Animas River Basin

Evolution of the network

This year, in context

In the weeks around 2026-07-06 (the newest reading on file), flows at the 20 ranked gages are running at a median 28% of their own long-term norm for this window — 19 below a typical year, 1 at or above. Driest relative to its record: CASCADE CANAL ABOVE CASCADE RESERVOIR, ranking 1st lowest of 35 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 21:15 from 34 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 34 gages with enough record, 7 are trending down and 1 up, and 5 carry a detected shift. The clearest is Cascade Canal above Cascade Reservoir, its annual mean flow changing -15.66 cfs per decade (-80.2% of its median annual flow) over 31 years (p<0.0001). The other 26 show no clear signal either way.

Drought history, cost, and the four-century context moved to the Drought tab.

Gage	Trend	Change / decade cfs · % of median annual flow	Significance	Years	Changepoint
▸ ⚠️ Cascade Canal above Cascade Reservoir☆ CASCANCO	↓ decreasing	-15.66 cfs -80.2%	p<0.001	31	~2012
▸ Florida Canal☆ FLOCANCO	↓ decreasing	-3.51 cfs -26.7%	p<0.001	27	~2008
▸ Florida River below Lemon Reservoir☆ FLOBLECO	↓ decreasing	-9.28 cfs -10.5%	p=0.003	53	~2001
▸ Florida River near Durango☆ FLODURCO	↓ decreasing	-18.90 cfs -18.9%	p=0.004	39	—
▸ Florida River at Bondad☆ FLOBONCO	↓ decreasing	-6.44 cfs -14.0%	p=0.017	41	—
▸ ⚠️ Elbert Creek below Cascade Reservoir☆ ELBCASCO	↑ increasing	+0.33 cfs +39.5%	p=0.017	25	~2011
▸ Florida River above Lemon Reservoir near Durango☆ FLOALECO	↓ decreasing extended 113 yr: no trend	-6.31 cfs -8.2%	p=0.018	53	~1999
▸ Animas River at Durango☆ ANIDURCO	↓ decreasing	-19.01 cfs -2.5%	p=0.020	111	—

⚠️ 2 gages flagged: their records may have quietly shifted against their neighbours, so treat their trends with caution.

How drift is detected

Every gage's annual flows are compared against each neighbour's as a double-mass curve (Searcy & Hardison, USGS WSP 1541-B); a Pettitt step test looks for a break in the ratio. A gage is flagged only when the breaks AGREE across its references, and a break against an already-suspect gage is never counted against a healthy one. A double-mass break means the ratio between two gages changed, not that either gage is faulty: a new diversion, a reservoir, or an import changes that ratio exactly as a rating shift does. Screening aid for expert review, never a measurement verdict.

26 other gage(s) show no significant trend or changepoint (not shown).

2 of those show a significant trend once extended backwards from a retired neighbour's record: Animas River below Durango Pump Plant near Durango (113 yr, decreasing); Cascade Cr above Cascade Cr Diversion near Rockwood (33 yr, decreasing, suspect). 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. 23 gage(s) and 319 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1968. 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)
1890s	1	0
1900s	1	0
1910s	1	0
1920s	3	0
1930s	4	138
1940s	8	110
1950s	6	122
1960s	8	114
1970s	9	231
1980s	5	241
1990s	11	277
2000s	18	286
2010s	22	331
2020s	24	314

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 12% of 2546 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 (1271 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.

• FLORIDA RIVER BELOW FLORIDA FARMERS CANAL NEAR DURANGO: reach shifted from -154 cfs to -8 cfs summer mean (more gaining, p=0.002, 39 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=0.5) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• FLORIDA RIVER AT BONDAD, CO.: reach shifted from +129 cfs to -58 cfs summer mean (more losing, p=0.000, 48 yr) [sedimentary plains/foothills: 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=-0.6) -- part of it may be unaccounted water becoming accounted, not hydrologic change]

Groundwater now has its own tab: 145 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 75 reservoir(s), end-of-year storage back to 1929, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 91-year window with full coverage (1936–2026), the dominant shared pattern across 3 gage(s) explains 94% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

All gages in this window move with the shared pattern -- no localized outlier.

Structures most implicated by reconciliation (as of 2026-07-06)

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.

• BLANCHE PLACER PIPE (diversion): +97.4 cfs (100% of that reach's correction)
• GNARLY SPRING (return): +5.6 cfs (5% of that reach's correction)
• STINKY SPRING (return): +5.6 cfs (5% of that reach's correction)
• WIMPY LADY SPRING (return): +5.6 cfs (5% of that reach's correction)
• UNICORN SPRING (return): +5.6 cfs (5% of that reach's correction)
• OLYMPIC SPRING (return): +5.6 cfs (5% of that reach's correction)
• ELK SPRING (return): +5.6 cfs (5% of that reach's correction)
• DEER PARK SPRING #2 (return): +5.6 cfs (5% of that reach's correction)
• MAZEPPA PIPELINE (diversion): +5.6 cfs (5% of that reach's correction)
• CATARACT GULCH SPRING (return): +5.6 cfs (5% of that reach's correction)

75 reservoir(s) with 25,201 storage measurement(s), 1929–2026. Basin storage as of 2025-10-31 (the record's own end — reservoir records publish ~annually): 145,284 AF across 31 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)
▸ RIDGES BASIN RESERVOIR (3003623) ☆	121,244	2025-10-31	—	—	dossier →
▸ CASCADE RESERVOIR (3003536) ☆	20,592	2024-10-31	—	—	dossier →
▸ LEMON RESERVOIR (3003581) ☆	14,164	2010-10-31	—	—	dossier →
▸ JOHNSON RESERVOIR (3003707) ☆	823	2025-10-29	—	—	dossier →
▸ KEELER RESERVOIR (3003547) ☆	488	2025-10-28	—	—	dossier →
▸ HAVILAND LAKE RESERVOIR (3003540) ☆	459	2025-10-31	—	—	dossier →
▸ DURANGO RESERVOIR NO 1 (3003571) ☆	450	1978-10-31	—	—	dossier →
▸ ICE LAKE RESERVOIR (3003546) ☆	416	2025-10-28	—	—	dossier →

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
Cascade #2	8990	0.0	0.0	—	March 6 (10.4 in)
Mineral Creek	10030	0.0	0.0	—	April 9 (15.6 in)
Molas Lake	10610	0.0	0.0	—	April 11 (22.0 in)
Red Mountain Pass	11060	0.0	0.0	—	April 25 (25.0 in)
Spud Mountain	10660	0.0	0.0	—	April 4 (25.6 in)
Stump Lakes	11230	0.0	0.0	—	April 22 (18.8 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 2 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 42% of median.

The snow never came: 1981, 1990, 2002, 2003, 2015, 2018, 2025, 2026. The snow left early: 2012, 2022.

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 — Animas R at Durango

NRCS's final issue (2026-06-01) calls it even odds that at least 52 kAF arrives over 06-01 to 07-31 — 29% of a normal season; almost certainly at least 20, probably not more than 93. Our own record at this gage shows 38 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
20	36	52	70	93	177	38

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 16%, with a high bias of 4%, and the observed volume landed inside the stated 10–90% band 84% 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 68% 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). In warm, early-melt years the river delivered a median of 58% of a normal season, against 107% in typical years — the timing of the melt matters, not just its size.

Computed by this site: the district’s April 1 SWE (% of each SNOTEL site’s own-record median) against the observed April–July volume at this gage (% of its median season) — a fixed window every year, unlike the forecast grades above, which use each issue’s own period. The slope is fit so single wild years can’t steer it (Theil–Sen, log space); years missing 10% of their days are dropped.

Runoff outlook — Lemon Reservoir Inflow

NRCS's final issue (2026-06-01) calls it even odds that at least 5 kAF arrives over 06-01 to 07-31 — 25% of a normal season; almost certainly at least 2, probably not more than 12. New forecasts begin in January. How to read these numbers →

The record-adjusted April benchmark

NRCS’s April issue (2026-04-01) called even odds at 13 kAF over 04-01 to 07-31. Re-anchoring that number on this river’s own history — how its April issues have verified, the winter’s baseflow, and the district’s April 1 snowpack — moves it to 13 kAF. The river delivered 16 kAF.

Computed by this site — not an NRCS number, and shown only because it earned it: replayed over 38 past seasons here (1988–2026), never seeing the year it predicts, the adjustment cut the typical April miss from 16% to 15%. At points where it does not beat NRCS, no adjusted number appears. Coefficients are frozen each August; the model never changes mid-season. Method and honest limits →

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
2	4	5	8	12	21

How good are these forecasts here? (1987–2026)

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) — 39 seasons: the median miss of the 50% forecast is 16%, with a high bias of 2%, and the observed volume landed inside the stated 10–90% band 88% 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 1.0). In warm, early-melt years the river delivered a median of 71% of a normal season, against 121% in typical years — the timing of the melt matters, not just its size. This year opened April at 24% of median snow and delivered 35% of a normal season.

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.

Right now

This is the 4th-driest week 27 in 115 years of record at ANIMAS RIVER AT DURANGO, CO (as of 2026-06-29; this week’s flow sits at the 3rd percentile for the date). On this week’s US Drought Monitor, La Plata County is 36% in D3 extreme drought (2026-09-01). The law agrees: the most senior active call leaves 98% of this district’s decreed flow rights junior to the calling right this week.

Every year since 1897, week by week

Each thin row is a year at ANIMAS RIVER AT DURANGO, 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.

The Drought Monitor’s view since 2000

Mean share of area in each class across Clear Creek, La Plata, San Juan counties — the counties this district’s gages sit in, which overlap the district imperfectly. The Drought Monitor weighs soils, vegetation and local reports; it is CONTEXT beside the river’s own record above, not the water-rights picture.

The law’s own drought gauge

When water runs short, administration answers: calls reach further back in time, and more decreed rights go junior to the calling right. This is that response, weekly since 2002 — 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 (205 calls touching this district) against the district’s rights index. Scoping is deliberately coarse — a call’s own district, or districts named in its comments — and this is administration’s RESPONSE, not a per-structure verdict (each dossier’s curtailment card does that, with stream miles). A deepening call can also reflect growing demand, not only shrinking supply.

This basin’s droughts, by its own record

Drought	Span	Weeks	Trough percentile	Recovery
unnamed dry spell	2025-05-05 → 2025-12-29	34	18th (2025-09-01)	8 weeks
unnamed dry spell	2023-11-27 → 2024-10-28	48	5th (2024-04-08)	69 weeks
the 2020-22 drought	2020-01-27 → 2022-10-24	143	1st (2021-03-22)	40 weeks
the 2018 drought	2017-12-25 → 2019-06-10	76	4th (2018-07-02)	2 weeks
the 2012-13 drought	2012-09-10 → 2013-11-18	62	5th (2012-11-26)	1 week
unnamed dry spell	2009-10-26 → 2010-07-19	38	11th (2010-01-25)	52 weeks
the 2002 drought	2001-11-26 → 2003-11-17	103	3rd (2002-09-02)	33 weeks
unnamed dry spell	1989-10-23 → 1990-11-05	54	5th (1990-04-30)	0 weeks
the 1981 drought	1981-03-16 → 1981-11-09	34	20th (1981-07-06)	0 weeks
the 1977 drought	1978-11-27 → 1979-04-16	20	25th (1978-12-25)	1 week
the 1977 drought	1977-02-14 → 1978-06-12	69	5th (1977-07-11)	5 weeks
unnamed dry spell	1974-06-24 → 1975-07-07	54	17th (1974-10-07)	1 week
unnamed dry spell	1967-11-13 → 1968-05-27	28	26th (1968-02-12)	6 weeks
unnamed dry spell	1966-10-31 → 1967-04-17	24	25th (1966-11-28)	64 weeks

Detected mechanically: the 26-week smoothed percentile below the 30th for at least 20 weeks; recovered on regaining the 50th. 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.

What drought has cost here

Since 1994, federal crop insurance has paid $689,401 in drought-caused claims across Clear Creek, La Plata, San Juan counties — 18.3% of all insured crop losses there. The worst year was 2002 ($75,597).

USDA crop-insurance indemnities where the recorded cause of loss is drought, summed over the counties this district's gages sit in. Counties overlap water districts imperfectly, and insured-crop claims are a floor on drought damage, not a total. Source: USDA RMA cause-of-loss files.

When this basin claimed its water

Every bar is a year’s new appropriations (2,255 rights across 119 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is +0.02 — essentially no wet-dry pattern; here, law and settlement set the pace, not the weather. Across the state both behaviors exist: ephemeral southwest basins file after wet demonstrations, transbasin-source basins under drought — and the biggest statewide filing waves sat in the 1950s drought and after 2002, not in the wet 1980s–90s.

Appropriation dates are the CLAIMED initiation of a right, not the courthouse filing date; the record is survivor-biased (abandoned claims are absent, so failed dry-era scrambles are undercounted); and the big 1960s and 2000s spikes sit on legal events — the pre-1969-Act adjudication era and 2000s legislation — not on weather. A correlation here is a description, never a cause.

New to how a dry winter becomes a call on the river? Anatomy of a drought walks the chain in four minutes — snow to rivers to reservoirs to calls to the water table.

Decreed rights on this network run from 1868-03-02 to 2025-07-31. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 3% of a median irrigation season and 0% in a dry one. 4 abandonment screens and 271 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: 2854 across 2277 structure(s); 465 structure(s) carry 6 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.

Is the river getting harder to divert from?

Over 2003–2025, administration on this district has been tightening: 1 of 3 measures (days under 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 (23 years); partly-covered years are omitted rather than reported as quiet. Trend is Mann-Kendall with the same significance gate as every other trend on this site. Counted from DWR's published call record, which begins in the early 2000s: earlier years are absent, not quiet. A rise in the number of calls set can also reflect how finely an administrator records one episode, which is why days under call -- insensitive to that -- is the component to read first. Advisory summary of the public record, not an administrative finding.

Year	Days under call	Calls set	Controlling priority (median)
2014	319	117	1883-05-15
2015	316	90	1899-05-13
2016	273	94	1888-02-08
2017	297	98	1904-01-02
2018	285	164	1878-05-15
2019	186	53	1880-06-01
2020	240	171	1986-11-23
2021	246	143	1876-11-01
2022	261	161	1888-03-20
2023	198	82	1880-06-01
2024	231	114	1876-10-10
2025	281	169	1888-03-20

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

• BUTLER DITCH (3000518) DWR↗☆ stopped 2025-10-06 (22+ days) — call at MOLLY'S DITCH curtailing 71% of its decreed rate [heuristic-partial]
• GAINES-BUCHANAN DITCH (3000551) DWR↗☆ stopped 2025-09-14 (7+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• BEAR CREEK DITCH (3000510) DWR↗☆ stopped 2025-08-17 (7+ days) — call at SPRING CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
• BUTLER DITCH (3000518) DWR↗☆ stopped 2025-08-11 (14+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• FISH DITCH (3000548) DWR↗☆ stopped 2025-06-30 (22+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• EMBLING-MAYER DITCH (3000539) DWR↗☆ stopped 2025-05-19 (7+ days) — call at HENRY BOLEN DITCH curtailing 81% of its decreed rate [heuristic-partial]
• BUTLER DITCH (3000518) DWR↗☆ stopped 2024-10-03 (235+ days) — call at SPRING CREEK DITCH curtailing 71% of its decreed rate [heuristic-partial]
• DUDLEY AND KERR DITCH (3000532) DWR↗☆ stopped 2024-09-17 (7+ days) — call at HENRY BOLEN DITCH curtailing 50% of its decreed rate [heuristic-partial]
• GAINES-BUCHANAN DITCH (3000551) DWR↗☆ stopped 2024-09-17 (21+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• F STEINEGGER IRG DITCH (3000543) DWR↗☆ stopped 2024-08-05 (450+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• AMBOLD-WALLACE DITCH (3000504) DWR↗☆ stopped 2024-05-19 (9+ days) — call at COTTONWOOD DITCH NO 2 curtailing 100% of its decreed rate [heuristic-strong]
• BUTLER DITCH (3000518) DWR↗☆ stopped 2023-10-04 (246+ days) — call at SPRING CREEK DITCH curtailing 71% of its decreed rate [heuristic-partial]

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
DURANGO BOATING PARK STRUCTURE 5 (3001691) DWR↗☆	2006-02-23	1.8% / 0.0%	1.8% / 0.0%
DURANGO BOATING PARK STRUCTURE 12 (3001694) DWR↗☆	2006-02-23	1.8% / 0.0%	1.8% / 0.0%
DURANGO BOATING PARK STRUCTURE 11 (3001693) DWR↗☆	2006-02-23	1.8% / 0.0%	1.8% / 0.0%
DURANGO BOATING PARK STRUCTURE 9 (3001692) DWR↗☆	2006-02-23	1.8% / 0.0%	1.8% / 0.0%
CASCADE CANAL (3000523) DWR↗☆	1902-10-02	4.4% / 0.0%	2.3% / 0.0%
ANIMAS DIVERSION CANAL (3000509) DWR↗☆	1938-09-02	2.3% / 0.0%	2.3% / 0.0%
POWER CANAL NO 1 (3000612) DWR↗☆	1902-10-02	4.4% / 0.0%	4.4% / 0.0%
FLORIDA FARMERS DITCH (3001011) DWR↗☆	1883-12-05	46.5% / 18.2%	1.8% / 0.0%
LITTLE CASCADE CR CANAL (3000588) DWR↗☆	1902-10-02	4.4% / 0.0%	4.4% / 0.0%
FLORIDA CANAL (3001013) DWR↗☆	1888-09-29	30.1% / 11.7%	1.8% / 0.0%
ANIMAS CONSOLIDATED D (3000506) DWR↗☆	1875-01-01	100.0% / 100.0%	2.3% / 0.0%
REID DITCH (3000617) DWR↗☆	1876-01-01	100.0% / 48.1%	1.8% / 0.0%

Abandonment radar (4 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 ~1968 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• FLORIDA CANAL AND RES (3003576) DWR↗☆ (1911-05-29, 0.0 cfs decreed): last active 1955 — 19 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1968) -- early absence of record is weak evidence of nonuse
• WATER WITCH DITCH (3000672) DWR↗☆ (1882-05-05, 0.2 cfs decreed): last active 1958 — 16 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1968) -- early absence of record is weak evidence of nonuse
• MCCLUER MURRAY ANNALA EX (3001531) DWR↗☆ (1878-04-15, 0.5 cfs decreed): last active 1960 — 14 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1968) -- early absence of record is weak evidence of nonuse
• JAMES DITCH (3000578) DWR↗☆ (1908-04-04, 0.5 cfs decreed): last active 1962 — 12 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1968) -- early absence of record is weak evidence of nonuse

Compliance screens (271 advisory flags)

Screened 439 of 2277 structures with rights (507 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.

• ANIMAS CONSOLIDATED D (3000506) DWR↗☆: Observed p99 daily rate 88.7 cfs (max 104.0) exceeds total decreed absolute 85.9 cfs across 73040 recorded day(s).
• REID DITCH (3000617) DWR↗☆: Observed p99 daily rate 77.9 cfs (max 116.5) exceeds total decreed absolute 64.4 cfs across 75517 recorded day(s).
• ANIMAS DITCH (3001023) DWR↗☆: Observed p99 daily rate 61.0 cfs (max 74.0) exceeds total decreed absolute 56.2 cfs across 48557 recorded day(s).
• J P LAMB DITCH (3000581) DWR↗☆: Observed p99 daily rate 35.0 cfs (max 40.0) exceeds total decreed absolute 7.0 cfs across 30629 recorded day(s).
• EAST FORK HERMOSA CREEK (3001929) DWR↗☆: Observed p99 daily rate 24.6 cfs (max 79.6) exceeds total decreed absolute 3.0 cfs across 3133 recorded day(s).
• GREGG PIPELINE (3001115) DWR↗☆: Observed p99 daily rate 24.0 cfs (max 24.0) exceeds total decreed absolute 0.8 cfs across 484 recorded day(s).
• TWIN ROCK DITCH (3004665) DWR↗☆: Observed p99 daily rate 21.5 cfs (max 27.2) exceeds total decreed absolute 2.2 cfs across 40259 recorded day(s).
• HERMOSA COMPANY DITCH (3000568) DWR↗☆: Observed p99 daily rate 19.0 cfs (max 27.6) exceeds total decreed absolute 12.5 cfs across 42894 recorded day(s).
• NORTON PUMP AND PL (3000606) DWR↗☆: Observed p99 daily rate 18.0 cfs (max 18.0) exceeds total decreed absolute 0.2 cfs across 668 recorded day(s).
• PIONEER DITCH (3001019) DWR↗☆: Observed p99 daily rate 17.0 cfs (max 38.0) exceeds total decreed absolute 14.9 cfs across 47277 recorded day(s).

Seniority (top structures by decreed rate)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Decreed abs (AF)	Conditional?
DURANGO BOATING PARK STRUCTURE 5 (3001691) DWR↗☆	2006-02-23	1	1400.0	0	—
DURANGO BOATING PARK STRUCTURE 9 (3001692) DWR↗☆	2006-02-23	1	1400.0	0	—
DURANGO BOATING PARK STRUCTURE 11 (3001693) DWR↗☆	2006-02-23	1	1400.0	0	—
DURANGO BOATING PARK STRUCTURE 12 (3001694) DWR↗☆	2006-02-23	1	1400.0	0	—
CASCADE CANAL (3000523) DWR↗☆	1902-10-02	2	400.0	0	—
ANIMAS DIVERSION CANAL (3000509) DWR↗☆	1938-09-02	2	287.0	0	yes
POWER CANAL NO 1 (3000612) DWR↗☆	1902-10-02	1	250.0	0	—
FLORIDA FARMERS DITCH (3001011) DWR↗☆	1883-12-05	8	185.0	0	—
LITTLE CASCADE CR CANAL (3000588) DWR↗☆	1902-10-02	1	120.0	0	—
FLORIDA CANAL (3001013) DWR↗☆	1888-09-29	4	111.0	0	—
ANIMAS CONSOLIDATED D (3000506) DWR↗☆	1875-01-01	8	85.9	0	—
REID DITCH (3000617) DWR↗☆	1876-01-01	12	64.4	0	—
ANIMAS DITCH (3001023) DWR↗☆	1868-03-02	5	56.2	0	—
HERMOSA CR(LOWER REACH) (3001928) DWR↗☆	1984-07-13	1	37.0	0	—
EAST MESA DITCH (3001094) DWR↗☆	1904-07-19	2	26.0	0	—

No inventory or legal-document changes detected since the daily watch began.

Water-court filings this month (division-wide)

4 applications in the 2026-07 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 2026-09-30 (25 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 4 filings, with excerpts

Case	What it asks	County	Excerpt
2026CW3007 3001335	change of water right	LA PLATA	2026CW3007 La Plata County, AMENDED APPLICATION FOR CHANGE OF WATER RIGHT AND NEW WATER RIGHTS. 1. Name and address of Applicants : Gilleland Enterprises, LLC and C&J Gravel Products, Inc. (“Applicants”)c/o John Gilleland 27661 Highway 160 Durango, CO 81301 jo…
2026CW3016	reasonable diligence	LA PLATA	2026CW3016 La Plata County, Application for Finding of Reasonable Diligence in the Florida River Watershed; Prior case no. 18CW3047: Applicant: The Bingel-Davis Gratitude Trust, u/a dated April 17, 2025, c/o Kimberly C. Perdue, Southwest Water and Property Law…
2026CW3017	—	LA PLATA	2026CW3017 La Plata County, (20CW3008, 13CW3027, 05CW90)…
2026CW4	—	ARCHULETA	2026CW4 Archuleta County, Jess E. Ketchum, 320 Stevens Lake Road, Pagosa Springs, CO 81147: Watson Reservoir (Reservoir Pump); Located in the SW 1/4 SE 1/4 of Section 5, T35N, R2W, NMPM, the axis intersects the East abutment at a point approximately 875 ft. No…

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
SWWCD EMERGENCY	37-92-308(7) PLAN EMERGENCY	Approved	2026-10-06	3007106	plan file
NORTHERN SAN JUAN BASIN FRUITLAND FORMATION FLORIDA AND PINE RIVER	37-92-308(4) PLAN PENDING COURT APPLICATION	Decreed	—	—	plan file

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.

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

Administration number
Simulate

DWR administration numbers encode appropriation and adjudication dates; lower is more senior.