Boulder Creek

Division 1 · Water District 6 · As of 2026-08-31 00:36 MDT

Full analysis

Boulder Creek on the ground — the ditches, wells, reservoirs and gages of Water District 6 · clicktap anything for its record

Snowpack — no snow on the ground at 3 SNOTEL sites — normal for the date; the snow year begins in October and typically peaks around April 9. Runoff outlook — Boulder Ck nr Orodell: even odds of at least 28 kAF over 06-01 to 09-30 — 62% of a normal season, per NRCS, issued 2026-06-01 — the season’s final; new forecasts begin in January. Runoff outlook — South Boulder Ck nr Eldorado Springs: even odds of at least 15 kAF over 06-01 to 09-30 — 56% 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)	% of median	Typical peak
Lake Eldora	9700	0.0	—	April 9 (14.0 in)
Niwot	9940	0.0	—	April 19 (15.0 in)
University Camp	10330	0.2	—	May 7 (19.9 in)

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

90%	70%	50%	30%	10%	Normal
23	26	28	30	34	45

South Boulder Ck nr Eldorado Springs — 06-01 to 09-30 volume, thousand acre-feet (chance the volume is AT LEAST this):

90%	70%	50%	30%	10%	Normal
9	12	15	16	19	27

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: 0 parent disagreements, 6 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 9 streams, 9 agree. Know this water? Tell us →

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

Fourmile Creek (15 mi) · Bear Canyon Creek (8 mi) · Dry Creek (6 mi) · Bummers Gulch (4 mi) · Johnson Gulch (3 mi) · Bullhead Gulch (3 mi)

Reconstruct conditions as of

Evolution of the network

This year, in context

In the weeks around 2026-08-26 (the newest reading on file), flows at the 17 ranked gages are running at a median 19% of their own long-term norm for this window — 13 below a typical year, 4 at or above. Driest relative to its record: GREEN DITCH RETURN TO BOULDER CREEK, ranking 1st lowest of 5 years.

How this comparison is made

Each gage's mean flow over the 3 days either side of 2026-08-26, 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 2026-08-31 00:46 from 104 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 104 gages with enough record, 6 are trending down and 1 up, and 7 carry a detected shift. The clearest is South Boulder Creek near Eldorado Springs, its annual mean flow changing -2.67 cfs per decade (-4.4% of its median annual flow) over 124 years (p<0.0001). The other 96 show no clear signal either way.

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

Gage	Trend	Change / decade cfs · % of median annual flow	Significance	Years	Changepoint
▸ South Boulder Creek near Eldorado Springs BOCELSCO	↓ decreasing	-2.67 cfs -4.4%	p<0.001	124	~1952
▸ Boulder Creek near Orodell BOCOROCO	↓ decreasing	-2.77 cfs -3.5%	p<0.001	116	~1962
▸ South Boulder Creek below Gross Reservoir BOCBGRCO	↓ decreasing	-7.04 cfs -5.1%	p<0.001	58	~1991
▸ South Boulder Creek Diversion near Eldorado Springs BOSDELCO	↓ decreasing	-4.09 cfs -5.0%	p=0.003	59	~1991
▸ Boulder Creek at Mouth near Longmont BOCLONCO	↑ increasing	+4.24 cfs +6.5%	p=0.005	69	~1954
▸ Fourmile Creek at Orodell FOUOROCO	↓ decreasing	-0.78 cfs -12.9%	p=0.027	16	—
▸ Boulder Creek at North 75th St. near Boulder BOCNORCO	↓ decreasing	-6.80 cfs -7.9%	p=0.037	39	~2001
▸ ⚠️ North Boulder Creek at Silver Lake NOBOSICO	no clear trend	+8.88 cfs +30.0%	p=0.189	14	~1919

⚠️ 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.

96 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. 91 gage(s) and 86 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1950. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Decade	Gages with data (median yr)	Structures reporting (median yr)
1890s	1	0
1900s	2	0
1910s	4	0
1920s	4	0
1930s	5	0
1940s	5	0
1950s	6	60
1960s	7	56
1970s	11	58
1980s	13	64
1990s	12	78
2000s	13	84
2010s	18	90
2020s	80	77

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 34% of 225 schematic-relevant structures. Kink count trend: increasing (p=0.002), kink magnitude trend: no_trend (p=0.917) across 9 qualifying year(s).

Reach gain/loss shifts (1950–2026)

Mass-balance kinks computed for every summer month back to 1950 (2413 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.

SOUTH BOULDER CREEK DIVERSION NEAR ELDORADO SPRINGS: reach shifted from -122 cfs to +19 cfs summer mean (more gaining, p=0.000, 62 yr) [crystalline foothills: 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=0.5) -- part of it may be unaccounted water becoming accounted, not hydrologic change]

Groundwater now has its own tab: 536 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 64 reservoir(s), end-of-year storage back to 1950, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 111-year window with full coverage (1916–2026), the dominant shared pattern across 3 gage(s) explains 77% of year-to-year variance (almost certainly a basin-wide climate/snowpack driver).

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

Structures most implicated by reconciliation (as of 2026-08-05)

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.

DAVIS RES 1&2 (diversion): +89.4 cfs (100% of that reach's correction)
LAFAYETTE BLDR C ALT PT (diversion): -86.2 cfs (100% of that reach's correction)
BULL HEAD GULCH P L (diversion): -34.4 cfs (50% of that reach's correction)
GOOSE HAVEN POND 2 (diversion): -34.4 cfs (50% of that reach's correction)
S BOULDER DIVR CONDUIT (diversion): -24.7 cfs (100% of that reach's correction)
WELLMAN DITCH (diversion): +22.1 cfs (100% of that reach's correction)
LAFAYETTE PIPELINE RETURN TO SOUTH BOULDER CREEK (return): -19.7 cfs (100% of that reach's correction)
HARTMAN RES (diversion): +19.2 cfs (25% of that reach's correction)
LAFAYETTE BOULDER C PL 1 (diversion): +19.2 cfs (25% of that reach's correction)
KUGELER PIPELINE 1 (diversion): +19.2 cfs (25% of that reach's correction)

Data provenance & quality

Where these numbers come from and how far they can be trusted. Grade B (4/6 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	current	newest gage reading is 5 day(s) old
diversion record	expected-lag	newest diversion record is -61 day(s) old (DWR publishes ~1 year in arrears)
structure coverage	sparse	34% of schematic structures have data

Independent check: PASS — 100.0000% agreement across 304,701 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: WARN — 94.80% day-level agreement with USGS's own published records for the same gages, across 14 co-listed station(s) and 147,201 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.

104 gage(s) / 489,787 daily values (1896-01-01–2026-08-26); 212 structure(s) with diversion records; 1867 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.

1,543 water-level measurements across 536 monitored well(s) — 242 alluvial, 80 bedrock — plus 2 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 2 well(s) with enough record for a trend test: 1 declining, 1 rising.

Fastest-declining wells	Setting	ft / decade	Span	p
▸ SC00106931CBD	unknown	-26.2	11 yr	0.0007

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.

SOUTH BOULDER CREEK DIVERSION NEAR ELDORADO SPRINGS: 2 alluvial well(s) nearby

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.

64 reservoir(s) with 30,185 storage measurement(s), 1950–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 49,477 AF across 25 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)
▸ GROSS RES (0604199)	23,325	2024-10-31	—	—	dossier →
▸ BECKY RES NO 1 (0604272)	11,468	1980-06-30	—	—	dossier →
▸ 0604515	8,816	2012-10-31	—	—	dossier →
▸ BARKER MEADOW RES (0604172)	7,895	2024-10-31	—	—	dossier →
▸ VALMONT LAKE RES (0604230)	7,150	2013-10-31	—	—	dossier →
▸ MARSHALL LAKE (0604212)	5,126	2024-10-31	—	—	dossier →
▸ BASELINE RES (0604173)	4,116	2023-10-31	—	—	dossier →
▸ PANAMA RES 1 (0604185)	3,279	2020-09-30	—	—	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)	% of median	Typical peak
Lake Eldora	9700	0.0	—	April 9 (14.0 in)
Niwot	9940	0.0	—	April 19 (15.0 in)
University Camp	10330	0.2	—	May 7 (19.9 in)

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

Two ways a snow year goes wrong (1979–2026)

A bad snow year here comes in two flavors (both called snow drought), and the river feels them differently. In 8 of the last 48 winters the snow never came — the pack peaked below 80% of its median. In 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 56% of median.

The snow never came: 1981, 1985, 1991, 2001, 2002, 2004, 2012, 2026. The snow left early: 2006.

Computed by this site from 3 SNOTEL sites’ full daily records (NRCS AWDB, back to 1979). Each year is measured against each site’s own multi-decade median — not the 1991–2020 normal the chart above uses — so the 1980s grade against a fair baseline. Peak and melt-out need 85% of the season’s days on the record; thin years are dropped, not guessed. Derived from snow measurements alone — it cannot tell dry-from-warm causes apart, only what the snowpack did.

Runoff outlook — Boulder Ck nr Orodell

NRCS's final issue (2026-06-01) calls it even odds that at least 28 kAF arrives over 06-01 to 09-30 — 62% of a normal season; almost certainly at least 23, probably not more than 34. Our own record at this gage shows 10 kAF so far this period (partial record: 73 of 93 days). New forecasts begin in January. How to read these numbers →

90% chance of at least	70% chance of at least	50% chance of at least	30% chance of at least	10% chance of at least	Normal	Observed
23	26	28	30	34	45	10*

How good are these forecasts here? (1950–2025)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 75 seasons: the median miss of the 50% forecast is 24%, with a high bias of 16%, and the observed volume landed inside the stated 10–90% band 56% of the time (a calibrated forecast would say 80%).

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

What April snow has meant for this river (1979–2026)

Across 48 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 77% of a normal season (a snow-to-runoff elasticity of 0.7). In warm, early-melt years the river delivered a median of 82% of a normal season, against 97% in typical years — the timing of the melt matters, not just its size. This year opened April at 26% of median snow and delivered 36% of a normal season.

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

Runoff outlook — South Boulder Ck nr Eldorado Springs

NRCS's final issue (2026-06-01) calls it even odds that at least 15 kAF arrives over 06-01 to 09-30 — 56% of a normal season; almost certainly at least 9, probably not more than 19. 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
9	12	15	16	19	27

Right now

This is the 2nd-driest week 32 in 129 years of record at SOUTH BOULDER CREEK NEAR ELDORADO SPRINGS, CO. (as of 2026-08-03; this week’s flow sits at the 2nd percentile for the date). On this week’s US Drought Monitor, Boulder County is 85% in D3 extreme drought (2026-08-25). The law agrees: the most senior active call leaves 100% of this district’s decreed flow rights junior to the calling right this week.

Every year since 1896, week by week

Each thin row is a year at SOUTH BOULDER CREEK NEAR ELDORADO SPRINGS, 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 Boulder, Gilpin, Jefferson, Weld 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 2004 — 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 (2215 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.

1571–1999: this river before anyone measured it

Tree rings record wet and dry years centuries before the first gage. This is the published reconstruction of annual flow at Boulder Creek at Orodell — 429 years, with its uncertainty band drawn, not implied. A reconstruction is an estimate, not a measurement: it answers “is this decade unusual in four centuries?”, and nothing in this site’s statistics uses it.

Woodhouse, C.A. and J.J. Lukas (2006), Multi-century tree-ring reconstructions of Colorado streamflow for water resource planning, Climatic Change 78; data via NOAA NCEI World Data Service for Paleoclimatology / TreeFlow. Source data ↗

This basin’s droughts, by its own record

Drought	Span	Weeks	Trough percentile	Recovery
unnamed dry spell	2024-12-02 → 2025-04-21	20	26th (2024-12-30)	42 weeks
the 2020-22 drought	2023-03-06 → 2023-11-06	35	17th (2023-06-05)	21 weeks
the 2020-22 drought	2020-08-24 → 2022-10-24	113	15th (2021-12-20)	75 weeks
the 2018 drought	2018-07-16 → 2019-04-08	38	17th (2018-10-15)	260 weeks
the 2012-13 drought	2012-08-27 → 2013-08-05	49	20th (2012-10-08)	8 weeks
the 2002 drought	2002-06-10 → 2003-02-17	36	9th (2002-09-02)	8 weeks
the 2002 drought	2000-11-27 → 2001-10-22	47	15th (2001-04-23)	11 weeks
unnamed dry spell	1994-10-24 → 1995-08-21	43	21st (1994-11-28)	0 weeks
unnamed dry spell	1989-10-16 → 1990-04-23	27	20th (1989-12-25)	0 weeks
unnamed dry spell	1988-10-31 → 1989-05-01	26	22nd (1988-12-12)	51 weeks
the 1981 drought	1981-03-23 → 1982-03-15	51	17th (1981-08-03)	18 weeks
unnamed dry spell	1966-07-04 → 1967-04-10	40	18th (1966-08-29)	29 weeks
the 1963-64 drought	1964-06-22 → 1965-08-16	60	16th (1965-02-22)	0 weeks
the 1963-64 drought	1963-06-03 → 1963-11-11	23	13th (1963-07-29)	6 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 1991, federal crop insurance has paid $38,555,719 in drought-caused claims across Boulder, Gilpin, Jefferson, Weld counties — 16.7% of all insured crop losses there. The worst year was 2022 ($8,809,218).

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

When this basin claimed its water

Every bar is a year’s new appropriations (2,104 rights across 129 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is +0.01 — 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 1859-10-01 to 2022-04-06. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 100% of a median irrigation season and 48% in a dry one. 25 abandonment screens and 30 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: 2727 across 1867 structure(s); 201 structure(s) carry 895 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	169	1875-06-30
2017	355	246	1881-02-01
2018	365	266	1876-05-10
2019	365	266	1881-02-01
2020	366	213	1869-04-01
2021	349	235	1867-04-15
2022	365	306	1867-04-15
2023	347	282	1869-06-01
2024	366	250	1881-02-01
2025	365	385	1875-03-10

What the water is for — decade by decade

Of the water this district's structures diverted, the share whose decree includes municipal supply moved from 67% in the 1950s to 77% in the 2020s.

The decades, and how the attribution works

Every structure's recorded diversions, attributed to what its water was decreed FOR in that year. Colorado decrees are usually multi-use (“IRR MUN COM IND…”), so these are shares of water whose decree includes a use — non-exclusive, and they do not sum to 100%. A right that adds municipal use in 1988 counts toward it only after. Decades before this basin's modern reporting era are flagged: their records are thinner, not their rivers drier. Shares of recorded diverted volume, not of water rights or of acreage. A structure's water is attributed only to uses decreed by that year, so a later municipal decree cannot reach back and recolour earlier diversions. Families overlap -- a ditch decreed for irrigation and municipal supply counts in both -- so shares can sum past 100%. Volume the record cannot attribute is reported separately, never distributed.

Decade	Recorded AF	Structures	Includes municipal	Unattributed
1950s	2,191,222	65	67%	54%
1960s	2,120,777	64	66%	52%
1970s	1,862,179	93	78%	11%
1980s	2,351,193	100	82%	6%
1990s	2,744,926	84	82%	2%
2000s	2,858,143	111	83%	2%
2010s	3,389,624	125	71%	13%
2020s	1,516,672	113	77%	17%

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

BOULDER LEFT HAND DITCH (0600513) DWR↗ stopped 2025-09-25 (36+ days) — call at CLEAR CR PLATTE RIVER D curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
LEGGETT DITCH (0600537) DWR↗ stopped 2025-09-17 (44+ days) — call at CLEAR CR PLATTE RIVER D curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
FARMERS DITCH (0600525) DWR↗ stopped 2025-09-08 (18+ days) — call at JONES DONNELLY DITCH curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
MCCARTY DITCH (0600542) DWR↗ stopped 2025-08-27 (8+ days) — call at JONES DONNELLY DITCH curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
SMITH EMMONS DITCH (0600553) DWR↗ stopped 2025-08-18 (6+ days) — call at RURAL DITCH curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
HIGHLAND SOUTH SIDE DITCH (0600532) DWR↗ stopped 2025-08-15 (9+ days) — call at JONES DONNELLY DITCH curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
LEYNER COTTONWOOD DITCH (0600565) DWR↗ stopped 2025-08-15 (25+ days) — call at JONES DONNELLY DITCH curtailing 100% of its decreed rate [heuristic-partial, district-confirmed]
DRY CREEK DAVIDSON DITCH (0600569) DWR↗ stopped 2025-07-29 (19+ days) — call at JONES DONNELLY DITCH curtailing 100% of its decreed rate [heuristic-strong, district-confirmed]
MCCARTY DITCH (0600542) DWR↗ stopped 2025-07-17 (6+ days) — call at WARD DITCH curtailing 100% of its decreed rate [heuristic-strong]
LEYNER COTTONWOOD DITCH (0600565) DWR↗ stopped 2025-07-13 (14+ days) — call at EAST BOULDER DITCH curtailing 100% of its decreed rate [heuristic-partial, district-confirmed]
COMMUNITY DITCH (0600564) DWR↗ stopped 2025-05-15 (13+ days) — call at EAST BOULDER DITCH curtailing 99% of its decreed rate [heuristic-partial, district-confirmed]
COMMUNITY DITCH (0600564) DWR↗ stopped 2025-04-25 (5+ days) — call at BIJOU CANAL curtailing 87% of its decreed rate [heuristic-partial, district-confirmed]

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
LEGGETT-VALMONT INLET D (0600893) DWR↗	1864-05-01	100.0% / 42.1%	5.6% / 0.0%
KINNEAR DITCH (0600913) DWR↗	1872-05-20	61.2% / 17.3%	10.7% / 0.0%
COMMUNITY DITCH (0600564) DWR↗	1859-10-01	100.0% / 100.0%	5.6% / 0.0%
BOULDER WHITE ROCK DITCH (0600516) DWR↗	1862-06-01	100.0% / 44.4%	8.7% / 0.0%
KINNEAR DITCH NO 2 (0600614) DWR↗	1872-05-20	61.2% / 17.3%	14.8% / 0.0%
NEW DRY CR CARRIER DITCH (0600902) DWR↗	1859-10-01	100.0% / 100.0%	5.6% / 0.0%
S BOULDER DIVR CONDUIT (0600590) DWR↗	1930-01-01	10.7% / 0.0%	10.7% / 0.0%
0600502 DWR↗	1922-11-10	6.1% / 0.0%	6.1% / 0.0%
EAST BOULDER DITCH (0600575) DWR↗	1860-05-01	100.0% / 92.1%	10.7% / 0.0%
LOWER BOULDER DITCH (0600538) DWR↗	1859-10-01	100.0% / 100.0%	5.6% / 0.0%
DENVER POWER CONDUIT 1 (0600568) DWR↗	1945-05-10	8.7% / 0.0%	8.7% / 0.0%
GOODHUE DITCH (0600650) DWR↗	1859-10-01	100.0% / 100.0%	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 ~1950 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

WELLMAN DITCH (0600557) DWR↗ (1917-03-08, 120.0 cfs decreed): last active 1953 — 72 years idle
0600530 DWR↗ (1862-06-01, 1.8 cfs decreed): last active 1974 — 51 years idle
0604244 DWR↗ (1872-04-01, 0.0 cfs decreed): last active 1979 — 46 years idle
0604245 DWR↗ (1876-04-01, 0.0 cfs decreed): last active 1979 — 46 years idle
MARFELL LAKE NO 1 (0604210) DWR↗ (1880-04-01, 0.0 cfs decreed): last active 1980 — 45 years idle
MARFELL LAKE NO 2 (0604211) DWR↗ (1884-04-01, 0.0 cfs decreed): last active 1980 — 45 years idle
BECKY RES NO 1 (0604272) DWR↗ (1963-01-22, 0.0 cfs decreed): last active 1980 — 45 years idle
GREEN LAKE RES NO 2 (0604253) DWR↗ (1906-10-02, 0.0 cfs decreed): last active 1985 — 40 years idle
KINNEAR DITCH NO 2 (0600614) DWR↗ (1872-05-20, 781.0 cfs decreed): last active 1989 — 36 years idle
0604249 DWR↗ (1896-02-15, 0.0 cfs decreed): last active 1989 — 36 years idle

Compliance screens (30 advisory flags)

Screened 84 of 1867 structures with rights (157 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.

BARKER MEADOW RES (0604172) DWR↗: Observed p99 daily rate 233.0 cfs (max 709.0) exceeds total decreed absolute 0.2 cfs across 18966 recorded day(s).
MARSHALL LAKE (0604212) DWR↗: Observed p99 daily rate 101.8 cfs (max 210.0) exceeds total decreed absolute 2.1 cfs across 14498 recorded day(s).
BOULDER CR MIN FLOW C (0602100) DWR↗: Observed p99 daily rate 28.1 cfs (max 612.0) exceeds total decreed absolute 16.0 cfs across 33719 recorded day(s).
DRY CREEK NO 2 DITCH (0600570) DWR↗: Observed p99 daily rate 22.0 cfs (max 35.0) exceeds total decreed absolute 19.5 cfs across 13920 recorded day(s).
DRY CREEK DAVIDSON DITCH (0600569) DWR↗: Observed p99 daily rate 17.0 cfs (max 25.7) exceeds total decreed absolute 16.7 cfs across 13304 recorded day(s).
HOWARD DITCH (0600580) DWR↗: Observed p99 daily rate 17.0 cfs (max 32.0) exceeds total decreed absolute 12.1 cfs across 38102 recorded day(s).
MCGINN DITCH (0600586) DWR↗: Observed p99 daily rate 17.0 cfs (max 30.0) exceeds total decreed absolute 10.9 cfs across 24697 recorded day(s).
GOOSE HAVEN RESERVOIR COMPLEX (0603998) DWR↗: Observed p99 daily rate 16.6 cfs (max 46.0) exceeds total decreed absolute 1.7 cfs across 12516 recorded day(s).
BULL HEAD GULCH IRR SYS (0600584) DWR↗: Observed p99 daily rate 16.3 cfs (max 17.1) exceeds total decreed absolute 4.3 cfs across 206 recorded day(s).
JONES DONNELLY DITCH (0600582) DWR↗: Observed p99 daily rate 10.0 cfs (max 27.0) exceeds total decreed absolute 9.1 cfs across 24780 recorded day(s).

Seniority (top structures by decreed rate)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Conditional?
LEGGETT-VALMONT INLET D (0600893) DWR↗	1864-05-01	9	2000.0	—
KINNEAR DITCH (0600913) DWR↗	1872-05-20	4	1644.9	—
COMMUNITY DITCH (0600564) DWR↗	1859-10-01	46	1291.8	yes
BOULDER WHITE ROCK DITCH (0600516) DWR↗	1862-06-01	9	909.1	—
KINNEAR DITCH NO 2 (0600614) DWR↗	1872-05-20	4	781.0	—
NEW DRY CR CARRIER DITCH (0600902) DWR↗	1859-10-01	24	680.0	—
S BOULDER DIVR CONDUIT (0600590) DWR↗	1930-01-01	1	461.0	yes
0600502 DWR↗	1922-11-10	1	430.0	—
EAST BOULDER DITCH (0600575) DWR↗	1860-05-01	13	405.0	—
LOWER BOULDER DITCH (0600538) DWR↗	1859-10-01	26	351.4	yes
DENVER POWER CONDUIT 1 (0600568) DWR↗	1945-05-10	1	344.0	yes
GOODHUE DITCH (0600650) DWR↗	1859-10-01	36	321.3	—
SOUTH BOULDER CANON DITCH (0600593) DWR↗	1859-10-01	22	258.4	—
DAVIDSON DITCH (0600567) DWR↗	1859-10-01	23	223.2	—
LAST CHANCE DITCH (0600615) DWR↗	1862-05-01	13	217.1	—

Recent inventory & legal-document changes

2026-08-29 — call set: LOWER LATHAM DITCH (39382)
2026-08-29 — call set: OGILVY DITCH (39386)
2026-08-29 — call set: LOWLINE DITCH (39383)
2026-08-29 — call released: 39379
2026-08-29 — call released: 39359
2026-08-28 — call set: COFFIN DAVIS DITCH (39369)
2026-08-28 — call set: PIONEER UNION DITCH (39366)
2026-08-28 — call set: WESTERN MUTUAL DITCH (39374)

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
FIRESTONE, TOWN OF	37-92-308(4) PLAN PENDING COURT APPLICATION	Approved	2026-03-31	—	plan file
CITY OF LOUISVILLE MUNICIPAL EFFLUENT	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2026-04-30	—	plan file
GOOSE HAVEN RES #2	37-90-137(11) GRAVEL PIT PLAN	Approved	2026-07-31	0602537	plan file
JASPER RESERVOIR ISF LOAN	37-83-105(2)(a) Instream Flow Loan	Approved	2026-10-31	0602556	plan file
CITY OF BOULDER BRENTON BUILDING	37-92-308(5) PLANS LESS THAN 5 YEARS	Approved	2026-11-30	0602553	plan file
CITY OF LOUISVILLE 26CW3020	37-92-308(4) PLAN PENDING COURT APPLICATION	Approved	2027-05-31	—	plan file
TURNPIKE MINING RESOURCE	37-90-137(11) GRAVEL PIT PLAN	Approved	—	—	plan file
THREE LEAF FARM	37-92-308(4) PLAN PENDING COURT APPLICATION	Decreed	2026-03-31	—	plan file
TOWN OF FREDERICK	37-92-308(4) PLAN PENDING COURT APPLICATION	Decreed	—	—	plan file
ELDORADO ARTESIAN SPRINGS LBDC SHARES	37-92-308(4) PLAN PENDING COURT APPLICATION	Pending	—	0602509	plan file
FARFRUMWURKIN, LLLP-FILE PIT 112	37-90-137(11) GRAVEL PIT PLAN	Pending	—	—	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	LOWER BOULDER DITCH (LWBDITCO)	19.9	0.0	29.3	+29.3	1.5	Unaccounted +29.3 cfs gain over 1.5 mi. Diversions in this reach with stale data (HARTMAN RES, LAFAYETTE BOULDER C PL 1, KUGELER PIPELINE 1) — under-reporting could mask an offsetting loss.
MAINSTEM	BOULDER & WELD COUNTY DITCH (BWCDITCO)	21.4	29.3	0.0	-29.3	1.4	Unaccounted -29.3 cfs loss over 1.4 mi. Likely cause: stale/missing diversion data at BULL HEAD GULCH P L, GOOSE HAVEN POND 2.
MAINSTEM	BOULDER CREEK SUPPLY CANAL TO BOULDER CREEK ABOVE ERIE TURNOUT (BCSCBCCO)	16.2	0.0	29.1	+29.1	0.4	Unaccounted +29.1 cfs gain over 0.4 mi. Diversions in this reach with stale data (DAVIS RES 1&2) — under-reporting could mask an offsetting loss.
MAINSTEM	BOULDER CREEK AT NORTH 75TH ST. NEAR BOULDER, CO (BOCNORCO)	16.6	36.7	15.8	-20.9	0.0	Unaccounted -20.9 cfs loss over 0.0 mi. Likely cause: stale/missing diversion data at LAFAYETTE BLDR C ALT PT.
MAINSTEM	SIX MILE RESERVOIR OUTLET (SIXOUTCO)	15.6	0.0	16.4	+16.4	0.1	Unaccounted +16.4 cfs gain over 0.1 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	BOULDER AND WHITEROCK DITCH TURNOUT #1 (BWRTO1CO)	15.8	16.4	0.0	-16.4	0.2	Unaccounted -16.4 cfs loss over 0.2 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	BOULDER CREEK BELOW WELLMAN DITCH (BOCWLMCO)	10.5	15.4	0.0	-15.4	0.0	Unaccounted -15.4 cfs loss over 0.0 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	BOULDER CREEK BELOW WELLMAN DITCH (BOCWLMCO)	10.4	0.9	15.4	+14.5	0.6	Unaccounted +14.5 cfs gain over 0.6 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	NORTH BOULDER FARMERS DITCH RETURN TO BOULDER CREEK (NBFRTNCO)	9.3	0.0	12.7	+12.7	0.0	Unaccounted +12.7 cfs gain over 0.0 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
MAINSTEM	NORTH BOULDER FARMERS DITCH RETURN TO BOULDER CREEK (NBFRTNCO)	9.3	12.7	1.5	-11.2	0.0	Unaccounted -11.2 cfs loss over 0.0 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
SOUTH BOULDER CREEK	SOUTH BOULDER CREEK DIVERSION NEAR ELDORADO SPRINGS (BOSDELCO)	6.5	10.1	0.0	-10.1	3.7	Unaccounted -10.1 cfs loss over 3.7 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	RURAL DITCH (RURDITCO)	28.8	0.0	10.0	+10.0	0.2	Unaccounted +10.0 cfs gain over 0.2 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
SOUTH BOULDER CREEK	MOFFAT WATER TUNNEL AT EAST PORTAL, CO. (MOFTUNCO)	-17.3	18.0	8.3	-9.7	0.0	Unaccounted -9.7 cfs loss over 0.0 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
MAINSTEM	ANDERSON DITCH (ANDDITCO)	7.9	12.6	3.4	-9.2	2.9	Unaccounted -9.2 cfs loss over 2.9 mi. No structure clearly responsible — possible ungaged diversion, channel seepage / phreatophyte loss, or evapotranspiration.
SOUTH BOULDER CREEK	SOUTH BOULDER CREEK NEAR ELDORADO SPRINGS, CO. (BOCELSCO)	6.9	0.0	9.1	+9.1	0.3	Unaccounted +9.1 cfs gain over 0.3 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
SOUTH BOULDER CREEK	SOUTH BOULDER CREEK ABOVE GROSS RESERVOIR AT PINECLIFFE (BOCPINCO)	-3.4	8.3	16.9	+8.6	13.9	Unaccounted +8.6 cfs gain over 13.9 mi. Diversions in this reach with stale data (KETTLE POND, ESPY ICE CO D NO 1, LAKE PACTOLUS DIVERSION SYSTEM) — under-reporting could mask an offsetting loss.
SOUTH BOULDER CREEK	LOUISVILLE PIPELINE (LUVPPLCO)	9.1	9.1	0.9	-8.1	2.3	Unaccounted -8.1 cfs loss over 2.3 mi. Returns in this reach with stale data (LAFAYETTE PIPELINE RETURN TO SOUTH BOULDER CREEK) — over-reporting elsewhere is also possible.
MAINSTEM	BOULDER CREEK AT NORTH 75TH ST. NEAR BOULDER, CO (BOCNORCO)	16.5	29.1	36.7	+7.5	0.3	Unaccounted +7.5 cfs gain over 0.3 mi. No structure clearly responsible — possible ungaged return flow, baseflow from groundwater, or unmodeled tributary inflow.
SOUTH BOULDER CREEK	SOUTH BOULDER CREEK BELOW GROSS RESERVOIR (BOCBGRCO)	2.9	16.9	10.1	-6.8	6.3	Unaccounted -6.8 cfs loss over 6.3 mi. Likely cause: stale/missing diversion data at GROSS RES, DENVER POWER CONDUIT 1.
MAINSTEM	PANAMA RESERVOIR OUTLET (PNMOUTCO)	24.4	6.2	0.2	-6.1	0.2	Unaccounted -6.1 cfs loss over 0.2 mi. Likely cause: stale/missing diversion data at WITTEMYER POND NO 2.
NORTH BOULDER CREEK	SILVER LAKE OUTLET (SILOUTCO)	-10.8	14.9	8.9	-6.0	6.2	Unaccounted -6.0 cfs loss over 6.2 mi. Likely cause: stale/missing diversion data at GREEN LAKE RES NO 4, GREEN LAKE RES NO 3, GREEN LAKE RES NO 2.
MAINSTEM	BOULDER CREEK AT 109 ST NEAR ERIE, CO (BOC109CO)	22.1	0.0	6.0	+6.0	0.7	Unaccounted +6.0 cfs gain over 0.7 mi. Diversions in this reach with stale data (BLOUGH'S POND) — under-reporting could mask an offsetting loss.
MAINSTEM	PANAMA RESERVOIR INLET (PNMAINCO)	23.3	6.0	0.1	-5.9	1.2	Unaccounted -5.9 cfs loss over 1.2 mi. Likely cause: stale/missing diversion data at YOUNG DITCH, NIELSEN PONDS NO 1, NIELSEN PONDS NO 2.

Gage ⇅	Station ⇅	Avg cfs Aug 24–Aug 30 ⇅	% Hist Median ⇅	Rank ⇅	Δ1wk ⇅	Δ4wk ⇅	Yrs ⇅	Status ⇅
SBBDITCO	SOUTH BOULDER & BEAR CREEK DITCH	0.0	0%	0	+0	+0	0.0	NO_DATA
COCREPCO	COAL CREEK NEAR PLAINVIEW, CO.	0.0	18%	13	+0	+0	59.1	STALE
FOUOROCO	FOURMILE CREEK AT ORODELL, CO	0.1	9%	0	-0	-0	26.0	SHORT_RECORD
BOCPINCO	SOUTH BOULDER CREEK ABOVE GROSS RESERVOIR AT PINECLIFFE	16.9	23%	0	-3	-22	18.3	SHORT_RECORD
DRYCARCO	DRY CREEK CARRIER	0.0	0%	0	+0	+0	17.5	SHORT_RECORD
FRMLMRCO	FOURMILE CREEK AT LOGAN MILL ROAD NEAR CRISMAN, CO	0.2	28%	0	-0	-0	4.4	SHORT_RECORD
SPSCSFCO	SOUTH PLATTE SUPPLY CANAL SADDLE 8FT FLUME	13.9	56%	0	+5	-38	13.7	SHORT_RECORD
RURDITCO	RURAL DITCH	10.0	64%	0	-1	-4	11.8	SHORT_RECORD
BOC109CO	BOULDER CREEK AT 109 ST NEAR ERIE, CO	6.0	40%	0	-0	-7	10.1	SHORT_RECORD
IDACRKCO	IDAHO CREEK DIVERSION FROM BOULDER CREEK	0.4	5%	0	-1	+0	7.8	SHORT_RECORD
GODHSSCO	GODDING - HIGHLAND SOUTH SIDE DIVERSION	0.0	0%	0	+0	+0	8.2	SHORT_RECORD
PNMAINCO	PANAMA RESERVOIR INLET	0.1	2%	0	+0	-2	6.4	SHORT_RECORD
PNMOUTCO	PANAMA RESERVOIR OUTLET	0.2	14%	0	+0	+0	6.2	SHORT_RECORD
HOWDITCO	HOWARD DITCH	2.4	55%	0	-2	-2	6.4	SHORT_RECORD
GRNDITCO	GREEN DITCH	0.2	7%	0	+0	-1	5.7	SHORT_RECORD
ANDDITCO	ANDERSON DITCH	3.4	82%	0	-0	-0	5.8	SHORT_RECORD
SCRDITCO	SCHEARER DITCH	0.0	0%	0	-1	+0	6.2	SHORT_RECORD
LCWDITCO	LEYNER COTTONWOOD DITCH	0.0	0%	0	+0	+0	6.0	SHORT_RECORD
DC2DITCO	DRY CREEK NO 2 DITCH	0.0	0%	0	+0	+0	5.7	SHORT_RECORD
EG1DITCO	EGGLESTON 1 DITCH	0.0	0%	0	+0	+0	5.8	SHORT_RECORD
EABDITCO	EAST BOULDER DITCH	0.0	0%	0	+0	-1	5.8	SHORT_RECORD
JODDITCO	JONES DONNELLY DITCH OFF LEGGETT INLET	0.3	8%	0	-3	-8	5.8	SHORT_RECORD
LHDDITCO	LH DAVIDSON DITCH	0.0	0%	0	+0	+0	4.7	SHORT_RECORD
BWCDITCO	BOULDER & WELD COUNTY DITCH	3.0	43%	0	-3	-6	5.2	SHORT_RECORD
BWRTO1CO	BOULDER AND WHITEROCK DITCH TURNOUT #1	0.0	0%	0	+0	-15	5.0	SHORT_RECORD
LVROUTCO	LEGGETT-VALMONT RESERVOIR OUTLET	0.0	0%	0	+0	+0	4.9	SHORT_RECORD
DCDDITCO	DRY CREEK DAVIDSON DITCH	0.0	5%	0	-0	-0	4.0	SHORT_RECORD
0600564A	COMMUNITY DITCH, DIVERSION FROM SOUTH BOULDER CREEK	0.0	0%	0	+0	+0	1.4	SHORT_RECORD
BOCBROCO	BOULDER CREEK BELOW BROADWAY STREET	12.7	73%	0	-2	-9	4.2	SHORT_RECORD
MSVDITCO	MARSHALLVILLE DITCH	0.0	1%	0	-0	+0	4.4	SHORT_RECORD
BMLDITCO	BUTTE MILL DITCH	0.9	15%	0	-3	-9	4.3	SHORT_RECORD
DAVDITCO	DAVIDSON DITCH	0.0	0%	0	+0	+0	4.4	SHORT_RECORD
BLDLHDCO	BOULDER LEFT HAND DITCH	0.0	0%	0	-0	-6	4.3	SHORT_RECORD
MCGDITCO	MCGINN DITCH	0.0	1%	0	-1	-2	2.9	SHORT_RECORD
NBFDITCO	NORTH BOULDER FARMERS DITCH	0.0	0%	0	+0	-6	4.2	SHORT_RECORD
GRNRTNCO	GREEN DITCH RETURN TO BOULDER CREEK	0.0	5%	0	+0	-0	4.1	SHORT_RECORD
SMEMDICO	SMITH EMMONS DITCH	0.0	0%	0	+0	+0	2.8	SHORT_RECORD
SBCHOWCO	SOUTH BOULDER CREEK ABOVE HOWARD DITCH	3.1	31%	0	-6	-12	3.5	SHORT_RECORD
SILDITCO	SILVER LAKE DITCH	0.0	0%	0	+0	-0	1.4	SHORT_RECORD
BOCBBRCO	MIDDLE BOULDER CREEK BELOW BARKER MEADOW RESERVOIR	4.3	25%	0	-3	+0	3.8	SHORT_RECORD
NBFRTNCO	NORTH BOULDER FARMERS DITCH RETURN TO BOULDER CREEK	0.0	0%	0	+0	+0	4.0	SHORT_RECORD
FARDTACO	FARMERS DITCH TAIL	0.0	0%	0	+0	+0	3.9	SHORT_RECORD
0603392A	STROMQUIST PONDS INLET	0.0	0%	0	+0	+0	1.6	SHORT_RECORD
ANFDITCO	ANDREWS FARWELL DITCH	0.0	0%	0	+0	+0	3.7	SHORT_RECORD
BOCWLMCO	BOULDER CREEK BELOW WELLMAN DITCH	15.4	74%	0	-2	-8	3.3	SHORT_RECORD
WLMTALCO	WELLMAN DITCH TAIL	0.2	15%	0	-0	-0	3.4	SHORT_RECORD
WLMDITCO	WELLMAN DITCH	0.0	0%	0	+0	+0	3.4	SHORT_RECORD
COCABCCO	COAL CREEK ABOVE BOULDER CREEK CONFULENCE	6.2	37%	0	-2	-0	2.8	SHORT_RECORD
SILOUTCO	SILVER LAKE OUTLET	14.9	45%	0	-2	-14	2.4	SHORT_RECORD
BOCYPLCO	BOULDER CITY PIPELINE	6.8	30%	0	-2	-2	2.7	SHORT_RECORD
LHCPINCO	LIGHTHOUSE COVE POND INLET	0.0	0%	0	+0	+0	5.2	SHORT_RECORD
LUVPPLCO	LOUISVILLE PIPELINE	2.9	98%	0	-0	+0	1.7	SHORT_RECORD
BOCEFFCO	CITY OF BOULDER EFFLUENT RELEASE TO BOULDER CREEK	15.8	82%	0	-0	+0	1.4	SHORT_RECORD
FARDITCO	FARMERS DITCH	0.0	0%	0	-0	-0	5.9	SHORT_RECORD
LEGDITCO	LEGGETT DITCH	11.3	59%	5	-2	-2	16.8	SHORT_RECORD
LWBDITCO	LOWER BOULDER DITCH	29.3	78%	19	+1	-48	4.0	SHORT_RECORD
BWRDITCO	BOULDER AND WHITE ROCK DITCH	0.3	46%	32	+0	-0	6.2	SHORT_RECORD
HONDITCO	HOWELL DITCH NORTH FLUME	0.0	67%	33	+0	+0	4.1	SHORT_RECORD
DRYABCCO	DRY CREEK CARRIER DITCH ABOVE BOULDER CREEK CONFLUENCE	4.5	92%	33	+1	+4	1.5	SHORT_RECORD
ENPLATCO	ENTERPRISE LATERAL DITCH	0.1	75%	37	-0	-0	3.3	SHORT_RECORD
GOOPLMCO	GODDING A AND D PLUMB DITCH	7.3	94%	43	+0	+0	14.4	SHORT_RECORD
COTDITCO	COTTONWOOD DITCH 2	0.8	93%	46	-0	-0	3.9	SHORT_RECORD
SBCABCCO	SOUTH BOULDER CREEK BELOW VALMONT RESERVOIR INLET	0.4	0%	50	-0	-0	0.4	SHORT_RECORD
FILOUTCO	FILLY LAKE OUTLET	0.5	0%	50	+0	+0	0.3	SHORT_RECORD
SIXINLCO	SIX MILE RESERVOIR INLET	0.0	0%	50	+0	+0	0.3	SHORT_RECORD
ERNWEFCO	ERIE NORTH WATER EFFLUENT	0.0	0%	50	+0	+0	0.9	SHORT_RECORD
LF4DIVCO	LAFAYETTE DIVERSION PT 4	3.1	100%	50	-0	+1	4.4	SHORT_RECORD
ENPDITCO	ENTERPRISE DITCH	3.0	278%	63	-0	+1	5.6	SHORT_RECORD
BASOUTCO	BASELINE RESERVOIR OUTLET	3.8	177%	71	+0	+3	3.7	SHORT_RECORD
GDHDITCO	GOODHUE DITCH	0.0	0%	72	-0	+0	3.9	SHORT_RECORD
BWRTO2CO	BOULDER AND WHITEROCK DITCH TURNOUT #2	0.0	0%	75	-0	-5	5.0	SHORT_RECORD
MILVINCO	MILAVEC RESERVOIR INLET (AKA LOWER BOULDER EXT RES.)	0.5	0%	81	-0	+0	5.9	SHORT_RECORD
MCCDITCO	MCCARTY DITCH	0.9	121%	93	-0	-0	2.2	SHORT_RECORD
SMGDITCO	SMITH GOSS DITCH	1.5	174%	97	-0	-0	2.8	SHORT_RECORD
HOSDITCO	HOWELL DITCH SOUTH FLUME	2.6	3924%	100	+0	+1	4.1	SHORT_RECORD
HOWRTNCO	HOWARD DITCH RETURN STRUCTURE	0.5	178%	100	-0	-0	2.4	SHORT_RECORD
SIXOUTCO	SIX MILE RESERVOIR OUTLET	16.4	221%	100	-1	+16	1.1	SHORT_RECORD
MOFTUNCO	MOFFAT WATER TUNNEL AT EAST PORTAL, CO.	8.3	15%	0	-0	-12	82.5	OK
BOCOROCO	BOULDER CREEK NEAR ORODELL, CO.	15.9	29%	0	-2	-17	117.9	OK
BOCNORCO	BOULDER CREEK AT NORTH 75TH ST. NEAR BOULDER, CO	36.7	44%	0	-4	-65	39.9	OK
BOCLONCO	BOULDER CREEK AT MOUTH NEAR LONGMONT, CO	1.1	26%	0	+0	-1	73.8	OK
BOCMIDCO	MIDDLE BOULDER CREEK AT NEDERLAND, CO.	7.0	24%	0	-1	-9	118.6	OK
BOCBGRCO	SOUTH BOULDER CREEK BELOW GROSS RESERVOIR	10.1	6%	0	-26	-60	58.9	OK
BOCELSCO	SOUTH BOULDER CREEK NEAR ELDORADO SPRINGS, CO.	9.1	33%	0	-7	-13	126.9	OK
BOSDELCO	SOUTH BOULDER CREEK DIVERSION NEAR ELDORADO SPRINGS	0.0	0%	0	-20	-46	61.5	OK
BCSCBCCO	BOULDER CREEK SUPPLY CANAL TO BOULDER CREEK ABOVE ERIE TURNOUT	29.1	66%	25	-5	-65	60.6	OK