-01 to 07-31 — 18% 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 |
|---|---|---|---|---|---|
| Berthoud Summit | 11300 | 0.1 | 0.0 | — | May 3 (23.2 in) |
| Fool Creek | 11130 | 0.2 | — | — | — |
| High Lonesome | 10630 | 0.2 | — | — | — |
| Jones Pass | 10430 | 0.0 | 0.0 | — | April 27 (16.8 in) |
| Lake Irene | 10680 | 0.0 | 0.3 | — | April 26 (25.4 in) |
| Middle Fork Camp | 8960 | 0.2 | 0.0 | — | April 4 (11.5 in) |
| Phantom Valley | 9030 | 0.0 | 0.0 | — | March 30 (10.4 in) |
| Stillwater Creek | 8760 | 0.0 | — | — | — |
| Willow Creek Pass | 9520 | 0.6 | 0.0 | — | May 3 (16.4 in) |
Lake Granby Inflow — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 27 | 40 | 49 | 58 | 71 | 149 |
Willow Ck Reservoir Inflow — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 2 | 5 | 7 | 10 | 15 | 19 |
Williams Fk bl Williams Fk Reservoir — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 5 | 8 | 10 | 14 | 20 | 59 |
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: 7 parent disagreements, 20 sizable streams not on this network (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 27 streams, 20 agree. Know this water? Tell us →
| Stream | This site routes it to | DWR routes it to |
|---|---|---|
| Battle Creek | the mainstem | Williams Fork |
| Willow Creek | the mainstem | Little Muddy Creek |
| Smith Creek | the mainstem | Corral Creek |
| Pole Creek | Crooked Creek | Colorado River |
| Tenmile Creek | the mainstem | Fraser River |
| Crooked Creek | the mainstem | Fraser River |
| Hamilton Creek | the mainstem | Hurd Creek |
Sizable streams DWR maps here that this network does not carry:
Arapaho Creek (16 mi) · North Inlet (16 mi) · Little Muddy Creek (13 mi) · Beaver Creek (13 mi) · Onahu Creek (9 mi) · Kinney Creek (8 mi) · Drowsy Water Creek (8 mi) · Reeder Creek (8 mi)