Arkansas: Headwaters to Salida

Source Our computation, no independent reference · computed here from the screened DWR record Source Our computation, no independent reference · no independent reference; see /methods

This year, in context

In the weeks around 2026-09-27 (the newest reading on file), flows at the 33 ranked gages are running at a median 86% of their own long-term norm for this window — 20 below a typical year, 13 at or above. Driest relative to its record: CHARLES H. BOUSTEAD TUNNEL, ranking 1st lowest of 55 years.

Gage flow trend & changepoints

Of the 62 gages with enough record, 1 is trending down and 1 up, and 3 carry a detected shift. The clearest is Homestake-Otero Pumps near Granite, its annual mean flow changing +42.00 cfs per decade (+94.8% of its median annual flow) over 8 years (p=0.0094). The other 55 show no clear signal either way. 3 transbasin gages meter imported or exported water — marked ⇆ below and kept out of these counts, because that flow is an operator's decision, not the basin's hydrology (all transbasin diversions).

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

⚠️ 3 gages flagged: their records may have quietly shifted against their neighbours, so treat their trends with caution.

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

1 of those show a significant trend once extended backwards from a retired neighbour's record: East Fork Arkansas River at US Highway 24, near Leadville (79 yr, increasing, 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. 42 gage(s) and 153 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1973. 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 †.

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 3% of 4628 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 (4327 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.

• ARKANSAS RIVER AT BUENA VISTA, CO.: reach shifted from +959 cfs to +792 cfs summer mean (more losing, p=0.027, 23 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] [11 alluvial wells within 2 mi of the gage; pooled water table +1.3 ft (1971–2003, no_trend)]
• ARKANSAS RIVER AT GRANITE, CO.: reach shifted from +700 cfs to +266 cfs summer mean (more losing, p=0.000, 77 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] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=-0.47) -- part of it may be unaccounted water becoming accounted, not hydrologic change] [2 alluvial wells within 2 mi of the gage; pooled water table -0.4 ft (1972–1994, no_trend)]
• SOUTH ARKANSAS RIVER NEAR SALIDA, CO.: reach shifted from -47 cfs to -15 cfs summer mean (more gaining, p=0.010, 18 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=0.62) -- part of it may be unaccounted water becoming accounted, not hydrologic change] [9 alluvial wells within 2 mi of the gage; pooled water table +1.3 ft (1990–2009, no_trend)]
• ARKANSAS RIVER AT SALIDA, CO.: reach shifted from +1277 cfs to -54 cfs summer mean (more losing, p=0.002, 77 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=-0.63) -- part of it may be unaccounted water becoming accounted, not hydrologic change] [19 alluvial wells within 2 mi of the gage; pooled water table +4.2 ft (1971–2025, decreasing)]
• CLEAR CREEK ABOVE CLEAR CREEK RESERVOIR, CO.: reach shifted from -686 cfs to -426 cfs summer mean (more gaining, p=0.001, 75 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] [2 alluvial wells within 2 mi of the gage; pooled water table -0.4 ft (1972–1994, no_trend)]
• LAKE FORK CREEK BELOW SUGAR LOAF DAM NEAR LEADVILLE: reach shifted from +34 cfs to -116 cfs summer mean (more losing, p=0.000, 52 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=-0.63) -- part of it may be unaccounted water becoming accounted, not hydrologic change]

Groundwater now has its own tab: 221 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 9 reservoir(s), end-of-year storage back to 1949, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 92-year window with full coverage (1935–2026), the dominant shared pattern across 3 gage(s) explains 61% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

TWITUNCO doesn't move with that shared pattern -- a real, localized signal (a new diversion, land-use change, or a gage-specific data problem) worth a closer look, not necessarily noise.

Structures most implicated by reconciliation (as of 2026-09-27)

Which structures' data absorbed the most correction when the current mass-balance snapshot was reconciled -- see the Historical tab for the full picture on any date.

• 1113962 (diversion): +3.4 cfs (6% of that reach's correction)
• 1113469 (diversion): +3.4 cfs (6% of that reach's correction)
• SALIDA RIVERSIDE PARK IRRG SYSTEM (diversion): +3.4 cfs (6% of that reach's correction)
• SALIDA MARVIN PARK IRRG SYSTEM (diversion): +3.4 cfs (6% of that reach's correction)
• WILLARD SPRING PIPELINE (return): +3.4 cfs (6% of that reach's correction)
• D&RGW SALIDA STATION (diversion): +3.4 cfs (6% of that reach's correction)
• 1113343 (diversion): +3.4 cfs (6% of that reach's correction)
• 1113345 (diversion): +3.4 cfs (6% of that reach's correction)
• 1114036 (diversion): +3.4 cfs (6% of that reach's correction)
• 1113474 (diversion): +3.4 cfs (6% of that reach's correction)

Source DWR administrative record · verify at DWR groundwater wells ↗ Source DWR administrative record · verify at DWR well permits ↗

3,234 water-level measurements across 221 monitored well(s) — 142 alluvial, 0 bedrock — plus 3 administered well(s) reporting metered pumping.

Well map

3D aquifer x-ray

Every aquifer unit as its own head surface, animated through time.

Water-table trends

Of 23 well(s) with enough record for a trend test: 9 declining, 1 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.

ARKANSAS RIVER AT BUENA VISTA, CO.: 11 alluvial well(s) nearby; pooled water table +1.3 ft (1971–2003, no_trend, p=0.4573)

ARKANSAS RIVER AT GRANITE, CO.: 2 alluvial well(s) nearby; pooled water table -0.4 ft (1972–1994, no_trend, p=0.8267)

SOUTH ARKANSAS RIVER NEAR SALIDA, CO.: 9 alluvial well(s) nearby; pooled water table +1.3 ft (1990–2009, no_trend, p=0.8711). Glover screen: 0.3 cfs of nearby metered alluvial pumping → est. lagged depletion 0.2–0.3 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

ARKANSAS RIVER AT SALIDA, CO.: 19 alluvial well(s) nearby; pooled water table +4.2 ft (1971–2025, decreasing, p=0.0001). Glover screen: 0.3 cfs of nearby metered alluvial pumping → est. lagged depletion 0.3–0.3 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

CLEAR CREEK ABOVE CLEAR CREEK RESERVOIR, CO.: 2 alluvial well(s) nearby; pooled water table -0.4 ft (1972–1994, no_trend, p=0.8267)

LAKE FORK CREEK BELOW SUGAR LOAF DAM NEAR LEADVILLE: 1 alluvial well(s) nearby

LAKE CREEK BELOW TWIN LAKES RESERVOIR: 1 alluvial well(s) nearby

CHALK CREEK AT NATHROP: 5 alluvial well(s) nearby; pooled water table -1.3 ft (1972–2025, decreasing, p=0.0269)

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.

Source DWR administrative record · verify at DWR structure records ↗

9 reservoir(s) with 17,935 storage measurement(s), 1949–2018. Basin storage as of 2018-04-30 (the record's own end — reservoir records publish ~annually): 103,958 AF across 2 reservoir(s).

Reservoir map — how full is each vessel?

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.

Source Independent agency measurement · fetched 2026-10-14 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record

Snow-water equivalent, WY2027

A trace of snow at 2 of 2 sites (0.3 in of water at most); the median for the date is zero, so there is no percent to show yet. The snow year begins in October. The new water year began October 1; the chart fills in a day at a time as NRCS publishes each reading.

NRCS SNOTEL, daily. Sites are assigned to the district whose boundary contains them — the snow that feeds this district can also sit in a neighboring headwater district.

Two ways a snow year goes wrong (1981–2026)

A bad snow year here comes in two flavors (both called snow droughtA winter that shorts the snowpack. It happens two ways: a dry one, where the snow never comes, and a warm one, where near-normal snow falls but melts off weeks early -- and the river feels them differently.), and the river feels them differently. In 6 of the last 46 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, 1992, 2002, 2004, 2012, 2026.

Computed by this site from 2 SNOTEL sites’ full daily records (NRCS AWDB, back to 1981). Each year is measured against each site’s own multi-decade median — not the 1991–2020 normal the chart above uses — so the 1980s grade against a fair baseline. Peak and melt-out need 85% of the season’s days on the record; thin years are dropped, not guessed. Derived from snow measurements alone — it cannot tell dry-from-warm causes apart, only what the snowpack did.

Runoff outlook — Chalk Ck nr Nathrop

NRCS's final issue (2026-06-01) calls it even odds that at least 7 kAF arrives over 06-01 to 09-30 — 43% of a normal season; almost certainly at least 2, probably not more than 13. 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 70 replayed seasons (25% typical miss unadjusted vs 28% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

Runoff outlook — Arkansas R at Salida

NRCS's final issue (2026-06-01) calls it even odds that at least 68 kAF arrives over 06-01 to 09-30 — 35% of a normal season; almost certainly at least 30, probably not more than 106. Our own record at this gage shows 56 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 88 replayed seasons (17% typical miss unadjusted vs 20% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

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 — 74 seasons: the median miss of the 50% forecast is 17%, with a low bias of 10%, and the observed volume landed inside the stated 10–90% band 65% of the time (a calibrated forecast would say 80%).

Computed by this site: NRCS's archived April issues (their period as issued each year) against the observed volume in DWR’s published record; years with under 90% daily coverage are dropped, not summed. A grade of the forecast, never of the forecasters — these are hard rivers. How this point ranks among every graded Colorado forecast point →

What April snow has meant for this river (1981–2026)

Across 46 measured years, the season’s water has closely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 72% 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).

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.

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 3rd-driest week 39 in 117 years of record at ARKANSAS RIVER AT SALIDA, CO. (as of 2026-09-21; this week’s flow sits at the 3rd 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, Lake County is 100% in D4 exceptional drought (2026-10-06). The law agrees: the most senior active call leaves 92% of this district’s decreed flow rights junior to the calling right this week.

Every year since 1909, week by week

Each thin row is a year at ARKANSAS RIVER AT SALIDA, 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 39 weeks recorded so far, 2026’s weekly trace most resembles 2002 (mean gap 11.6 percentile points; next closest 1931 (16.3), 2004 (17.0)). 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 Chaffee, Eagle, Lake, Saguache 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 2005 — 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 (563 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

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.

What drought has cost here

Since 2018, federal crop insurance has paid $16,321 in drought-caused claims across Chaffee, Eagle, Lake, Saguache counties — 0.0% of all insured crop losses there. The worst year was 2018 ($16,321).

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 (1,325 rights across 118 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is -0.04 — 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.

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 ↗

15 systems touch this district (15 community systems reporting 21,513 people served, a figure that counts a wholesaler's customers twice); none carries an open health-based violation on EPA's record.

and 7 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 ↗

92 reaches over 409.0 miles and 46 natural lake levels, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →

• Browns Creek, 13.0 mi: 2 (10/1 - 4/30), 5 (5/1 - 9/30) cfs (appropriated 1975, 75W4287) · dossier
• Chalk Creek, 10.0 mi: 18 (1/1 - 12/31) cfs (appropriated 1977, 77W4662) · dossier
• East Fork Arkansas River, 10.0 mi: 15 (1/1 - 12/31) cfs (appropriated 1977, 77W4646) · dossier
• Silver Creek, 10.0 mi: 4 (1/1 - 12/31) cfs (appropriated 1977, 77W4656) · dossier
• South Cottonwood Creek, 10.0 mi: 10 (1/1 - 12/31) cfs (appropriated 1977, 77W4665) · dossier
• Middle Cottonwood Creek, 9.0 mi: 10 (1/1 - 12/31) cfs (appropriated 1977, 77W4667) · dossier

and 132 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 1860-05-01 to 2023-08-30. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 0% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 179 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: 1939 across 1491 structure(s); 310 structure(s) carry 0 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.

Is the river getting harder to divert from?

Over 2003–2025, administration on this district has been tightening: 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.

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

• YOUNG & SMITH DITCH (1100516) DWR↗☆ stopped 2025-09-30 (8+ days) — call at MARTIN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• WELLS & STARR DITCH (1100526) DWR↗☆ stopped 2025-09-21 (17+ days) — call at HOEHNE DITCH curtailing 100% of its decreed rate [heuristic-strong]
• YOUNGER DITCH NO 2 (1100521) DWR↗☆ stopped 2025-08-03 (89+ days) — call at TITSWORTH DITCH curtailing 100% of its decreed rate [heuristic-strong]
• SUNNYSIDE PARK DITCH (1100539) DWR↗☆ stopped 2025-04-03 (59+ days) — call at HOWARD DITCH(W FOURMILE) curtailing 100% of its decreed rate [heuristic-strong]
• HARRINGTON DITCH (1100550) DWR↗☆ stopped 2025-02-06 (35+ days) — call at CHILILI DITCH curtailing 100% of its decreed rate [heuristic-strong]
• YOUNGER DITCH NO 2 (1100521) DWR↗☆ stopped 2024-11-01 (197+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• KRAFT DITCH (1100530) DWR↗☆ stopped 2024-11-01 (186+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• SUNNYSIDE PARK DITCH (1100539) DWR↗☆ stopped 2024-11-01 (114+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• DEL MONTE IRRIG DITCH (1100548) DWR↗☆ stopped 2024-11-01 (132+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• BURNETT DITCH (1100552) DWR↗☆ stopped 2024-11-01 (157+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• PINON DITCH (1100553) DWR↗☆ stopped 2024-11-01 (173+ days) — call at MODEL DITCH curtailing 100% of its decreed rate [heuristic-strong]
• NOLAND DITCH (1100555) DWR↗☆ stopped 2024-11-01 (163+ days) — call at MODEL 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.

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 ~1973 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• BLOW DITCH - EMPIRE CREEK (1100729) DWR↗☆ (1890-12-01, 2.0 cfs decreed): last active 1912 — 113 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• IRON SILVER MINING CO-EVANS GULCH BRANCH (1100757) DWR↗☆ (1904-06-02, 0.3 cfs decreed): last active 1912 — 113 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• RESURRECTION DITCH (1100758) DWR↗☆ (1904-06-01, 3.3 cfs decreed): last active 1912 — 113 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• EGGLESTON DITCH (1100846) DWR↗☆ (1885-04-20, 1.0 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• PINON CANON DITCH (1100847) DWR↗☆ (1886-09-01, 3.4 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• ROCK CLIFF DITCH (1100852) DWR↗☆ (1890-01-30, 2.0 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• LIPPARD DITCH (1100853) DWR↗☆ (1895-05-01, 2.0 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• TOWN DITCH (1100854) DWR↗☆ (1895-05-01, 1.5 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• SCANGA DITCH (1100856) DWR↗☆ (1896-07-01, 2.8 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse
• WILLIAMS DITCH (1100876) DWR↗☆ (1877-04-30, 1.0 cfs decreed): last active 1913 — 112 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1973) -- early absence of record is weak evidence of nonuse

Compliance screens (179 advisory flags)

Screened 261 of 1491 structures with rights (283 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.

• TURQUOISE RESERVOIR (1103500) DWR↗☆: Observed p99 daily rate 773.1 cfs (max 1260.9) exceeds total decreed absolute 3.0 cfs across 14068 recorded day(s).
• OTERO PUMP STATION (1100529) DWR↗☆: Observed p99 daily rate 180.5 cfs (max 180.7) exceeds total decreed absolute 1.7 cfs across 4079 recorded day(s).
• SALIDA "OLD" GALLERY (1100882) DWR↗☆: Observed p99 daily rate 76.5 cfs (max 110.2) exceeds total decreed absolute 2.5 cfs across 3126 recorded day(s).
• CHAMP DITCH (ARK) (1100517) DWR↗☆: Observed p99 daily rate 52.8 cfs (max 52.8) exceeds total decreed absolute 5.0 cfs across 10846 recorded day(s).
• BOWEN DITCH (1100691) DWR↗☆: Observed p99 daily rate 50.0 cfs (max 55.5) exceeds total decreed absolute 44.5 cfs across 7674 recorded day(s).
• BUSK-IVANHOE SYSTEM (1104612) DWR↗☆: Observed p99 daily rate 48.6 cfs (max 74.7) exceeds total decreed absolute 17.5 cfs across 15739 recorded day(s).
• HELENA DITCH (1100535) DWR↗☆: Observed p99 daily rate 40.0 cfs (max 50.5) exceeds total decreed absolute 36.0 cfs across 17198 recorded day(s).
• MCFARLAND DITCH (1100702) DWR↗☆: Observed p99 daily rate 40.0 cfs (max 40.0) exceeds total decreed absolute 0.4 cfs across 6452 recorded day(s).
• STEVENS & LEITER WELL (1100759) DWR↗☆: Observed p99 daily rate 36.0 cfs (max 36.0) exceeds total decreed absolute 1.1 cfs across 4698 recorded day(s).
• FISH DITCH (1100546) DWR↗☆: Observed p99 daily rate 25.0 cfs (max 25.0) exceeds total decreed absolute 0.2 cfs across 7432 recorded day(s).

Seniority (top structures by decreed rate)

Recent inventory & legal-document changes

• 2026-10-10 — call set: FORT LYON CANAL (39703)
• 2026-10-10 — call set: JOHN MARTIN RESERVOIR (39705)
• 2026-10-10 — call released: 39701
• 2026-10-10 — call released: 39694
• 2026-10-09 — call set: FORT LYON CANAL (39701)
• 2026-10-09 — call released: 39660
• 2026-10-09 — call released: 39675
• 2026-10-09 — call released: 39659

Water-court filings this month (division-wide)

3 applications 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 (17 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.

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.