Hydrohistorian
Full diagnostic snapshot pending — this district's weekly-style report (system status, active calls, hydrographs, anomaly flags) is produced by the nightly rotation and appears here after its first run. The tabs above are live now.
Evolution of the network
Gage flow trend & changepoints
What counts as a trend here
Computed 2026-08-20 09:13 from 12 gage(s) with cached period-of-record data. Mann-Kendall (trend) 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.”
Of the 12 gages with enough record, 1 is trending down and 1 up, and 2 carry a detected shift. The clearest is MUDDY CREEK NEAR KREMMLING, CO., +14.1 points of its long-term median per decade over 28 years (p=0.0029). The other 10 show no clear signal either way.
| Gage | Trend | Change / decade points of median | 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).
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. 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 |
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.
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.
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).
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.
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 |
Decreed rights on this network run from 1878-09-22 to 2023-10-26. 25 abandonment screens and 121 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: 530 across 360 structure(s); 28 structure(s) carry 0 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.
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.
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
DWR administration numbers encode appropriation and adjudication dates; lower is more senior.