Computed 2026-08-20 09:13 from 12 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 658 day(s) old (DWR publishes ~1 year in arrears)
structure coverage	sparse	23% of schematic structures have data

Independent check: PASS — 100.0000% agreement across 108,117 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 — 99.78% day-level agreement with USGS's own published records for the same gages, across 11 co-listed station(s) and 94,477 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.

12 gage(s) / 95,577 daily values (1904-10-01–2026-07-06); 217 structure(s) with diversion records; 360 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. 3 gage(s) and 98 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1985. Every historical claim below is checked against this: long-term shifts that co-move with the growth of the network carry an explicit measurement-evolution caution, and abandonment screens whose idleness begins before the modern reporting era are flagged †.

Decade	Gages with data (median yr)	Structures reporting (median yr)
1900s	1	0
1920s	1	0
1930s	4	0
1940s	1	0
1950s	4	0
1960s	6	0
1970s	2	38
1980s	2	92
1990s	4	130
2000s	2	151
2010s	2	132
2020s	3	95

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
▸ MUDDY CREEK AT KREMMLING, CO.☆ MUDATKCO	↓ decreasing	-80.2%	p=0.021	14	~1986
▸ MUDDY CREEK NEAR KREMMLING, CO.☆ MUDNEKCO	↑ increasing	+14.1%	p=0.003	28	~1956

10 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: 23% of 133 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 (1990–2026)

Mass-balance kinks computed for every summer month back to 1990 (159 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.

No reach shows a statistically significant long-term gain/loss shift.

Reservoirs now has its own tab: 53 reservoir(s), end-of-year storage back to 1975, click-to-chart histories.

Cross-gage pattern fingerprint

Not enough gages with a long enough common-coverage window yet to fingerprint shared patterns.

53 reservoir(s) with 6,758 storage measurement(s), 1975–2025. Basin storage as of 2024-10-31 (the record's own end — reservoir records publish ~annually): 55,955 AF across 13 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
▸ WOLFORD MOUNTAIN RESERVOIR (5003668) ☆	54,555	2024-10-31
▸ ADOLPH DITCH (5000500) ☆	36,254	2019-10-31
▸ MCMAHON RESERVOIR NO 1 (5003628) ☆	750	1982-10-11
▸ MCMAHON RESERVOIR NO 2 (5003629) ☆	550	2024-10-17
▸ HINMAN RESERVOIR (5003618) ☆	450	2024-10-29
▸ LAKE AGNES (5003623) ☆	295	2019-10-31
▸ WHITELY PEAK RESERVOIR (5003642) ☆	250	2021-10-31
▸ DUMONT LAKE (5003666) ☆	240	2021-10-31

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: 530 across 360 structure(s); 28 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 ~1985 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• OAKS RESERVOIR (5003631)☆ (1890-09-30, 0.0 cfs decreed): last active 1976 — 48 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1985) -- early absence of record is weak evidence of nonuse
• PARSONS RESERVOIR (5003632)☆ (1944-11-11, 0.0 cfs decreed): last active 1976 — 48 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1985) -- early absence of record is weak evidence of nonuse
• WHEATLEY DIVERSION WORKS POND NO 1 (5003640)☆ (1889-06-01, 0.0 cfs decreed): last active 1976 — 48 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1985) -- early absence of record is weak evidence of nonuse
• WHITELY PEAK RESERVOIR (5003642)☆ (1940-04-15, 0.0 cfs decreed): last active 1976 — 48 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1985) -- early absence of record is weak evidence of nonuse
• MARTIN PUMP NO 2 DITCH (5000602)☆ (1887-04-21, 8.5 cfs decreed): last active 1979 — 45 years idle † predates modern reporting era — last recorded activity predates this basin's modern reporting era (~1985) -- early absence of record is weak evidence of nonuse
• ALPHA DITCH (5000508)☆ (1903-06-01, 2.0 cfs decreed): last active 1985 — 39 years idle
• BECKER AND HEINI DITCH (5000521)☆ (1887-09-21, 3.5 cfs decreed): last active 1995 — 29 years idle
• LYONS VAUGHAN WELL NO 1 (5005006)☆ (1966-08-02, 0.1 cfs decreed): last active 2000 — 24 years idle
• LYONS VAUGHAN WELL NO 2 (5005007)☆ (1959-08-01, 0.1 cfs decreed): last active 2000 — 24 years idle
• CURRAN SPRINGS (5000694)☆ (1969-09-29, 0.2 cfs decreed): last active 2001 — 23 years idle

Compliance screens (121 advisory flags)

Screened 158 of 360 structures with rights (196 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.

• MIN FLOW MUDDY CREEK (5002000)☆: Observed p99 daily rate 105.0 cfs (max 105.0) exceeds total decreed absolute 20.0 cfs across 4413 recorded day(s).
• HARDSCRABBLE DITCH (5000574)☆: Observed p99 daily rate 35.5 cfs (max 57.0) exceeds total decreed absolute 32.0 cfs across 12299 recorded day(s).
• BECKER NO 2 DITCH (5000516)☆: Observed p99 daily rate 32.4 cfs (max 35.1) exceeds total decreed absolute 6.0 cfs across 6616 recorded day(s).
• TROUBLESOME DITCH (5000654)☆: Observed p99 daily rate 32.0 cfs (max 41.3) exceeds total decreed absolute 23.5 cfs across 16018 recorded day(s).
• BECKER NO 5 DITCH (5000519)☆: Observed p99 daily rate 28.6 cfs (max 28.6) exceeds total decreed absolute 1.3 cfs across 2466 recorded day(s).
• BLICKLEY DITCH (5000526)☆: Observed p99 daily rate 28.0 cfs (max 31.0) exceeds total decreed absolute 18.7 cfs across 6828 recorded day(s).
• MCMAHON DITCH (DEER CR) (5000762)☆: Observed p99 daily rate 27.0 cfs (max 30.0) exceeds total decreed absolute 18.0 cfs across 4912 recorded day(s). Structure holds an Augmentation-use decree -- diversions above the direct-flow decree can be lawful under plan operations; interpret with care.
• HERDE DITCH (5000582)☆: Observed p99 daily rate 23.3 cfs (max 30.0) exceeds total decreed absolute 12.2 cfs across 7773 recorded day(s). Structure holds an Augmentation-use decree -- diversions above the direct-flow decree can be lawful under plan operations; interpret with care.
• PICKERING DITCH (5000628)☆: Observed p99 daily rate 20.0 cfs (max 33.1) exceeds total decreed absolute 9.5 cfs across 8308 recorded day(s).
• MCELROY NO 1 PUMP (5000612)☆: Observed p99 daily rate 18.0 cfs (max 18.0) exceeds total decreed absolute 12.0 cfs across 4156 recorded day(s).

Seniority (top structures by decreed rate)

Structure	Senior priority date	Rights	Decreed abs (cfs)	Decreed abs (AF)	Conditional?
MISSOURI DITCH (5000606)☆	1892-06-02	7	98.0	0	—
KURTZ DITCH NO 2 (5000593)☆	1892-06-02	3	88.5	0	yes
DEBERARD DITCH OVERFLOW SYSTEM (5000734)☆	1883-06-05	6	80.7	0	—
HAYPARK CANAL HGT NO 1 (5000576)☆	1959-08-05	1	75.0	0	yes
MCMAHON DITCH (5000617)☆	1884-08-15	8	72.0	4022	—
TOM ENNIS DITCH (5000653)☆	1883-05-01	3	62.3	0	—
SARVIS DITCH (5004600)☆	1911-05-24	2	43.0	1627	—
MARTIN NO 1 DITCH (SOUTH FORK HGT) (5000601)☆	1890-06-30	2	33.5	0	—
MARTIN LILY POND FEEDER DITCH (5000768)☆	1939-05-27	2	33.5	0	—
HARDSCRABBLE DITCH (5000574)☆	1883-06-05	6	32.0	611	—
CLIFF DITCH (5000539)☆	1886-05-31	2	31.3	0	—
HOGBACK DITCH (5000585)☆	1885-04-30	25	26.9	615	—
PINTO CREEK DITCH (5000631)☆	1896-12-01	2	24.0	0	—
TROUBLESOME DITCH (5000654)☆	1889-09-21	1	23.5	0	—
MIN FLOW MUDDY CREEK (5002000)☆	1998-07-13	1	20.0	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.