Arkansas: Headwaters to Salida

Division 2 · Water District 11 · As of 2026-08-19 03:34 MDT

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Arkansas: Headwaters to Salida on the ground — the ditches, wells, reservoirs and gages of Water District 11 · clicktap anything for its record

Snowpack — no snow on the ground at 2 SNOTEL sites — normal for the date; the snow year begins in October and typically peaks around April 19. Runoff outlook — Chalk Ck nr Nathrop: even odds of at least 7 kAF over 06-01 to 09-30 — 43% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — Arkansas R at Salida: even odds of at least 68 kAF over 06-01 to 09-30 — 35% 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
Brumley	10570	0.0	0.0	—	April 19 (11.8 in)
Saint Elmo	10420	0.1	0.0	—	April 9 (11.5 in)

Chalk Ck nr Nathrop — 06-01 to 09-30 volume, thousand acre-feet (chance the volume is AT LEAST this):

90%	70%	50%	30%	10%	Normal
2	5	7	10	13	17

Arkansas R at Salida — 06-01 to 09-30 volume, thousand acre-feet (chance the volume is AT LEAST this):

90%	70%	50%	30%	10%	Normal
30	53	68	83	106	197

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: 8 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, 19 agree. Know this water? Tell us →

Stream	This site routes it to	DWR routes it to
Chalk Creek	the mainstem	Delmonica Gulch
West Tennessee Creek	the mainstem	Tennessee Creek
Longs Gulch	the mainstem	Tennessee Creek
Middle Cottonwood Creek	the mainstem	Cottonwood Creek
South Cottonwood Creek	the mainstem	Cottonwood Creek
North Cottonwood Creek	the mainstem	Cottonwood Creek
Browns Creek	the mainstem	Stumpy Creek
Box Creek	the mainstem	Poncha Creek

Sizable streams DWR maps here that this network does not carry:

Lake Fork (14 mi) · Lake Creek (14 mi) · Clear Creek (13 mi) · Pine Creek (12 mi) · Iowa Gulch (11 mi) · Big Union Creek (11 mi) · Fourmile Creek (10 mi) · Tennessee Creek (10 mi)

Reconstruct conditions as of

Evolution of the network

This year, in context

In the weeks around 2026-07-06 (the newest reading on file), flows at the 39 ranked gages are running at a median 15% of their own long-term norm for this window — 37 below a typical year, 2 at or above. Driest relative to its record: COLUMBINE DITCH NEAR FREMONT PASS, CO., ranking 1st lowest of 78 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 19:26 from 62 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 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.

Gage	Trend	Change / decade cfs · % of median annual flow	Significance	Years	Changepoint
▸ ⇆ Busk-Ivanhoe Tunnel BUSTUNCO	↓ decreasing	-0.90 cfs -13.5%	p<0.001	61	~1986
▸ Homestake-Otero Pumps near Granite HOMOTECO	↑ increasing	+42.00 cfs +94.8%	p=0.009	8	—
▸ ⚠️ ⇆ Charles H. Boustead Tunnel BOUTUNCO	↑ increasing	+6.14 cfs +8.2%	p=0.026	54	—
▸ ⚠️ Lake Fork Creek below Sugar Loaf Dam near Leadville LFCBSLCO	↓ decreasing	-8.60 cfs -58.1%	p=0.035	56	~1986
▸ ⇆ Columbine Ditch near Fremont Pass COLDITCO	no clear trend	+0.08 cfs +3.5%	p=0.102	75	~1964
▸ Arkansas River at Granite ARKGRNCO	no clear trend	+4.97 cfs +1.4%	p=0.203	114	~1945
▸ ⚠️ Larkspur Ditch at Marshall Pass LARDITCO	no clear trend	+0.02 cfs	p=0.562	57	~2005

⚠️ 3 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.

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 0 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 †.

Decade	Gages with data (median yr)	Structures reporting (median yr)
1900s	1	0
1910s	8	0
1920s	4	0
1930s	4	0
1940s	4	0
1950s	14	1
1960s	17	0
1970s	25	110
1980s	22	110
1990s	26	170
2000s	28	188
2010s	36	212
2020s	40	109

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 3% of 4627 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=-0.42) -- 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=-0.59) -- 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=-0.58) -- 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 2026-07-06)

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.

1113446 (diversion): +3.5 cfs (6% of that reach's correction)
1114029 (diversion): +3.5 cfs (6% of that reach's correction)
GOLDCAMP SPRING PIPELINE (return): +3.5 cfs (6% of that reach's correction)
1113447 (diversion): +3.5 cfs (6% of that reach's correction)
1113939 (diversion): +3.5 cfs (6% of that reach's correction)
1113349 (diversion): +3.5 cfs (6% of that reach's correction)
1113348 (diversion): +3.5 cfs (6% of that reach's correction)
LANGHOFF DITCH (diversion): +3.5 cfs (6% of that reach's correction)
1114004 (diversion): +3.5 cfs (6% of that reach's correction)
1113956 (diversion): +3.5 cfs (6% 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 1035 day(s) old (DWR publishes ~1 year in arrears)
structure coverage	sparse	3% of schematic structures have data

Independent check: PASS — 100.0000% agreement across 133,957 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 — 99.82% day-level agreement with USGS's own published records for the same gages, across 29 co-listed station(s) and 281,373 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.

62 gage(s) / 709,115 daily values (1909-10-01–2026-07-06); 419 structure(s) with diversion records; 1489 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.

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

What is being counted

Observation wells and pumping wells are different populations and are never conflated: water levels come from monitored observation wells, and metered pumping comes from administered wells reporting through diversion records. Click any well to chart its own record.

Well map

3D aquifer x-ray

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

How the surfaces are built, and what they are not

Alluvial water table on top, Denver Basin members (Dawson, Denver, Arapahoe, Laramie–Fox Hills) stacked beneath where measured, interpolated from measured water levels. Units are never mixed; a surface exists only inside its own unit's well coverage, with no extrapolation; thin epochs are suppressed and say why. Vertical scale is exaggerated for readability and z is head elevation in feet. These are measured heads, not a calibrated groundwater model.

Water-table trends

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

Fastest-declining wells	Setting	ft / decade	Span	p
▸ SC01108018AAA	unknown	-12.48	18 yr	0.0
▸ NA05000814DCB	alluvial	-4.89	24 yr	0.0001
▸ SC01507834CCD	alluvial	-2.32	36 yr	0.0
▸ SC01407830DAA	unknown	-2.24	54 yr	0.0
▸ NA05100833AAD	alluvial	-2.06	44 yr	0.0
▸ NA05000835AAD	alluvial	-1.89	54 yr	0.0001
▸ NA05000733DAB	alluvial	-1.87	45 yr	0.0007
▸ SC00908032ACD	alluvial	-0.47	44 yr	0.0055

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.

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.

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).

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)
▸ BEAR LAKE (CHAFFEE CTY) MIN LEVEL (1103927)	102,989	1979-10-31	—	—	dossier →
▸ TURQUOISE RESERVOIR (1103500)	95,794	2018-01-23	—	—	dossier →
▸ TWIN LAKES RESERVOIR (1103503)	80,503	1984-10-31	—	—	dossier →
▸ CLEAR CREEK RESERVOIR (1103504)	8,164	2018-04-30	—	—	dossier →
▸ NORTH FORK RESERVOIR (1103300)	583	2010-10-31	—	—	dossier →
▸ O'HAVER RESERVOIR (1103921)	168	2010-09-30	—	—	dossier →
▸ COTTONWOOD LAKE (1104005)	102	2010-10-31	—	—	dossier →
▸ RAINBOW LAKE (M COTTONWD CRK) (1103535)	59	2010-10-31	—	—	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
Brumley	10570	0.0	0.0	—	April 19 (11.8 in)
Saint Elmo	10420	0.1	0.0	—	April 9 (11.5 in)

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

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

A bad snow year here comes in two flavors (both called snow drought), 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. This year was one of the dry ones: the pack peaked at 48% of median.

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 →

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	5	7	10	13	17

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 22 kAF so far this period (partial record: 36 of 93 days). 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 43 replayed seasons (16% typical miss unadjusted vs 17% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

90% chance of at least	70% chance of at least	50% chance of at least	30% chance of at least	10% chance of at least	Normal	Observed
30	53	68	83	106	197	22*

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 (1981–2025)

Across 45 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 66% of a normal season (a snow-to-runoff elasticity of 1.1).

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

Right now

This is the 1st-driest week 27 in 117 years of record at ARKANSAS RIVER AT SALIDA, CO. (as of 2026-06-29; this week’s flow sits at the 1st percentile for the date). On this week’s US Drought Monitor, Saguache County is 40% in D4 exceptional drought (2026-08-25). The law agrees: the most senior active call leaves 95% 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.

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 (538 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	2025-09-29 → 2026-02-23	21	27th (2025-10-13)	not yet
the 2020-22 drought	2021-03-15 → 2022-04-04	55	18th (2021-12-13)	0 weeks
the 2018 drought	2018-08-27 → 2019-05-27	39	5th (2018-12-03)	2 weeks
the 2012-13 drought	2012-08-13 → 2013-12-02	68	5th (2012-11-19)	2 weeks
unnamed dry spell	2004-08-16 → 2005-12-26	71	15th (2005-02-21)	4 weeks
the 2002 drought	2002-07-22 → 2004-03-01	84	2nd (2002-12-02)	4 weeks
unnamed dry spell	1990-04-30 → 1990-12-03	31	21st (1990-05-28)	5 weeks
unnamed dry spell	1988-10-10 → 1989-03-06	21	23rd (1988-11-14)	5 weeks
the 1981 drought	1981-05-25 → 1981-12-07	28	13th (1981-07-13)	6 weeks
unnamed dry spell	1978-12-11 → 1979-07-23	32	7th (1979-03-05)	0 weeks
the 1977 drought	1977-04-11 → 1978-09-11	74	2nd (1978-03-20)	43 weeks
unnamed dry spell	1975-02-03 → 1975-08-18	28	21st (1975-04-07)	0 weeks
unnamed dry spell	1973-01-29 → 1973-09-03	31	16th (1973-05-07)	0 weeks
unnamed dry spell	1959-01-19 → 1959-11-23	44	17th (1959-03-30)	35 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 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 (1,321 rights across 118 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is -0.03 — 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 1860-05-01 to 2022-11-03. 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: 1934 across 1489 structure(s); 311 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 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	365	419	1866-05-01
2015	365	222	1865-10-07
2016	366	355	1862-04-30
2017	365	260	1866-10-31
2018	365	401	1862-04-30
2019	365	389	1862-03-20
2020	366	340	1861-05-31
2021	365	362	1862-04-30
2022	365	370	1862-11-15
2023	365	369	1862-04-30
2024	366	359	1862-04-30
2025	365	384	1862-04-30

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

MUNDLEIN DITCH NO 1 (1100557) DWR↗ stopped 2023-10-18 (8+ days) — call at CHILILI DITCH curtailing 100% of its decreed rate [heuristic-strong]
RIVERSIDE-ALLEN DITCH (1100534) DWR↗ stopped 2023-10-15 (16+ days) — call at CHILILI DITCH curtailing 100% of its decreed rate [heuristic-strong]
TENASSEE DITCH (1100551) DWR↗ stopped 2023-10-09 (16+ days) — call at BUTTE VALLEY DITCH curtailing 100% of its decreed rate [heuristic-strong]
DEL MONTE IRRIG DITCH (1100548) DWR↗ stopped 2023-10-08 (8+ days) — call at BUTTE VALLEY DITCH curtailing 100% of its decreed rate [heuristic-strong]
NOLAND DITCH (1100555) DWR↗ stopped 2023-10-08 (10+ days) — call at BUTTE VALLEY 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
MT ELBERT CONDUIT (1101123) DWR↗	1939-02-10	0.0% / 0.0%	0.0% / 0.0%
HALFMOON DIVERSION (1102057) DWR↗	1881-05-07	0.0% / 0.0%	0.0% / 0.0%
D & C PIPELINE NO 3 (1100887) DWR↗	1908-07-05	0.0% / 0.0%	0.0% / 0.0%
SETHMAN PIPELINE HDGT 1 (1100804) DWR↗	1904-06-01	0.0% / 0.0%	0.0% / 0.0%
MISSOURI PARK DITCH (1100570) DWR↗	1880-11-15	0.0% / 0.0%	0.0% / 0.0%
STARR DITCH (LOWER PT) (1100786) DWR↗	1860-05-01	100.0% / 100.0%	100.0% / 100.0%
BOWEN DITCH (1100691) DWR↗	1888-09-24	0.0% / 0.0%	0.0% / 0.0%
SUNNYSIDE PARK DITCH (1100539) DWR↗	1884-01-03	0.0% / 0.0%	0.0% / 0.0%
HELENA DITCH (1100535) DWR↗	1882-03-01	0.0% / 0.0%	0.0% / 0.0%
PIONEER DITCH (BROWNS) (1100632) DWR↗	1866-05-17	27.1% / 0.0%	0.0% / 0.0%
RIVERSIDE-ALLEN DITCH (1100534) DWR↗	1872-11-01	0.0% / 0.0%	0.0% / 0.0%
STEVENS & LEITER DITCH (1100751) DWR↗	1873-09-01	0.0% / 0.0%	0.0% / 0.0%

Abandonment radar (25 screens)

Absolute rights with 10+ years of no recorded diversions. Screens only — storage, alternate points, and plan operations can explain nonuse lawfully. And diversion REPORTING itself only reached its modern level ~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 — 109 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 — 109 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 — 109 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 — 108 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 — 108 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 — 108 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 — 108 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 — 108 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 — 108 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 — 108 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 260 of 1489 structures with rights (281 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 804.3 cfs (max 1260.9) exceeds total decreed absolute 3.0 cfs across 12875 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 10598 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 7630 recorded day(s).
BUSK-IVANHOE SYSTEM (1104612) DWR↗: Observed p99 daily rate 49.6 cfs (max 74.7) exceeds total decreed absolute 17.5 cfs across 13026 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 16496 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)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Conditional?
MT ELBERT CONDUIT (1101123) DWR↗	1939-02-10	1	370.0	—
HALFMOON DIVERSION (1102057) DWR↗	1881-05-07	4	150.0	—
D & C PIPELINE NO 3 (1100887) DWR↗	1908-07-05	1	72.8	—
SETHMAN PIPELINE HDGT 1 (1100804) DWR↗	1904-06-01	1	63.8	—
MISSOURI PARK DITCH (1100570) DWR↗	1880-11-15	3	55.0	—
STARR DITCH (LOWER PT) (1100786) DWR↗	1860-05-01	1	51.0	—
BOWEN DITCH (1100691) DWR↗	1888-09-24	1	44.5	—
SUNNYSIDE PARK DITCH (1100539) DWR↗	1884-01-03	3	39.2	—
HELENA DITCH (1100535) DWR↗	1882-03-01	3	36.0	—
PIONEER DITCH (BROWNS) (1100632) DWR↗	1866-05-17	3	31.0	—
RIVERSIDE-ALLEN DITCH (1100534) DWR↗	1872-11-01	4	29.0	—
STEVENS & LEITER DITCH (1100751) DWR↗	1873-09-01	1	27.6	—
WILLOWDALE DITCH (1100684) DWR↗	1867-05-31	9	24.9	—
WOLF & NEERLAND DITCH (1100651) DWR↗	1877-04-01	6	21.4	—
NEW SALIDA DITCH (1100536) DWR↗	1882-05-01	1	20.0	—

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

Water-court filings this month (division-wide)

6 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 (30 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 6 filings, with excerpts

Case	What it asks	County	Excerpt
`2026CW3032`	—	—	CASE NO. 2026CW3032; Previous Case Nos. 20CW3003, 13CW3008, 97CW83 – EMPIRE LODGE HOMEOWNER’S ASSOCIATION, INC. c/o Tim Ratterman, President, 585 Empire Valley Drive, Leadville, CO 80461 (Please address all pleadings and inquiries regarding this matter to Appl…
`2026CW3033` 1205090 1205091	reasonable diligence	—	CASE NO. 2026CW3033; Previous Case No. 2019CW3032 – SANGRE DE CRISTO RANCH, LLC c/o Stephanie Stolba, 44301 E Iliff Trail, Bennett, CO 80102 (Please address all pleadings and inquiries regarding this matter to Applicant’s attorney: Jennifer M. DiLalla, #40319,…
`2026CW3034`	—	HUERFANO	CASE NO. 2026CW 3034; (2017CW3075); CUCHARAS SANITATION & WATER DISTRICT, 16925 Highway 12, Cucharas, Colorado 81055 (“CSWD”); Huerfano County Water Conservancy District, c/o/ Administrator, P.O. Pox 442, La Veta, Colorado 81055 (“Huerfano”); Town of La Veta, …
`2026CW3035`	plan for augmentation	—	CASE NO. 2026CW3035; GUM FAMILY TRUST AND JACOB GUM, TRUSTEE AND INDIVIDUALLY, 8580 Forest Line Point, Colorado Springs, CO, 80908 (Please address all pleadings a nd inquiries regarding this matter to Applicant’s attorney s: Philip E. Lopez, Eric K. Trout, Fai…
`2026CW3036` 1406622 1406637 1406670	plan for augmentation	—	CASE NO. 2026CW3036; Previous Case No. 2017CW3009 – SILOAM WELL ASSOCIATION, 46 Glenroyal Dr., Pueblo, CO 81005 (Please address all pleadings and inquiries regarding this matter to Applicant’s attorney: Steven L. Jasnssen, Esq., 1937 Juniper St., Longmont, CO …
`2026CW7`	—	—	CASE NO. 2026CW7; COLORADO DIVISION OF PARKS AND WILDLIFE AND THE PARKS AND WILDLIFE COMMISSION (“CPW”), Attn: Pete Conovitz, Water Rights Program Administrator, 6060 Broadway, Denver, Colorado 80216 (Please address all pleadings and inquiries regarding this m…

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
LAVWCD LARKSPUR DITCH	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2026-03-31	1107127	plan file
BOX CREEK PLACER MINE COMBINED SITES	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2026-04-30	1107821	plan file
WILLOW CREEK MINE ON CORSKE CREEK	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2027-02-28	1107819	plan file
BARN POND	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2027-04-30	1107136	plan file
CPW HARRINGTON DITCH	37-92-308(4) PLAN PENDING COURT APPLICATION	Pending	—	1107128	plan file
LEADVILLE NATIONAL FISH HATCHERY GROUNDWATER WELL	37-92-308(5) PLANS LESS THAN 5 YEARS	Additional Info Needed	—	1107137	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.

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

Administration number

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

Stream	Gage	R-mile	Predicted (cfs)	Observed (cfs)	Δ (cfs)	Reach (mi)	Hypothesis
MAINSTEM	PONCHA CREEK AT PONCHA SPRINGS (PNCKPSCO)	321.8	253.9	2.0	-251.9	240.7	Unaccounted -251.9 cfs loss over 240.7 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	ARKANSAS RIVER NEAR NATHROP, CO (ARKNATCO)	63.8	0.0	208.0	+208.0	4.8	Unaccounted +208.0 cfs gain over 4.8 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	COTTONWOOD CREEK NEAR BUENA VISTA (COCRBVCO)	48.3	147.7	3.3	-144.4	13.3	Unaccounted -144.4 cfs loss over 13.3 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	ARKANSAS RIVER BELOW GRANITE, CO (ARKBGNCO)	35.0	7.5	147.7	+140.2	0.9	Unaccounted +140.2 cfs gain over 0.9 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	CLEAR CREEK ABOVE CLEAR CREEK RESERVOIR, CO. (CCACCRCO)	31.0	100.8	23.7	-77.1	1.1	Unaccounted -77.1 cfs loss over 1.1 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	ARKANSAS RIVER NEAR WELLSVILLE, CO. (ARKWELCO)	81.1	197.3	253.9	+56.6	5.6	Unaccounted +56.6 cfs gain over 5.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	ARKANSAS RIVER AT GRANITE, CO. (ARKGRNCO)	29.9	46.8	100.8	+54.1	3.3	Unaccounted +54.1 cfs gain over 3.3 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	ARKANSAS RIVER BELOW EMPIRE GULCH NEAR MALTA, CO (ARKEMPCO)	20.1	3.1	43.1	+40.0	7.7	Unaccounted +40.0 cfs gain over 7.7 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	LARKSPUR DITCH AT MARSHALL PASS (LARDITCO)	59.0	17.7	0.0	-17.7	3.9	Unaccounted -17.7 cfs loss over 3.9 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	PINE CREEK AT MOUTH (PINMOUCO)	34.1	23.7	7.5	-16.2	3.1	Unaccounted -16.2 cfs loss over 3.1 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	LAKE CREEK BELOW TWIN LAKES RESERVOIR (LAKBTLCO)	26.6	32.4	46.8	+14.4	6.0	Unaccounted +14.4 cfs gain over 6.0 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	CHALK CREEK AT NATHROP (CHCRNACO)	55.1	3.8	17.7	+13.9	1.4	Unaccounted +13.9 cfs gain over 1.4 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	COTTONWOOD CREEK BELOW HOT SPRINGS (COCRHSCO)	359.4	9.2	22.9	+13.7	2.7	Unaccounted +13.7 cfs gain over 2.7 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	ARKANSAS RIVER NEAR LEADVILLE, CO (ARKLEACO)	12.2	0.0	11.9	+11.9	12.2	Unaccounted +11.9 cfs gain over 12.2 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	NORTH FORK SOUTH ARKANSAS RIVER (NFSOAKCO)	360.2	22.9	11.4	-11.5	0.8	Unaccounted -11.5 cfs loss over 0.8 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	PUEBLO WEST PIONEER (BROWN) AUGMENTATION STATION (PWPBASCO)	368.1	11.4	0.6	-10.8	7.9	Unaccounted -10.8 cfs loss over 7.9 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	CLEAR CREEK BELOW CLEAR CREEK RESERVOIR (CCBCCRCO)	20.6	43.1	32.4	-10.7	0.5	Unaccounted -10.7 cfs loss over 0.5 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	ARKANSAS RIVER AT SALIDA, CO. (ARKSALCO)	75.5	208.0	197.3	-10.7	11.7	Unaccounted -10.7 cfs loss over 11.7 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	SOUTH ARKANSAS RIVER BELOW GARFIELD (SOARGRCO)	356.7	0.2	9.2	+9.0	3.5	Unaccounted +9.0 cfs gain over 3.5 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	LAKE FORK CREEK BELOW SUGAR LOAF DAM NEAR LEADVILLE (LFCBSLCO)	12.4	11.9	3.1	-8.8	0.2	Unaccounted -8.8 cfs loss over 0.2 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	EF ARKANSAS R AT US HIGHWAY 24, NR LEADVILLE, CO. (ARKEFOCO)	371.2	1.9	10.3	+8.3	2.6	Unaccounted +8.3 cfs gain over 2.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	BROWNS CREEK ABOVE CONFLUENCE OF ARKANSAS (BCACOACO)	373.2	10.7	2.6	-8.1	1.1	Unaccounted -8.1 cfs loss over 1.1 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.

Gage ⇅	Station ⇅	Avg cfs Aug 10–Aug 16 ⇅	% Hist Median ⇅	Rank ⇅	Δ1wk ⇅	Δ4wk ⇅	Yrs ⇅	Status ⇅
SOARGRCO	SOUTH ARKANSAS RIVER BELOW GARFIELD	9.2	42%	0	+0	+0	9.9	STALE
LKCTURCO	LAKE FORK CREEK ABOVE TURQUOISE	2.3	30%	0	+0	-0	29.1	SHORT_RECORD
ARKEMPCO	ARKANSAS RIVER BELOW EMPIRE GULCH NEAR MALTA, CO	43.1	36%	0	+7	-1	11.2	SHORT_RECORD
ARKBGNCO	ARKANSAS RIVER BELOW GRANITE, CO	147.7	32%	0	+46	+45	13.9	SHORT_RECORD
COCRHSCO	COTTONWOOD CREEK BELOW HOT SPRINGS	22.9	53%	0	+1	-1	12.3	SHORT_RECORD
PNCKPSCO	PONCHA CREEK AT PONCHA SPRINGS	2.0	33%	0	+1	-2	10.9	SHORT_RECORD
SOAKNBCO	SOUTH ARKANSAS ABOVE NEWBY BORING DITCH	8.9	54%	0	-5	-2	6.3	SHORT_RECORD
DD3AUGCO	DERRY DITCH NO 3 AUGMENTATION	0.0	0%	0	+0	+0	5.7	SHORT_RECORD
GYCROHCO	GRAY'S CREEK BELOW O'HAVER RESERVOIR	0.7	50%	6	+0	-0	13.2	SHORT_RECORD
NFSOAKCO	NORTH FORK SOUTH ARKANSAS RIVER	11.4	55%	7	+1	+2	10.2	SHORT_RECORD
PINMOUCO	PINE CREEK AT MOUTH	7.5	75%	19	+0	-0	7.3	SHORT_RECORD
PWWDASCO	PUEBLO WEST COMBINED AUGMENTATION STATION NEAR WILLOWDALE HEADGATE	3.8	59%	33	-0	+0	12.2	SHORT_RECORD
HRGTNDCO	HARRINGTON DITCH	1.9	0%	50	-0	-0	0.2	SHORT_RECORD
BCACOACO	BROWNS CREEK ABOVE CONFLUENCE OF ARKANSAS	2.6	145%	55	+1	+2	3.2	SHORT_RECORD
PWPBASCO	PUEBLO WEST PIONEER (BROWN) AUGMENTATION STATION	0.6	6689%	57	+1	+1	7.7	SHORT_RECORD
SOAKTECO	SOUTH ARKANSAS BELOW TENNASSE DITCH	10.7	117%	59	-5	-4	16.2	SHORT_RECORD
BLKRSOCO	BOSS LAKE RESERVOIR OUTLET	0.2	348%	100	+0	+0	12.1	SHORT_RECORD
BUSTUNCO	BUSK-IVANHOE TUNNEL	0.1	5%	0	-0	-0	69.5	OK
LAKBTLCO	LAKE CREEK BELOW TWIN LAKES RESERVOIR	46.8	20%	0	+20	+28	57.7	OK
LARDITCO	LARKSPUR DITCH AT MARSHALL PASS	0.0	0%	0	+0	+0	63.9	OK
LFCBSLCO	LAKE FORK CREEK BELOW SUGAR LOAF DAM NEAR LEADVILLE	3.1	20%	0	+0	-1	56.8	OK
HOMTUNCO	HOMESTAKE TUNNEL	0.0	0%	0	+0	+0	59.7	OK
ARKEFOCO	EF ARKANSAS R AT US HIGHWAY 24, NR LEADVILLE, CO.	10.3	30%	0	-0	+1	36.2	OK
ARKLEACO	ARKANSAS RIVER NEAR LEADVILLE, CO	11.9	24%	0	+1	+0	52.2	OK
HALMALCO	HALFMOON CREEK NEAR MALTA, CO	7.6	28%	0	+0	-0	79.9	OK
LAKATLCO	LAKE CREEK ABOVE TWIN LAKES RESERVOIR, CO.	26.0	26%	0	-2	-5	78.3	OK
ARKGRNCO	ARKANSAS RIVER AT GRANITE, CO.	100.8	23%	0	+33	+36	115.8	OK
CCACCRCO	CLEAR CREEK ABOVE CLEAR CREEK RESERVOIR, CO.	23.7	39%	0	-2	-0	80.1	OK
ARKNATCO	ARKANSAS RIVER NEAR NATHROP, CO	208.0	30%	0	+26	+32	39.2	OK
ARKSALCO	ARKANSAS RIVER AT SALIDA, CO.	197.3	28%	0	+13	+6	116.8	OK
ARKWELCO	ARKANSAS RIVER NEAR WELLSVILLE, CO.	253.9	35%	0	+33	+33	65.2	OK
COLDITCO	COLUMBINE DITCH NEAR FREMONT PASS, CO.	0.0	0%	0	+0	+0	77.3	OK
EWIDITCO	EWING DITCH AT TENNESSEE PASS, CO.	0.0	0%	0	+0	+0	73.2	OK
WURDITCO	WURTZ DITCH NEAR TENNESSEE PASS	0.0	0%	0	+0	+0	78.5	OK
WUREXTCO	WURTZ EXTENSION	0.0	0%	0	+0	+0	35.0	OK
BOUTUNCO	CHARLES H. BOUSTEAD TUNNEL	0.0	0%	0	-0	-3	54.8	OK
CCBCCRCO	CLEAR CREEK BELOW CLEAR CREEK RESERVOIR	32.4	46%	8	+4	+7	53.6	OK
CHCRNACO	CHALK CREEK AT NATHROP	17.7	43%	10	+3	+5	55.6	OK
COCRBVCO	COTTONWOOD CREEK NEAR BUENA VISTA	3.3	42%	27	-5	+2	51.6	OK
TWITUNCO	TWIN LAKES TUNNEL	6.4	24%	30	-0	-3	90.9	OK