Hydrohistorian
Blue River Basin on the ground — the ditches, wells, reservoirs and gages of Water District 36 · clicktap anything for its record
Snowpack — no snow on the ground at 6 SNOTEL sites — normal for the date; the snow year begins in October and typically peaks around April 26. Runoff outlook — Dillon Reservoir Inflow: even odds of at least 25 kAF over 06-01 to 07-31 — 25% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — Green Mountain Reservoir Inflow: even odds of at least 44 kAF over 06-01 to 07-31 — 27% 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 |
|---|---|---|---|---|---|
| Copper Mountain | 10500 | 0.0 | 0.0 | — | April 26 (17.4 in) |
| Elliot Ridge | 10550 | 0.0 | 0.0 | — | April 25 (23.2 in) |
| Fremont Pass | 11310 | 0.0 | 0.0 | — | May 11 (20.8 in) |
| Grizzly Peak | 11110 | 0.0 | 0.0 | — | April 21 (19.6 in) |
| Hoosier Pass | 11600 | 0.0 | 0.0 | — | April 27 (17.3 in) |
| Summit Ranch | 9350 | 0.0 | 0.0 | — | April 9 (11.4 in) |
Dillon Reservoir Inflow — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 12 | 18 | 25 | 34 | 46 | 101 |
Green Mountain Reservoir Inflow — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 25 | 35 | 44 | 55 | 70 | 163 |
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: 2 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, 25 agree. Know this water? Tell us →
| Stream | This site routes it to | DWR routes it to |
|---|---|---|
| West Tenmile Creek | the mainstem | Tenmile Creek |
| Soda Creek | the mainstem | Snake River |
Sizable streams DWR maps here that this network does not carry:
Cataract Creek (12 mi) · Slate Creek (10 mi) · Elliott Creek (9 mi) · Boulder Creek (9 mi) · French Gulch (8 mi) · Elliott Creek (7 mi) · Otter Creek (7 mi) · Beaver Creek (6 mi)
Full diagnostic snapshot pending — this district's weekly-style report (system status, active calls, hydrographs, anomaly flags) is produced by the nightly rotation and appears here after its first run. The tabs above are live now.
Schematic
Historical
Evolution of the network
Trends
This year, in context
In the weeks around 2026-07-06 (the newest reading on file), flows at the 13 ranked gages are running at a median 26% of their own long-term norm for this window — 12 below a typical year, 1 at or above. Driest relative to its record: BEMROSE-HOOSIER DIVERSION NEAR HOOSIER PASS, CO, ranking 7th lowest of 69 years.
How this comparison is made
Each gage's mean flow over the 3 days either side of 2026-07-06, 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 2026-08-30 20:10 from 46 gage(s) with cached period-of-record data. The series is each gage's annual mean flow in cfs (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 46 gages with enough record, 2 are trending down and 0 up, and 3 carry a detected shift. The clearest is Blue River at Dillon, its annual mean flow changing -7.76 cfs per decade (-7.1% of its median annual flow) over 50 years (p=0.0052). The other 43 show no clear signal either way.
| Gage | Trend | Change / decade cfs · % of median annual flow | Significance | Years | Changepoint |
|---|---|---|---|---|---|
|
▸
Blue River at Dillon BLUADICO |
↓ decreasing | -7.76 cfs -7.1% | p=0.005 | 50 | ~1930 |
|
▸
Blue River below Green Mountain Reservoir BLUGRECO |
↓ decreasing | -15.42 cfs -3.6% | p=0.017 | 88 | ~1962 |
|
▸
Tenmile Creek at Dillon TENDILCO |
no clear trend | -6.44 cfs -5.5% | p=0.095 | 39 | ~1930 |
43 other gage(s) show no significant trend or changepoint (not shown).
3 of those show a significant trend once extended backwards from a retired neighbour's record: Blue River near Dillon (115 yr, decreasing); Tenmile Creek Bl North Tenmile Creek, at Frisco (115 yr, decreasing); Blue River below Dillon (105 yr, decreasing). Those are reconstructions, not measurements — each gage's page shows both.
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. 15 gage(s) and 211 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1969. 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 | 1 | 0 |
| 1910s | 3 | 0 |
| 1920s | 1 | 0 |
| 1930s | 3 | 0 |
| 1940s | 15 | 0 |
| 1950s | 14 | 0 |
| 1960s | 14 | 66 |
| 1970s | 15 | 184 |
| 1980s | 16 | 227 |
| 1990s | 16 | 176 |
| 2000s | 15 | 184 |
| 2010s | 15 | 173 |
| 2020s | 15 | 204 |
Mass-balance (network closure) trend
Structure divrec-history backfill coverage as of the last check: 12% of 1747 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 (3195 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.
- BLUE RIVER BELOW GREEN MOUNTAIN RESERVOIR, CO: reach shifted from +268 cfs to +587 cfs summer mean (more gaining, p=0.043, 77 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
- TENMILE CREEK BELOW WEST TENMILE CREEK, CO: reach shifted from -55 cfs to -48 cfs summer mean (more gaining, p=0.043, 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]
- BLUE RIVER BELOW DILLON, CO.: reach shifted from +207 cfs to -52 cfs summer mean (more losing, p=0.001, 67 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [5 alluvial wells within 2 mi of the gage; pooled water table -2.0 ft (1973–2011, no_trend)]
- BOULDER CREEK AT UPPER STATION, NEAR DILLON, CO.: reach shifted from -15 cfs to -5 cfs summer mean (more gaining, p=0.049, 27 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
Groundwater now has its own tab: 29 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.
Reservoirs now has its own tab: 64 reservoir(s), end-of-year storage back to 1964, click-to-chart histories.
Cross-gage pattern fingerprint
Over the 69-year window with full coverage (1958–2026), 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 2026-07-06)
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.
- COUNTRY BOY MINE SPRING (return): +3.4 cfs (14% of that reach's correction)
- BRECKENRIDGE PIPELINE - AP (diversion): +3.4 cfs (14% of that reach's correction)
- BRECKENRIDGE SKI AREA PUMP PLANT & PIPEL (diversion): +3.4 cfs (14% of that reach's correction)
- CHRISTIE HEIGHTS D NO 1 (diversion): +3.4 cfs (14% of that reach's correction)
- ELYRIA DITCH (diversion): +3.4 cfs (14% of that reach's correction)
- ATKINS DITCH (diversion): +3.4 cfs (14% of that reach's correction)
- BRADDOCK DITCH (diversion): +3.4 cfs (14% of that reach's correction)
- TIGER RUN - BLUE RIVER DIVERSION (diversion): +2.8 cfs (25% of that reach's correction)
- GETZ POND (diversion): +2.8 cfs (25% of that reach's correction)
- VER PLOEG SPRING (return): +2.8 cfs (25% 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_20260707 (imported 2026-08-19) for history, plus the CDSS REST API for current conditions.
| Check | State | What was measured |
|---|---|---|
| gage freshness | stale | newest gage reading is 55 day(s) old (target 7) |
| diversion record | stale | newest diversion record is 669 day(s) old (DWR publishes ~1 year in arrears) |
| structure coverage | sparse | 12% of schematic structures have data |
Independent check: PASS — 100.0000% agreement across 37,314 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 — 99.89% day-level agreement with USGS's own published records for the same gages, across 40 co-listed station(s) and 414,582 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.
46 gage(s) / 440,490 daily values (1904-08-01–2026-07-06); 525 structure(s) with diversion records; 1247 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
104 water-level measurements across 29 monitored well(s) — 27 alluvial, 0 bedrock — plus 25 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.
TENMILE CREEK BELOW WEST TENMILE CREEK, CO: 0 alluvial well(s) nearby. Glover screen: 0.7 cfs of nearby metered alluvial pumping → est. lagged depletion 0.6–0.7 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).
BLUE RIVER BELOW DILLON, CO.: 5 alluvial well(s) nearby; pooled water table -2.0 ft (1973–2011, no_trend, p=0.9641)
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.
Reservoirs
64 reservoir(s) with 6,955 storage measurement(s), 1964–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 295,455 AF across 4 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) | |
|---|---|---|---|---|---|
| ▸ DILLON RESERVOIR (3604512) | 217,354 | 2024-10-31 | — | — | dossier → |
| ▸ GREEN MOUNTAIN RESERVOIR (3603543) | 76,976 | 2024-10-31 | — | — | dossier → |
| ▸ CLINTON GULCH RESERVOIR (3603575) | 4,205 | 2021-10-31 | — | — | dossier → |
| ▸ BLACK LAKE AND RESERVOIR (3603533) | 1,997 | 2010-10-31 | — | — | dossier → |
| ▸ CATARACT LAKE AND RESERVOIR (3603538) | 1,653 | 2010-10-31 | — | — | dossier → |
| ▸ GOOSE PASTURE TARN (3603542) | 805 | 2024-10-31 | — | — | dossier → |
| ▸ MIN LAKE MOHAWK NO 2 (3603586) | 444 | 1992-10-31 | — | — | dossier → |
| ▸ LOWER BLACK CREEK RESERVOIR (3603556) | 400 | 1988-09-22 | — | — | dossier → |
Snow and runoff
Snow-water equivalent, WY2026
No snow on the ground — normal for the date; the snow year begins in October. The chart shows the full water year just ending.
| SNOTEL site | Elev (ft) | SWE (in) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Copper Mountain | 10500 | 0.0 | 0.0 | — | April 26 (17.4 in) |
| Elliot Ridge | 10550 | 0.0 | 0.0 | — | April 25 (23.2 in) |
| Fremont Pass | 11310 | 0.0 | 0.0 | — | May 11 (20.8 in) |
| Grizzly Peak | 11110 | 0.0 | 0.0 | — | April 21 (19.6 in) |
| Hoosier Pass | 11600 | 0.0 | 0.0 | — | April 27 (17.3 in) |
| Summit Ranch | 9350 | 0.0 | 0.0 | — | April 9 (11.4 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 8 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. This year was one of the dry ones: the pack peaked at 52% of median.
The snow never came: 1981, 1987, 1991, 2002, 2004, 2012, 2021, 2026.
Computed by this site from 6 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 — Dillon Reservoir Inflow
NRCS's final issue (2026-06-01) calls it even odds that at least 25 kAF arrives over 06-01 to 07-31 — 25% of a normal season; almost certainly at least 12, probably not more than 46. Our own record at this gage shows 4 kAF actually delivered (partial record: 36 of 61 days). New forecasts begin in January. How to read these numbers →
| 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 |
|---|---|---|---|---|---|---|
| 12 | 18 | 25 | 34 | 46 | 101 | 4 |
How good are these forecasts here? (1973–2025)
Grading every April issue against what the river then delivered, measured at this gage’s own record — 52 seasons: the median miss of the 50% forecast is 86%, with a high bias of 86%, and the observed volume landed inside the stated 10–90% band 25% 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 (1979–2025)
Across 47 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 51% 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 2.6).
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 — Green Mountain Reservoir Inflow
NRCS's final issue (2026-06-01) calls it even odds that at least 44 kAF arrives over 06-01 to 07-31 — 27% of a normal season; almost certainly at least 25, probably not more than 70. Our own record at this gage shows 35 kAF actually delivered (partial record: 36 of 61 days). New forecasts begin in January. How to read these numbers →
| 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 |
|---|---|---|---|---|---|---|
| 25 | 35 | 44 | 55 | 70 | 163 | 35 |
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 73%, with a high bias of 73%, and the observed volume landed inside the stated 10–90% band 9% 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 (1979–2025)
Across 47 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 45% 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 2.4).
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.
Legal
Decreed rights on this network run from 1869-07-01 to 2022-08-29. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 10% of a median irrigation season and 0% in a dry one. 6 abandonment screens and 171 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: 2639 across 1247 structure(s); 392 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 call, calls set, seniority 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.
- BROWN ACORN DITCH (3600540) DWR↗ stopped 2024-07-22 (95+ days) — call at BULL CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DOMESTIC SUPPLY DITCH (3600591) DWR↗ stopped 2024-07-22 (95+ days) — call at BULL CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- C M OMER DITCH (3600569) DWR↗ stopped 2024-07-18 (99+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BRUSH CREEK DITCH (3600541) DWR↗ stopped 2024-07-17 (70+ days) — call at EAST DIVIDE CREEK DITCH curtailing 73% of its decreed rate [heuristic-partial]
- ALBER DITCH (3600507) DWR↗ stopped 2024-07-14 (66+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BELLS BLUE RIVER DITCH (3600520) DWR↗ stopped 2024-07-05 (15+ days) — call at ATKINSON DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BELL DITCH (3600517) DWR↗ stopped 2024-06-27 (23+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BELL NO 2 DITCH (3600519) DWR↗ stopped 2024-06-26 (10+ days) — call at EAST DIVIDE CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DRY CREEK DITCH - HEADGATE NO 1 (3600593) DWR↗ stopped 2024-06-14 (25+ days) — call at BAKER DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DRY CREEK NO 1 DITCH (3600594) DWR↗ stopped 2024-05-29 (114+ days) — call at HALKOWEIZ DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DRY CREEK NO 2 DITCH (3600595) DWR↗ stopped 2024-05-29 (114+ days) — call at HALKOWEIZ DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DRY CREEK NO 3 DITCH (3600596) DWR↗ stopped 2024-05-29 (114+ days) — call at HALKOWEIZ 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 |
|---|---|---|---|
| GREEN MTN HYDRO-ELECTRIC (3600881) DWR↗ | 1935-08-01 | 33.2% / 0.0% | 33.2% / 0.0% |
| BLUE RIVER DIVERSION PROJECT (3604684) DWR↗ | 1946-06-24 | 9.8% / 0.0% | 9.8% / 0.0% |
| TOWN OF BRECKENRIDGE WHITEWATER PARK (3607293) DWR↗ | 2000-12-21 | 5.6% / 0.0% | 5.6% / 0.0% |
| CLIMAX INTEGRATED WATER SYSTEM (3604923) DWR↗ | 1903-01-01 | 33.2% / 0.0% | 9.8% / 0.0% |
| CON-HOOSIER SYS BLUE RIVER DITCH (3604683) DWR↗ | 1948-05-13 | 9.8% / 0.0% | 5.6% / 0.0% |
| BLUE VALLEY RANCH HYDRO (3600985) DWR↗ | 1981-03-09 | 9.8% / 0.0% | 9.8% / 0.0% |
| MIN FLOW BLUE RIVER 9 - BOULDER CK TO SL (3602047) DWR↗ | 1904-05-23 | 100.0% / 0.0% | 9.8% / 0.0% |
| MIN FLOW BLUE RIVER 10 - SLATE CK TO GMR (3602048) DWR↗ | 1904-05-23 | 100.0% / 0.0% | 9.8% / 0.0% |
| MIN FLOW BLUE RIVER 8 - ROCK CK TO BOULD (3602046) DWR↗ | 1987-10-02 | 9.8% / 0.0% | 9.8% / 0.0% |
| CON-HOOSIER EAST HOOSIER DITCH (3604689) DWR↗ | 1929-08-05 | 33.2% / 0.0% | 9.8% / 0.0% |
| ELLIOTT CREEK FEEDER (3600606) DWR↗ | 1935-08-01 | 33.2% / 0.0% | 33.2% / 0.0% |
| MIN FLOW BLUE RIVER 11 - GMR TO COLORADO (3602049) DWR↗ | 1987-10-02 | 9.8% / 0.0% | 9.8% / 0.0% |
Abandonment radar (6 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 ~1969 — idleness that begins before then may be unreported use, not nonuse (flagged † below).
- SODA CREEK DITCH (3600809) DWR↗ (1900-07-01, 2.7 cfs decreed): last active 1969 — 11 years idle
- BENTON CREEK NO 1 DITCH (3600522) DWR↗ (1912-10-06, 4.2 cfs decreed): last active 1970 — 10 years idle
- BENTON CREEK NO 2 DITCH (3600523) DWR↗ (1904-10-30, 2.2 cfs decreed): last active 1970 — 10 years idle
- COULTER NO 1 DITCH (3600575) DWR↗ (1904-08-31, 0.8 cfs decreed): last active 1970 — 10 years idle
- COULTER NO 2 DITCH (3600576) DWR↗ (1913-04-24, 0.2 cfs decreed): last active 1970 — 10 years idle
- ENGLE DITCH (3600614) DWR↗ (1942-09-25, 4.1 cfs decreed): last active 1970 — 10 years idle
Compliance screens (171 advisory flags)
Screened 279 of 1247 structures with rights (341 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.
- MIN FLOW BLUE RIVER 5 - DILLON TO STRAIG (3602043) DWR↗: Observed p99 daily rate 947.0 cfs (max 1900.0) exceeds total decreed absolute 50.0 cfs across 5100 recorded day(s).
- MIN FLOW BLUE RIVER 4 - SWAN RIVER TO DI (3602037) DWR↗: Observed p99 daily rate 528.4 cfs (max 715.0) exceeds total decreed absolute 32.0 cfs across 4986 recorded day(s).
- BLUE VALLEY RANCH HYDRO (3600985) DWR↗: Observed p99 daily rate 222.0 cfs (max 222.0) exceeds total decreed absolute 129.0 cfs across 14666 recorded day(s).
- MIN FLOW BLUE RIVER 3 - SWAN RIVER UP TO (3602030) DWR↗: Observed p99 daily rate 177.0 cfs (max 339.0) exceeds total decreed absolute 20.0 cfs across 5822 recorded day(s).
- ELLIOTT CREEK FEEDER (3600606) DWR↗: Observed p99 daily rate 118.0 cfs (max 200.0) exceeds total decreed absolute 90.0 cfs across 17164 recorded day(s).
- MIN FLOW SNAKE RIVER LOW - NORTH FORK TO (3602033) DWR↗: Observed p99 daily rate 107.0 cfs (max 108.0) exceeds total decreed absolute 12.0 cfs across 4350 recorded day(s).
- MIN FLOW STRAIGHT CREEK (3602040) DWR↗: Observed p99 daily rate 90.6 cfs (max 125.0) exceeds total decreed absolute 2.5 cfs across 3580 recorded day(s).
- CON-HOOSIER SYS MCCULLOUGH DITCH (3604690) DWR↗: Observed p99 daily rate 76.0 cfs (max 128.4) exceeds total decreed absolute 60.0 cfs across 8214 recorded day(s).
- CON-HOOSIER TUNNEL (3604699) DWR↗: Observed p99 daily rate 65.7 cfs (max 163.5) exceeds total decreed absolute 20.0 cfs across 26128 recorded day(s).
- HOAGLAND CANAL (ELLIOT) (3600662) DWR↗: Observed p99 daily rate 65.0 cfs (max 69.9) exceeds total decreed absolute 25.0 cfs across 9969 recorded day(s).
Seniority (top structures by decreed rate)
| Structure | Senior priority date | Rights | Decreed abs (cfs) | Decreed abs (AF) | Conditional? |
|---|---|---|---|---|---|
| GREEN MTN HYDRO-ELECTRIC (3600881) DWR↗ | 1935-08-01 | 1 | 1726.0 | 0 | — |
| BLUE RIVER DIVERSION PROJECT (3604684) DWR↗ | 1946-06-24 | 1 | 654.0 | 0 | yes |
| TOWN OF BRECKENRIDGE WHITEWATER PARK (3607293) DWR↗ | 2000-12-21 | 1 | 500.0 | 0 | — |
| CLIMAX INTEGRATED WATER SYSTEM (3604923) DWR↗ | 1903-01-01 | 13 | 416.5 | 103 | yes |
| CON-HOOSIER SYS BLUE RIVER DITCH (3604683) DWR↗ | 1948-05-13 | 3 | 200.0 | 0 | — |
| BLUE VALLEY RANCH HYDRO (3600985) DWR↗ | 1981-03-09 | 1 | 129.0 | 0 | — |
| MIN FLOW BLUE RIVER 9 - BOULDER CK TO SL (3602047) DWR↗ | 1904-05-23 | 3 | 125.0 | 0 | — |
| MIN FLOW BLUE RIVER 10 - SLATE CK TO GMR (3602048) DWR↗ | 1904-05-23 | 2 | 125.0 | 0 | — |
| MIN FLOW BLUE RIVER 8 - ROCK CK TO BOULD (3602046) DWR↗ | 1987-10-02 | 1 | 115.0 | 0 | — |
| ELLIOTT CREEK FEEDER (3600606) DWR↗ | 1935-08-01 | 1 | 90.0 | 0 | — |
| CON-HOOSIER EAST HOOSIER DITCH (3604689) DWR↗ | 1929-08-05 | 2 | 90.0 | 0 | — |
| MIN FLOW BLUE RIVER 11 - GMR TO COLORADO (3602049) DWR↗ | 1987-10-02 | 1 | 85.0 | 0 | — |
| LOBACK DITCH (3600709) DWR↗ | 1930-12-31 | 4 | 75.8 | 0 | — |
| MIN FLOW BLUE RIVER 7 - ROCK CK TO WILLO (3602045) DWR↗ | 1987-10-02 | 1 | 75.0 | 0 | — |
| CON-HOOSIER SYS MCCULLOUGH DITCH (3604690) DWR↗ | 1948-05-13 | 3 | 60.0 | 0 | — |
No inventory or legal-document changes detected since the daily watch began.
Water-court filings this month (division-wide)
1 application in the 2026-08 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 2026-10-31 (61 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 1 filings, with excerpts
| Case | What it asks | County | Excerpt |
|---|---|---|---|
26CW3012
|
change of water right | RIO BLANCO | 26CW3012 Rio Blanco County. Application For Change of Water Right and Approval of Augmentation Plan. Applicant: Three Crown Ranch, LLC, Balcomb & Green, P.C., P.O. Drawer 790, Glenwood Springs, CO 81602, (970) 945-6546; balcombgreen.com. First Claim for Change… |
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 |
|---|---|---|---|---|---|
| CLIMAX MOLYBDENUM COMPANY EMERGENCY | 37-92-308(7) PLAN EMERGENCY | Approved | 2026-06-27 | — | plan file |
| SUMMIT COUNTY LANDFILL | 37-92-308(5) PLANS LESS THAN 5 YEARS | Approved | 2026-12-31 | — | plan file |
| COLORADO RIVER DISTRICT EMERGENCY 2026 | 37-92-308(7) PLAN EMERGENCY | Pending | — | 3807128 | plan file |
| GALLOWAY BLUE VALLEY RANCH | 37-92-308(5) PLANS LESS THAN 5 YEARS | Pending | — | — | plan file |
| MARYLAND CREEK (M1996049) | 37-90-137(11) GRAVEL PIT PLAN | Division Review | — | — | plan file |
| SILVERTHORNE, TOWN OF - UNION WELLS 25CW3161 | 37-92-308(4) PLAN PENDING COURT APPLICATION | Division Review | — | — | plan file |
| BRECKENRIDGE SKI AREA RESTAURANTS | 37-92-308(5) PLANS LESS THAN 5 YEARS | Additional Info Needed | — | — | plan file |
| CLIMAX MOLYBDENUM COMPANY (12CW0176) | 37-92-308(4) PLAN PENDING COURT APPLICATION | Unacceptable | — | — | plan file |
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.