Computed 2026-08-20 09:22 from 55 gage(s) with cached period-of-record data. Statistical tests (Mann-Kendall trend, Pettitt changepoint) require at least 8 years spanning at least 10 years of record -- gages below that report no signal, not "no change."

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 45 day(s) old (target 7)
diversion record	stale	newest diversion record is 469 day(s) old (DWR publishes ~1 year in arrears)
structure coverage	sparse	25% of schematic structures have data

Independent check: PASS — 100.0000% agreement across 147,489 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 — 99.81% day-level agreement with USGS's own published records for the same gages, across 31 co-listed station(s) and 174,495 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.

55 gage(s) / 392,366 daily values (1901-10-01–2026-07-06); 941 structure(s) with diversion records; 3293 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.

Read this first: the measurement network itself evolved

This basin was not always measured the way it is today — the API-era record is dense and recent, the early record sparse. 9 gage(s) and 490 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1974. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Decade	Gages with data (median yr)	Structures reporting (median yr)
1900s	3	0
1910s	3	0
1920s	1	0
1930s	1	0
1940s	2	0
1950s	4	54
1960s	10	108
1970s	34	317
1980s	26	304
1990s	14	478
2000s	9	567
2010s	9	385
2020s	9	250

Gage flow trend & changepoints

Every located gage with a period of record — dot size scales with the strength of its flow trend (|Sen slope| in %/decade, the same statistic as the table below), color with direction. An amber ring marks a detected Pettitt changepoint. Click a gage to chart its trend and shift.

Gage	Trend	Change / decade	Significance	Years	Changepoint
▸ CORRAL GULCH BELOW WATER GULCH, NR RANGELY, CO.☆ CORWATCO	↑ increasing	+160.7%	p=0.013	16	~1982
▸ CORRAL GULCH NEAR RANGELY, CO☆ CORNRACO	↓ decreasing	-45.1%	p=0.000	53	~2001
▸ YELLOW CREEK NEAR WHITE RIVER, CO.☆ YELWHICO	↓ decreasing	-27.4%	p=0.000	49	~2004
▸ WHITE RIVER BELOW BOISE CREEK, NEAR RANGELY, CO.☆ WHIBOICO	↓ decreasing	-23.0%	p=0.000	44	~2000
▸ PICEANCE CREEK BL RYAN GULCH, NR RIO BLANCO, CO.☆ PICRYACO	↓ decreasing	-22.1%	p=0.001	60	~1998
▸ PICEANCE CREEK AT WHITE RIVER, CO☆ PICRAWCO	↓ decreasing	-18.7%	p=0.010	57	~1999
▸ WHITE RIVER NEAR MEEKER, CO.☆ WHIMEECO	↓ decreasing	-1.6%	p=0.004	122	~1933

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

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 25% of 832 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 (1952–2026)

Mass-balance kinks computed for every summer month back to 1952 (2381 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.

• NORTH FORK WHITE RIVER NEAR BUFORD, CO.: reach shifted from +367 cfs to -46 cfs summer mean (more losing, p=0.019, 17 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=-0.42) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• SOUTH FORK WHITE RIVER AT BUDGES RESORT, CO.: reach shifted from +179 cfs to -361 cfs summer mean (more losing, p=0.003, 21 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=-0.65) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• LOST CREEK NEAR BUFORD, CO.: reach shifted from -8 cfs to -382 cfs summer mean (more losing, p=0.001, 25 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
• PICEANCE CREEK AT WHITE RIVER, CO: reach shifted from -104 cfs to -621 cfs summer mean (more losing, p=0.000, 57 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [measurement-evolution caution: this shift co-moves with the growth of the gage/metering network (rho=-0.54) -- part of it may be unaccounted water becoming accounted, not hydrologic change]

Groundwater now has its own tab: 438 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 137 reservoir(s), end-of-year storage back to 1962, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 65-year window with full coverage (1962–2026), the dominant shared pattern across 3 gage(s) explains 99% 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.

The basin's aquifer story, from 24,232 water-level measurements across 438 monitored well(s) (302 alluvial, 34 bedrock, rest unclassified) — plus 31 administered well(s) reporting metered pumping through diversion records. Observation wells and pumping wells are different populations and are never conflated. Click a well to chart its record.

Well map

Every monitored well with a location — hover for identity, click to chart its water-level record below. ● alluvial   ● bedrock / confined (Denver Basin, High Plains, etc. — one-way, no human-timescale recharge)   ● unclassified — marker size scales with the strength of the well's water-level trend (|Sen slope| in ft/decade — the same Mann-Kendall/Sen statistic as the trends table below); the smallest, faintest dots have too little record to test.

3D aquifer x-ray

Every aquifer unit as its own 3D head surface — alluvial water table on top, Denver Basin members (Dawson, Denver, Arapahoe, Laramie–Fox Hills) stacked beneath where measured — interpolated from measured water levels and animated through time. Units are never mixed; surfaces exist only inside each unit's well coverage (no extrapolation); thin epochs are suppressed with their reason shown. Vertical scale exaggerated for readability; z is head elevation in feet. Advisory — measured heads, not a calibrated model.

Load 3D x-ray

Water-table trends

Of 40 well(s) with enough record for a trend test: 16 declining, 7 rising.

Fastest-declining wells	Setting	ft / decade	Span	p
▸ SC00109814ADC2 TH 75-6B ☆	unknown	-15.36	36 yr	0.0001
▸ WS-14B☆	bedrock	-9.27	48 yr	0.0
▸ WS-06A☆	bedrock	-5.45	48 yr	0.0
▸ WS-04☆	bedrock	-4.32	54 yr	0.0
▸ WS-06B☆	bedrock	-3.65	48 yr	0.0001
▸ WS-20☆	bedrock	-1.85	52 yr	0.0
▸ WS-12☆	bedrock	-1.57	51 yr	0.0
▸ WS-08A☆	bedrock	-1.4	49 yr	0.0046

Stream corridors — the surface connection

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.

NORTH FORK WHITE RIVER NEAR BUFORD, CO.: 8 alluvial well(s) nearby

LOST CREEK NEAR BUFORD, CO.: 5 alluvial well(s) nearby

PICEANCE CREEK AT WHITE RIVER, CO: 5 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.

137 reservoir(s) with 10,886 storage measurement(s), 1962–2026. Basin storage as of 2025-10-31 (the record's own end — reservoir records publish ~annually): 7,985 AF across 51 reservoir(s). 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?

Each reservoir drawn as a vessel: bubble size ∝ its record-high storage, fill level = 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 of its own record high otherwise (a wrong capacity would be worse than an honest record high, so only confident joins upgrade). Hover for numbers, click to chart its history below the map. A dashed teal ring marks reservoirs reporting live DWR telemetry — their fill reflects yesterday's storage, drawn as a dotted tail on charts and treated as provisional until the next verified HydroBase snapshot supersedes it. ● <25% ● 25–60% ● 60–90% ● >90%

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 reservoir to chart its full storage history.

Reservoir	Last recorded storage (AF)	As of
▸ MOON LAKE PL (4302132) ☆	13,800	2002-10-31
▸ TAYLOR DRAW RES (4304433) ☆	6,578	2025-10-31
▸ JOHNNIE JOHNSON RESERVOIR (4303642) ☆	789	2025-10-31
▸ TAYLOR DRAW PWR CONDUIT (4302571) ☆	620	2013-05-02
▸ RIO BLANCO LAKE FDR (4301120) ☆	500	2002-10-28
▸ SKINNY FISH RESERVOIR (4303659) ☆	301	2018-08-13
▸ MCGINNIS MEADOW RES (4303651) ☆	87	2015-09-11
▸ GREENO DITCH 2 (4302474) ☆	81	2002-10-31

Decrees, seniority, and administrative calls connected to this basin's flow network. Advisory reading aids on public DWR data — not administrative or legal conclusions. Rights on file: 4401 across 3293 structure(s); 204 structure(s) carry 0 court-case references.

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 ~1974 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• MACLEAR NO 2 DITCH (4300786)☆ (1935-07-01, 0.8 cfs decreed): last active 1966 — 59 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• STORY SPRING 2 (4301138)☆ (1986-10-10, 0.0 cfs decreed): last active 1968 — 57 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• GRIFFITH DITCH NO 1 (4300667)☆ (1887-05-01, 0.3 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• SYLVAN SPRING (4301153)☆ (1987-05-23, 0.0 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• MOO POND SPRING (4301154)☆ (1987-05-23, 0.0 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• FEED YARD SPRING 2 (4301155)☆ (1970-04-17, 0.0 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• FEED YARD SPRING 3 (4301156)☆ (1972-05-10, 0.2 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• FEED YARD SPRING 4 (4301157)☆ (1974-10-04, 0.1 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• ROJO SPRING PL 1 (4301158)☆ (1955-06-25, 0.0 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse
• ROJO SPRING PL 2 (4301159)☆ (1955-06-25, 0.0 cfs decreed): last active 1969 — 56 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1974) -- early absence of record is weak evidence of nonuse

Compliance screens (522 advisory flags)

Screened 732 of 3293 structures with rights (850 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.

• FULTON IRR & FEEDER D (4300649)☆: Observed p99 daily rate 140.0 cfs (max 160.0) exceeds total decreed absolute 2.0 cfs across 13913 recorded day(s).
• MILLER CREEK DITCH (4300819)☆: Observed p99 daily rate 125.0 cfs (max 141.4) exceeds total decreed absolute 124.0 cfs across 25315 recorded day(s).
• POWELL PARK DITCH (4300883)☆: Observed p99 daily rate 90.0 cfs (max 118.0) exceeds total decreed absolute 82.6 cfs across 41741 recorded day(s).
• STEWART SPRING 1 (4301073)☆: Observed p99 daily rate 67.0 cfs (max 90.0) exceeds total decreed absolute 0.0 cfs across 1420 recorded day(s).
• MCCARTHY SPRING 1 (4301074)☆: Observed p99 daily rate 63.1 cfs (max 84.0) exceeds total decreed absolute 0.0 cfs across 1396 recorded day(s).
• MCDOWELL NO 2 DITCH (4301855)☆: Observed p99 daily rate 62.9 cfs (max 67.9) exceeds total decreed absolute 5.0 cfs across 5491 recorded day(s).
• OLD AGENCY DITCH (4300849)☆: Observed p99 daily rate 62.5 cfs (max 267.0) exceeds total decreed absolute 35.4 cfs across 21498 recorded day(s).
• RAINBOW LAKE DITCH (4300888)☆: Observed p99 daily rate 55.0 cfs (max 55.0) exceeds total decreed absolute 35.0 cfs across 35384 recorded day(s).
• LOWLAND DITCH (4300777)☆: Observed p99 daily rate 46.0 cfs (max 46.0) exceeds total decreed absolute 8.4 cfs across 13400 recorded day(s).
• SOUTH SIDE HIGHLINE D (4300935)☆: Observed p99 daily rate 38.1 cfs (max 57.0) exceeds total decreed absolute 33.0 cfs across 26338 recorded day(s).

Seniority (top structures by decreed rate)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Decreed abs (AF)	Conditional?
TAYLOR DRAW PWR CONDUIT (4302571)☆	1962-07-03	2	745.0	0	yes
HIGHLAND DITCH (4300694)☆	1886-05-01	7	249.0	0	—
WHITE RIVER MSF (4301845)☆	1977-11-15	1	200.0	0	—
MEEKER POWER DITCH (4300809)☆	1911-03-15	3	180.0	0	—
OAK RIDGE PARK DITCH (4300848)☆	1887-12-20	7	133.0	0	—
MILLER CREEK DITCH (4300819)☆	1896-06-01	5	124.0	0	yes
NORTH FORK WHITE RIVER MSF MARVINE CREEK (4302338)☆	1977-11-15	1	120.0	0	—
NIBLOCK DITCH (4300842)☆	1885-03-08	10	99.0	0	yes
POWELL PARK DITCH (4300883)☆	1880-05-01	4	82.6	0	—
SOUTH FORK WHITE R MSF (4302344)☆	1977-11-15	1	80.0	0	—
NORTH FORK WHITE RIVER ( (4303358)☆	2019-01-29	1	74.0	0	—
NORTH FORK WHITE RIVER MSF RIPPLE CK TO (4302339)☆	1977-11-15	1	70.0	0	—
COAL CREEK MESA DITCH (4300578)☆	1883-05-14	9	63.0	0	—
MARVINE CREEK MINIMUM STREAM FLOW (4302334)☆	1977-11-15	1	40.0	0	—
OLD AGENCY DITCH (4300849)☆	1884-04-20	5	35.4	0	—

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

If a call were placed at a given seniority, which structures in this basin would be out of priority, and how much of their decreed rate would be curtailed? Computed from this basin's cached decrees.

Pick a calling right

Real decrees from this basin, ordered by administration number — that is, by actual seniority. The years will look out of order, and that is correct: an administration number encodes the adjudication date as well as the appropriation date, so a right appropriated in 1970 can be administered ahead of one from 1950. A senior call curtails almost everything; a junior one curtails almost nothing.

Or enter an administration number directly

Administration number
Simulate

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