Big Thompson River

Division 1 · Water District 4 · As of 2026-08-26 11:11 MDT

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Big Thompson River on the ground — the ditches, wells, reservoirs and gages of Water District 4 · 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 27. Runoff outlook — Big Thompson R at Canyon Mouth: even odds of at least 48 kAF over 06-01 to 09-30 — 61% 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
Bear Lake	9490	0.3	0.0	—	April 27 (19.8 in)
Willow Park	10710	0.0	0.0	—	April 29 (21.0 in)

Big Thompson R at Canyon Mouth — 06-01 to 09-30 volume, thousand acre-feet (chance the volume is AT LEAST this):

90%	70%	50%	30%	10%	Normal
38	43	48	53	62	79

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: 9 parent disagreements, 9 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 23 streams, 14 agree. Know this water? Tell us →

Stream	This site routes it to	DWR routes it to
Twin Sisters Creek	the mainstem	West Fork Little Thompson River
North Fork Fish Creek	the mainstem	Fish Creek
Fish Creek	the mainstem	Buckhorn Creek
Stove Prairie Creek	the mainstem	Buckhorn Creek
Dry Creek	the mainstem	Cedar Creek
Wind River	the mainstem	Aspen Brook
Dry Creek	the mainstem	Little Thompson River
Dry Creek	the mainstem	Little Thompson River

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

Cedar Creek (11 mi) · Glacier Creek (10 mi) · Ryan Gulch (6 mi) · Dry Gulch (5 mi) · Thornton Gulch (5 mi) · Hayden Creek (4 mi) · Aspen Brook (4 mi) · Spruce Creek (4 mi)

Reconstruct conditions as of

Evolution of the network

This year, in context

In the weeks around 2026-08-15 (the newest reading on file), flows at the 49 ranked gages are running at a median 64% of their own long-term norm for this window — 38 below a typical year, 11 at or above. Driest relative to its record: BOULDER-LARIMER DITCH NEAR BERTHOUD, ranking 1st lowest of 27 years.

How this comparison is made

Each gage's mean flow over the 3 days either side of 2026-08-15, 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 19:16 from 72 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 72 gages with enough record, 10 are trending down and 5 up, and 11 carry a detected shift. The clearest is Saint Vrain Supply Canal T.O. to L. Thompson River, its annual mean flow changing -1.86 cfs per decade (-40.1% of its median annual flow) over 43 years (p<0.0001). The other 56 show no clear signal either way.

What drought has cost here

Since 1991, federal crop insurance has paid $38,748,835 in drought-caused claims across Boulder, Larimer, Weld counties — 15.2% of all insured crop losses there. The worst year was 2022 ($8,829,713).

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.

Gage	Trend	Change / decade cfs · % of median annual flow	Significance	Years	Changepoint
▸ Saint Vrain Supply Canal T.O. to L. Thompson River SVSLT1CO	↓ decreasing	-1.86 cfs -40.1%	p<0.001	43	~1966
▸ Big Thompson River Bl Powerhouse, near Drake BTBLOVCO	↓ decreasing	-18.21 cfs -13.3%	p<0.001	63	~1953
▸ ⚠️ Saint Vrain Supply Canal to Hertha Creek SVSHERCO	↑ increasing	+0.17 cfs	p<0.001	43	~1983
▸ Big Thompson River at Mouth of Canyon near Drake BTCANYCO	↓ decreasing	-15.56 cfs -15.9%	p<0.001	81	~1958
▸ Miner Longan Ditch MILDITCO	↓ decreasing	-1.47 cfs -115.9%	p=0.003	14	~2017
▸ South Side Ditch SOSDITCO	↓ decreasing	-1.55 cfs -37.5%	p=0.006	13	—
▸ Reorganized Farmers Ditch REODITCO	↓ decreasing	-3.80 cfs -46.2%	p=0.012	14	~2017
▸ Charles Hansen Feeder Canal below Big Thompson Siphon HFCBBSCO	↑ increasing	+4.94 cfs +3.1%	p=0.019	75	—
▸ Hill and Brush Ditch HIBDITCO	↓ decreasing	-0.96 cfs -39.8%	p=0.023	15	—
▸ Dille Tunnel near Drake DILTUNCO	↑ increasing	+2.90 cfs +11.7%	p=0.027	75	~1982
▸ Evanstown Ditch EVADITCO	↓ decreasing	-5.51 cfs -54.1%	p=0.029	12	—
▸ USBR Power Plant at Big Thompson Canyon Mouth BTPPMCCO	↓ decreasing	-17.34 cfs -21.4%	p=0.030	25	~2011
▸ Glacier Creek near Estes Park GLAESTCO	↑ increasing	+6.62 cfs +21.6%	p=0.036	17	—
▸ Big Thompson River at Mouth near La Salle BIGLASCO	↑ increasing	+3.53 cfs +5.4%	p=0.039	100	~1956
▸ Big Thompson River above Lake Estes BTABESCO	↓ decreasing	-4.38 cfs -3.4%	p=0.044	75	~1965
▸ Big Thompson River below Lake Estes BTBLESCO	no clear trend	-3.92 cfs -4.4%	p=0.273	96	~1953

⚠️ 1 gage 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.

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

How the measurement network itself changed

This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 51 gage(s) and 123 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1994. 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)
1910s	1	0
1920s	1	0
1930s	4	0
1940s	5	0
1950s	19	38
1960s	19	34
1970s	15	37
1980s	16	41
1990s	22	64
2000s	26	74
2010s	48	74
2020s	51	109

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 5% of 1751 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 (5701 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.

HANSEN FEEDER CANAL LOVELAND TURNOUT: reach shifted from -172 cfs to -21 cfs summer mean (more gaining, p=0.000, 26 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
USBR POWER PLANT AT BIG THOMPSON CANYON MOUTH: reach shifted from +221 cfs to +117 cfs summer mean (more losing, p=0.006, 30 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
MINER LONGAN DITCH: reach shifted from -143 cfs to -135 cfs summer mean (more gaining, p=0.043, 11 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
RYANS GULCH EXCHANGE DITCH: reach shifted from -60 cfs to -17 cfs summer mean (more gaining, p=0.001, 17 yr) [sedimentary plains/foothills: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]
WIND RIVER NEAR ESTES PARK: reach shifted from +185 cfs to -41 cfs summer mean (more losing, p=0.009, 65 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=-0.49) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
BIG THOMPSON RIVER AT MOUTH OF CANYON NEAR DRAKE: reach shifted from +222 cfs to -61 cfs summer mean (more losing, p=0.000, 63 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=-0.52) -- part of it may be unaccounted water becoming accounted, not hydrologic change]

Groundwater now has its own tab: 91 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 38 reservoir(s), end-of-year storage back to 1950, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 79-year window with full coverage (1948–2026), the dominant shared pattern across 3 gage(s) explains 45% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

BTBLESCO 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 2026-08-15)

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.

LARIMER CO SPRING E (return): +20.5 cfs (17% of that reach's correction)
LARIMER CO SPRING F (return): +20.5 cfs (17% of that reach's correction)
DILLE TUNNEL (diversion): +20.5 cfs (17% of that reach's correction)
ARKINS SUPPLY CNL (diversion): +20.5 cfs (17% of that reach's correction)
HANSEN FEEDER CNL PUMP (diversion): +20.5 cfs (17% of that reach's correction)
HANDY DITCH (diversion): +20.5 cfs (17% of that reach's correction)
FT MORGAN OUTING CLUB PL (diversion): +1.4 cfs (20% of that reach's correction)
ESTES PARK DITCH 1 (diversion): +1.4 cfs (20% of that reach's correction)
LAKE ESTES (diversion): +1.4 cfs (20% of that reach's correction)
ESTES PARK DITCH 4 (diversion): +1.4 cfs (20% 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 15 day(s) old (target 7)
diversion record	stale	newest diversion record is 669 day(s) old (DWR publishes ~1 year in arrears)
structure coverage	sparse	5% of schematic structures have data

Independent check: PASS — 100.0000% agreement across 491,920 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 — 99.70% day-level agreement with USGS's own published records for the same gages, across 19 co-listed station(s) and 179,779 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.

72 gage(s) / 798,554 daily values (1914-04-01–2026-08-15); 284 structure(s) with diversion records; 1296 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.

6,963 water-level measurements across 91 monitored well(s) — 60 alluvial, 5 bedrock — plus 16 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 4 well(s) with enough record for a trend test: 4 declining, 0 rising.

Fastest-declining wells	Setting	ft / decade	Span	p
▸ LSP-040 DSS02MLK	alluvial	-1.85	22 yr	0.0
▸ SB00406711DCC	alluvial	-1.53	41 yr	0.0031
▸ SB00506816ABA	unknown	-0.79	38 yr	0.0068
▸ SB00506817AAB	alluvial	-0.53	45 yr	0.0017

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.

MINER LONGAN DITCH: 1 alluvial well(s) nearby. Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

RYANS GULCH EXCHANGE DITCH: 6 alluvial well(s) nearby. Glover screen: 0.2 cfs of nearby metered alluvial pumping → est. lagged depletion 0.1–0.2 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

WIND RIVER NEAR ESTES PARK: 0 alluvial well(s) nearby. Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

BIG THOMPSON RIVER BELOW HILLSBOROUGH DIVERSION: 6 alluvial well(s) nearby; pooled water table -2.2 ft (1941–1986, decreasing, p=0.0017)

BIG THOMPSON RIVER ABOVE LAKE ESTES: 0 alluvial well(s) nearby

BIG THOMPSON RIVER AT LOVELAND, CO.: 5 alluvial well(s) nearby. Glover screen: 0.0 cfs of nearby metered alluvial pumping → est. lagged depletion 0.0–0.0 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

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.

38 reservoir(s) with 16,980 storage measurement(s), 1950–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 139,543 AF across 27 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)
▸ CARTER LAKE RES (0404513)	64,772	2024-10-31	—	—	dossier →
▸ GLACIER RES NO 1 (0404111)	63,966	1980-11-16	—	—	dossier →
▸ BOYD LAKE RES (0404110)	29,668	2024-10-31	—	—	dossier →
▸ DEFRANCE RES (0404114)	22,080	1951-11-01	—	—	dossier →
▸ DRY CREEK RESERVOIR (0403721)	8,869	2024-10-31	—	—	dossier →
▸ LOVELAND MUNICIPAL RES (0403659)	6,804	2024-10-31	—	—	dossier →
▸ LON HAGLER RES (0404136)	4,193	2024-10-31	—	—	dossier →
▸ LONE TREE RES (0404137)	4,036	2024-10-31	—	—	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
Bear Lake	9490	0.3	0.0	—	April 27 (19.8 in)
Willow Park	10710	0.0	0.0	—	April 29 (21.0 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 1 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 70% of median.

The snow never came: 1987, 1991, 1992, 2002, 2012, 2026. The snow left early: 1981.

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 — Big Thompson R at Canyon Mouth

NRCS's final issue (2026-06-01) calls it even odds that at least 48 kAF arrives over 06-01 to 09-30 — 61% of a normal season; almost certainly at least 38, probably not more than 62. 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
38	43	48	53	62	79

How good are these forecasts here? (1951–2012)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 61 seasons: the median miss of the 50% forecast is 78%, with a high bias of 78%, and the observed volume landed inside the stated 10–90% band 16% 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 (1981–2013)

Across 33 measured years, the season’s water has loosely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 44% of a normal season (a snow-to-runoff elasticity of 1.2). In warm, early-melt years the river delivered a median of 41% of a normal season, against 70% 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.

Decreed rights on this network run from 1861-06-01 to 2021-01-29. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 100% of a median irrigation season and 61% in a dry one. 25 abandonment screens and 23 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: 1819 across 1296 structure(s); 0 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 1951–2025, administration on this district has been tightening: 2 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 (75 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	309	220	1873-06-30
2015	329	145	1870-06-01
2016	366	186	1875-06-30
2017	355	269	1881-02-01
2018	365	269	1876-05-10
2019	365	266	1881-02-01
2020	366	195	1869-04-01
2021	349	198	1867-04-15
2022	365	241	1867-04-15
2023	331	229	1869-04-01
2024	366	193	1881-02-01
2025	365	312	1881-02-01

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

GEORGE RIST DITCH (0400520) DWR↗ stopped 2024-10-01 (6+ days) — call at STERLING IRR CO DITCH 1 curtailing 55% of its decreed rate [heuristic-partial, district-confirmed]
BARNES DITCH (0400501) DWR↗ stopped 2024-07-25 (51+ days) — call at STERLING IRR CO DITCH 1 curtailing 99% of its decreed rate [heuristic-partial, district-confirmed]
GEORGE RIST DITCH (0400520) DWR↗ stopped 2024-07-06 (59+ days) — call at STERLING IRR CO DITCH 1 curtailing 88% of its decreed rate [heuristic-partial, district-confirmed]
DILLE TUNNEL (0400540) DWR↗ stopped 2024-06-29 (8+ days) — call at STERLING IRR CO DITCH 1 curtailing 100% of its decreed rate [heuristic-partial, district-confirmed]
LOVELAND GREELEY CANAL (0400532) DWR↗ stopped 2024-05-25 (15+ days) — call at NEW CACHE LA POUDRE CO DITCH curtailing 96% of its decreed rate [heuristic-partial]
GEORGE RIST DITCH (0400520) DWR↗ stopped 2023-11-28 (141+ days) — call at PREWITT INLET CANAL curtailing 55% of its decreed rate [heuristic-partial, district-confirmed]
EVANSTOWN DITCH (0400517) DWR↗ stopped 2023-10-16 (183+ days) — call at LEE STEWART ESKINS DITCH curtailing 100% of its decreed rate [heuristic-strong]
DILLE TUNNEL (0400540) DWR↗ stopped 2023-10-07 (151+ days) — call at STERLING IRR CO DITCH 1 curtailing 51% of its decreed rate [heuristic-partial, district-confirmed]
HANDY DITCH (0400521) DWR↗ stopped 2023-09-13 (218+ days) — call at HARMONY DITCH 1 curtailing 82% of its decreed rate [heuristic-partial, district-confirmed]
HILL BRUSH DITCH (0400522) DWR↗ stopped 2023-09-05 (265+ days) — call at OSBORNE CAYWOOD 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
HANDY DITCH (0400521) DWR↗	1861-11-10	100.0% / 61.2%	6.1% / 0.0%
BARNES DITCH (0400501) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
HOME SUPPLY DITCH (0400524) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
BOULDER LARIMER CO IRR MFG D (0400588) DWR↗	1875-06-30	58.0% / 16.8%	5.6% / 0.0%
LOVELAND GREELEY CANAL (0400532) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
LOUDEN DITCH (0400530) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
DILLE TUNNEL (0400540) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
GEORGE RIST DITCH (0400520) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
OLYMPUS TUNNEL (0401000) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
ESTES PARK FOOTHILLS PL (0400516) DWR↗	1933-09-14	8.2% / 0.0%	8.2% / 0.0%
HILLSBOROUGH DITCH (0400523) DWR↗	1861-11-10	100.0% / 61.2%	5.6% / 0.0%
HOME SUPPLY DITCH DRY CREEK DIVERSION (0400531) DWR↗	1881-07-15	5.6% / 0.0%	5.6% / 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 ~1994 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

COLE WELL 1 (0400672) DWR↗ (1956-04-30, 0.2 cfs decreed): last active 1962 — 62 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
LAWN RES (0404167) DWR↗ (1902-06-10, 0.0 cfs decreed): last active 1980 — 44 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
HERHOLD DITCH (0400706) DWR↗ (1975-03-20, 0.2 cfs decreed): last active 1981 — 43 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
JORDAN WELL 1 (0405006) DWR↗ (1955-07-02, 1.5 cfs decreed): last active 1981 — 43 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
BARTHOLF DITCH 1 (0400568) DWR↗ (1899-06-22, 0.8 cfs decreed): last active 1990 — 34 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
BARTHOLF DITCH 2 (0400569) DWR↗ (1899-06-22, 1.3 cfs decreed): last active 1990 — 34 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
HERSHMAN DITCH 2 (0400571) DWR↗ (1897-05-31, 1.0 cfs decreed): last active 1990 — 34 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
KINKAID DITCH (0400572) DWR↗ (1892-12-31, 0.8 cfs decreed): last active 1990 — 34 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1994) -- early absence of record is weak evidence of nonuse
MORAINE PARK WELL 1-4019 (0405568) DWR↗ (1959-07-01, 0.2 cfs decreed): last active 1999 — 25 years idle
JAYHAWKER PIT M-1977-427 (0405575) DWR↗ (1981-01-01, 0.0 cfs decreed): last active 1999 — 25 years idle

Compliance screens (23 advisory flags)

Screened 68 of 1296 structures with rights (115 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.

ADAMS TUNNEL (0404634) DWR↗: Observed p99 daily rate 560.0 cfs (max 842.3) exceeds total decreed absolute 116.6 cfs across 34907 recorded day(s).
HERHOLD DITCH (0400706) DWR↗: Observed p99 daily rate 212.0 cfs (max 212.0) exceeds total decreed absolute 0.2 cfs across 344 recorded day(s).
EVANSTOWN DITCH (0400517) DWR↗: Observed p99 daily rate 37.0 cfs (max 82.5) exceeds total decreed absolute 29.3 cfs across 25457 recorded day(s).
UNION DITCH (0400582) DWR↗: Observed p99 daily rate 16.4 cfs (max 33.0) exceeds total decreed absolute 12.0 cfs across 7047 recorded day(s).
RIST GOSS DITCH (0400541) DWR↗: Observed p99 daily rate 11.0 cfs (max 18.6) exceeds total decreed absolute 6.4 cfs across 9430 recorded day(s).
WELDON SPG (0401629) DWR↗: Observed p99 daily rate 10.0 cfs (max 18.0) exceeds total decreed absolute 0.1 cfs across 1142 recorded day(s).
R W WAGNER RESERVOIR (0403719) DWR↗: Observed p99 daily rate 10.0 cfs (max 12.6) exceeds total decreed absolute 7.6 cfs across 362 recorded day(s).
BLACK CANNON DITCH (0400561) DWR↗: Observed p99 daily rate 6.1 cfs (max 6.1) exceeds total decreed absolute 5.0 cfs across 790 recorded day(s).
A G PEARSON PL (0400551) DWR↗: Observed p99 daily rate 5.0 cfs (max 23.0) exceeds total decreed absolute 2.4 cfs across 9074 recorded day(s).
JIM EGLIN DITCH (0400596) DWR↗: Observed p99 daily rate 5.0 cfs (max 9.0) exceeds total decreed absolute 3.6 cfs across 12177 recorded day(s).

Seniority (top structures by decreed rate)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Decreed abs (AF)	Conditional?
HANDY DITCH (0400521) DWR↗	1861-11-10	24	2250.8	0	—
BARNES DITCH (0400501) DWR↗	1861-11-10	27	2021.2	0	—
HOME SUPPLY DITCH (0400524) DWR↗	1861-11-10	29	1305.4	0	—
BOULDER LARIMER CO IRR MFG D (0400588) DWR↗	1875-06-30	8	1136.7	0	—
LOVELAND GREELEY CANAL (0400532) DWR↗	1861-11-10	30	867.0	0	yes
LOUDEN DITCH (0400530) DWR↗	1861-11-10	31	864.6	0	—
DILLE TUNNEL (0400540) DWR↗	1861-11-10	27	791.0	0	—
GEORGE RIST DITCH (0400520) DWR↗	1861-11-10	24	586.8	0	—
OLYMPUS TUNNEL (0401000) DWR↗	1861-11-10	21	566.0	0	—
ESTES PARK FOOTHILLS PL (0400516) DWR↗	1933-09-14	1	550.0	0	—
HILLSBOROUGH DITCH (0400523) DWR↗	1861-11-10	7	284.1	0	yes
HOME SUPPLY DITCH DRY CREEK DIVERSION (0400531) DWR↗	1881-07-15	1	275.0	0	—
SOUTH SIDE DITCH (0400543) DWR↗	1861-11-10	26	246.1	0	—
LOVELAND PIPELINE (0400511) DWR↗	1861-11-10	24	159.9	223	yes
ADAMS TUNNEL (0404634) DWR↗	1965-06-24	2	116.6	0	—

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

Water-court filings this month (division-wide)

16 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 16 filings, with excerpts

Case	What it asks	County	Excerpt
`2026CW3054`	new underground right	—	CASE NUMBER 2026CW3054 BRIAN ROBERT WEISSEG LIVING TRUST DATED MAY 15, 2011, AMANDA VINTON WEISSEG LIVING TRUST DATED DECEMBER 10, 2014 , c/o Brian Robert Weisseg and Amanda Vinton Weisseg, c/o John P. Justus, CURTIS, JUSTUS, & ZAHEDI, LLC, 1333 W. 120th Ave.,…
`2026CW3062`	—	—	CASE NUMBER 2026CW3062 PRI #2, LLC (“Applicant”), 2138 Flying Horse Club Drive, Colorado Springs, Colorado 80921. Please forward all correspondence or inquiries regarding this matter to Attorneys for Applicant: Alan G. Hill; Ashley Pollock Zahedi; Nicoli R. Bo…
`2026CW3106`	—	—	CASE NUMBER 2026CW3106 STANLEY E. KELLOGG, PO Box 1935 Grand Lake, CO 80447. Direct all pleadings and correspondence to Chris D. Cummins and Sedona E. Chavez, Monson, Cummins, Shohet & Farr, LLC, 13511 Northgate Estates Dr., Ste. 250, Colorado Springs, CO 8092…
`2026CW3107`	—	—	CASE NUMBER 2026CW3107 Colorado Division of Parks and Wildlife - Order for Change of Venue to WD2.…
`2026CW3108` 0107223 0107980 0107981	reasonable diligence, make absolute	—	CASE NUMBER 2026CW3108 WEITZEL LAND LLC , 28271 Road L, Brush, Colorado 80723, Lawrence Custer Grasmick Jones & Donovan LLP Attorneys for Applicant, Weitzel Land LLC Ryan M. Donovan, #44435 Regan M. O’Donnell, #62937 APPLICATION TO MAKE CONDITIONAL WATER RIGHT…
`2026CW3109`	change of water right	—	CASE NUMBER 2026CW3109 ROBERT AND ALLISON JOHNSON, 1100 Shoreline Dr, Windsor, CO 80550, 970-581-2994. Please send all further pleadings to: Daniel K. Brown, Esq. and Whitney Phillips, Esq. Fischer, Brown, Bartlett, Larsen & Irby, P.C., 1319 E. Prospect Road, …
`2026CW3110`	reasonable diligence	—	CASE NUMBER 20 26CW3110 (Case No. 19CW3038, 09CW279) THE CITY OF AURORA , COLORADO, a municipal corporation of the Counties of Adams, Arapahoe and Douglas acting by and through its Utility Enterprise (“Aurora" or "Applicant"). APPLICATION FOR A FINDING OF REAS…
`2026CW3111`	—	IN WELD	CASE NUMBER 2026CW3111 CONCERNING THE APPLICATION FOR WATER RIGHTS OF THE COLORADO DIVISION OF PARKS AND WILDLIFE AND THE PARKS AND WILDLIFE COMMISSION, IN WELD COUNTY ; Colorado Division of Parks and Wildlife and the Parks and Wildlife Commission (“CPW”), 606…
`2026CW3112` 0904297	reasonable diligence	ASONABLE DILIGENCE IN JEFFERSON	CASE NUMBER 2026CW3112 (2019CW3233, 2013CW3067, 2002CW138) APPLICATION FOR FINDING OF REASONABLE DILIGENCE IN JEFFERSON COUNTY. RED ROCKS COUNTRY CLUB c/o Richard J. Mehren, Cameron J. Abatti, Moses, Wittemyer, Harrison and Woodruff, P.C., 2595 Canyon Boulevar…
`2026CW3113`	change of water right	ATE POINT OF DIVERSION IN WELD	CASE NUMBER 20 26CW3113 APPLICATION FOR CHANGE OF WATER RIGHT TO ADD ALTERNATE POINT OF DIVERSION IN WELD COUNTY. 1. Name and Address of Applicant . GWIP, LLC, 252 Clayton Street, Fourth Floor, Denver, Colorado 80206. Copies of all pleadings and other correspo…
`2026CW3114`	reasonable diligence	THE	CASE NUMBER 2026CW3114 CONCERNING THE APPLICATION FOR WATER RIGHTS OF THE COUNTY OF BOULDER (SUCCESSOR TO CEMEX, INC.) APPLICATION FOR FINDING OF REASONABLE DILIGENCE IN BOULDER COUNTY . Attorneys for applicant: Andrea L. Benson, Esq., Reg. No. 33176, Gilbert …
`2026CW3115`	plan for augmentation, new underground right	—	CASE NUMBER 2026CW3115 DORADO AND RAMIRO ROSALES , 14551 Imboden Rd, Hudson, CO 80642. James J Petrock, John D Buchanan, Hayes Poznanovic Korver LLC, 700 17 th Street, Suite 1800, Denver, CO 80202. APPLICATION FOR UNDERGROUND WATER RIGHTS FROM NONTRIBUTARY AND…
`2026CW3116`	new underground right	—	CASE NUMBER 2026CW3116 ROBERT D HOFFMANN AND AMY LEE HOFFMANN , 4962 N State Highway 67, Sedalia, CO, 80135. Philip E. Lopez, Eric K. Trout, Fairfield and Woods, P.C., 1801 California Street, Suite 2600, Denver, CO, 80202. APPLICATION FOR UNDERGROUND WATER RIG…
`2026CW3117`	reasonable diligence	—	CASE NUMBER 20 26CW3117 LOWER POUDRE AUGMENTATION COMPANY, THE NEW CACHE LA POUDRE IRRIGATING COMPANY, AND THE CACHE LA POUDRE RESERVOIR COMPANY, 33040 Railroad Avenue, P.O. Box 104. Lucerne, CO 80646, (970) 352-0222. Please send all further pleadings to: Bren…
`2026CW3118`	—	DOUGLAS	CASE NUMBER 2026CW3118 ROBERT H BASTIAANS AND JANICE A YUVAN, 10440 Meadow Run, Parker, CO, 80134. Philip E. Lopez, Eric K. Trout, Fairfield and Woods, P.C., 1801 California Street, Suite 2600, Denver, CO, 80202. APPLICATION FOR AMENDMENT OF A PRIOR DECREE IN …
`2026CW8`	new storage right	RIGHT IN CLEAR CREEK	CASE NUMBER 2026CW8 JONELLE AND JOHN PAUL HADDAD, P.O. Box 139, Dumont, CO 80436. 720 -951-1183. APPLICATION FOR ABSOLUTE/CONDITIONAL WATER STORAGE RIGHT IN CLEAR CREEK COUNTY. Date of original decree: 07-30-20 in case 20CW7, WD1. Haddad Pond fka Duke Pond loc…

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
BERNHARDT PIT	37-90-137(11) GRAVEL PIT PLAN	Approved	2026-12-31	0403007	plan file
KAUFFMAN NO.1 PIT	37-90-137(11) GRAVEL PIT PLAN	Approved	2026-12-31	0402530	plan file
TWO RIVERS P124 PIT	37-90-137(11) GRAVEL PIT PLAN	Approved	2026-12-31	—	plan file
WAGNER KAUFFMAN #3 PIT	37-90-137(11) GRAVEL PIT PLAN	Approved	2026-12-31	0402529	plan file
LARIMER PIT	37-90-137(11) GRAVEL PIT PLAN	Approved	2027-07-31	0402525	plan file
MILLIKEN TOWN OF	37-92-308(4) PLAN PENDING COURT APPLICATION	Approved	—	—	plan file
BURNCO COLORADO LLC - MILLIKEN RMX BATCH PLANT AND TLT WELL NO. 1	37-92-308(4) PLAN PENDING COURT APPLICATION	Pending	—	—	plan file
TOWN OF JOHNSTOWN - HOME SUPPLY	37-92-308(5) PLANS LESS THAN 5 YEARS	Pending	—	—	plan file
AMEN AGGREGATE RESOURCE	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	—	plan file
BONSER PIT	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	—	plan file
BROWNWOOD PIT	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	0402546	plan file
CHALLENGER PIT	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	—	plan file
GARDELS PIT	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	—	plan file
KIRTRIGHT PIT	37-90-137(11) GRAVEL PIT PLAN	Division Review	—	—	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	WIND RIVER NEAR ESTES PARK (WINDESCO)	14.5	0.5	502.1	+501.6	0.0	Unaccounted +501.6 cfs gain over 0.0 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	BIG THOMPSON RIVER ABOVE LAKE ESTES (BTABESCO)	19.0	502.1	51.1	-451.0	4.5	Unaccounted -451.0 cfs loss over 4.5 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	NORTH FORK BIG THOMPSON RIVER AT DRAKE, CO. (BTNFDRCO)	32.4	390.1	19.3	-370.9	11.2	Unaccounted -370.9 cfs loss over 11.2 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	OLYMPUS TUNNEL (ESTES FOOTHILLS CANAL) (OLYTUNCO)	21.2	139.9	390.1	+250.2	0.6	Unaccounted +250.2 cfs gain over 0.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	BIG THOMPSON RIVER BELOW LAKE ESTES (BTBLESCO)	20.6	51.1	139.9	+88.8	1.6	Unaccounted +88.8 cfs gain over 1.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	CHARLES HANSEN FEEDER CANAL BELOW BIG THOMPSON SIPHON (HFCBBSCO)	40.9	17.1	85.7	+68.6	1.3	Unaccounted +68.6 cfs gain over 1.3 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	USBR POWER PLANT AT BIG THOMPSON CANYON MOUTH (BTPPMCCO)	41.2	58.5	4.7	-53.9	0.1	Unaccounted -53.9 cfs loss over 0.1 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	BIG THOMPSON RIVER BELOW HILLSBOROUGH DIVERSION (BIGHILCO)	56.5	69.5	21.4	-48.1	3.4	Unaccounted -48.1 cfs loss over 3.4 mi. Returns in this reach with stale data (BTM DITCH BROWNWOOD RETURN) — over-reporting elsewhere is also possible.
MAINSTEM	BIG THOMPSON RIVER AT LOVELAND, CO. (BIGLOVCO)	53.1	30.0	69.5	+39.5	3.5	Unaccounted +39.5 cfs gain over 3.5 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	GREELEY LOVELAND DIVERSION AT LOVELAND (GRELOVCO)	49.6	0.0	30.0	+30.0	2.7	Unaccounted +30.0 cfs gain over 2.7 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	CHARLES HANSEN FEEDER CANAL WASTEWAY TO BIG THOMPSON (HFCWASCO)	41.1	85.7	58.5	-27.2	0.2	Unaccounted -27.2 cfs loss over 0.2 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	BUCKHORN CREEK NEAR MASONVILLE, CO (BUCRMVCO)	44.5	24.6	3.5	-21.1	2.7	Unaccounted -21.1 cfs loss over 2.7 mi. Returns in this reach with stale data (HANDY DITCH SYLVAN DALE RANCH RETURN) — over-reporting elsewhere is also possible.
MAINSTEM	HANSEN FEEDER CANAL LOVELAND TURNOUT (HFCLOVCO)	41.8	4.7	24.6	+19.9	0.6	Unaccounted +19.9 cfs gain over 0.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	WIND RIVER NEAR ESTES PARK (WINDESCO)	14.5	18.0	0.5	-17.5	1.0	Unaccounted -17.5 cfs loss over 1.0 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.

Gage ⇅	Station ⇅	Avg cfs Aug 17–Aug 23 ⇅	% Hist Median ⇅	Rank ⇅	Δ1wk ⇅	Δ4wk ⇅	Yrs ⇅	Status ⇅
BTPPMCCO	USBR POWER PLANT AT BIG THOMPSON CANYON MOUTH	4.7	4%	0	-78	-88	28.2	SHORT_RECORD
BTBMORCO	BIG THOMPSON BL MORAINE PARK NR ESTES PARK, CO	18.0	52%	0	-1	-29	27.3	SHORT_RECORD
BOULARCO	BOULDER-LARIMER DITCH NEAR BERTHOUD	0.0	0%	0	+0	+0	23.1	SHORT_RECORD
GRELOVCO	GREELEY LOVELAND DIVERSION AT LOVELAND	30.0	60%	28	-1	-12	21.0	SHORT_RECORD
BIGHILCO	BIG THOMPSON RIVER BELOW HILLSBOROUGH DIVERSION	21.4	79%	34	-18	-14	28.4	SHORT_RECORD
HFCLOVCO	HANSEN FEEDER CANAL LOVELAND TURNOUT	24.6	122%	64	-3	-4	24.2	SHORT_RECORD
BTABESCO	BIG THOMPSON RIVER ABOVE LAKE ESTES	51.1	52%	0	-6	-68	90.4	OK
BIGLASCO	BIG THOMPSON RIVER AT MOUTH NEAR LA SALLE	26.2	48%	27	-20	+7	124.2	OK
BTNFDRCO	NORTH FORK BIG THOMPSON RIVER AT DRAKE, CO.	19.3	76%	28	-4	-12	55.9	OK
LTCANYCO	LITTLE THOMPSON RIVER AT CANYON MOUTH NEAR BERTHOUD	0.5	53%	29	-0	-0	33.3	OK
WINDESCO	WIND RIVER NEAR ESTES PARK	0.5	84%	46	-0	-1	57.2	OK
BUCRMVCO	BUCKHORN CREEK NEAR MASONVILLE, CO	3.5	98%	49	-2	+3	64.6	OK
DILTUNCO	DILLE TUNNEL NEAR DRAKE	17.1	117%	52	+12	-25	85.3	OK
OLYTUNCO	OLYMPUS TUNNEL (ESTES FOOTHILLS CANAL)	390.1	104%	53	-118	-128	70.7	OK
HFCBBSCO	CHARLES HANSEN FEEDER CANAL BELOW BIG THOMPSON SIPHON	85.7	134%	58	-9	-20	84.9	OK
BIGLOVCO	BIG THOMPSON RIVER AT LOVELAND, CO.	69.5	120%	72	-19	-8	47.5	OK
HFCWASCO	CHARLES HANSEN FEEDER CANAL WASTEWAY TO BIG THOMPSON	58.5	463%	77	+59	+41	70.3	OK
BTBLESCO	BIG THOMPSON RIVER BELOW LAKE ESTES	139.9	143%	84	+84	+34	116.5	OK
ADATUNCO	ALVA B. ADAMS TUNNEL AT EAST PORTAL NEAR ESTES PARK	502.1	145%	94	-15	-3	90.0	OK