Hydrohistorian
Bootstrap review report — d6_wd55_little_snake_river
Generated 2026-08-15 15:55 UTC for Division 6 / Water District 55.
This is a review checklist, not a finished config. Everything below is a suggestion from live DWR data — confirm or correct each section in config.yaml before running this basin for real.
1. Stream-name patterns
Assumed mainstem pattern: LITTLE SNAKE RIVER (highest-count waterSource value). Candidates below by structure count — decide which are real tributaries worth their own centerline vs. noise, and add them to longitudinal.tributary_stream_patterns in priority order (more-specific names, e.g. "WEST FORK X", must precede substrings of themselves, e.g. "X").
| waterSource | structure count |
|---|---|
| LITTLE SNAKE RIVER (assumed mainstem) | 26 |
| YAMPA RIVER | 4 |
| TURNERS CREEK | 4 |
| THE SLOUGH | 3 |
2. Diversion / return classification
Auto-classified from structureType + name patterns: 40 diversions, 0 returns, 3 unclassified (neither pattern matched — these render as neither on the schematic unless added to return_flow_wdids/force_diversion_wdids or a type is added to the diversion/return type lists).
This layer needs the least manual work — it's the same heuristic the engine uses at runtime. Spot-check a sample rather than reviewing every row; if you have a water-year accounting spreadsheet for this basin, cross-reference it against the 'other' bucket specifically (that's where a real augmentation return with an unusual DWR structureType will hide).
2b. Cross-checked against decreed water rights (CDSS)
2 structure(s) have a decreed water right (CDSS waterrights/netamount) that disagrees with the structureType/name-pattern classification above. Same-agency evidence (DWR/HydroBase), not independent of DWR the way the NLDI topology check is — worth a glance, not an automatic correction.
| wdid | structure | currently | decreed uses suggest | decreed uses |
|---|---|---|---|---|
| 5505014 | POWDER WASH UNIT WELL NO. 1 DEEP WATER WELL | other | diversion | Industrial |
| 5506003 | ARAMBEL WELL 2 | other | diversion | Domestic, Industrial, Irrigation |
3. Suspected nested tributaries
3 flag(s) confirmed connected by USGS NLDI — real surveyed stream-network topology, not a distance guess (see VERIFICATION-PLAN.md). This confirms the two candidates' channels really do merge (ruling out a coincidental-proximity false flag) but NOT auto-applied to tributary_parent_overrides — NLDI's overlap test can't reliably tell which side is upstream once two streams have already merged near DWR's own recorded structures, only that they connect. Confirm the direction (which one is the tributary, which is the parent) from local knowledge or the evidence below, then set it yourself.
| pair | NLDI evidence |
|---|---|
| YAMPA RIVER <-> TURNERS CREEK | tributary's downstream NHD trace (comid 3111221) first overlaps TURNERS CREEK's own downstream trace at index 0 (next-nearest candidate: none) |
| TURNERS CREEK <-> YAMPA RIVER | tributary's downstream NHD trace (comid 3111227) first overlaps YAMPA RIVER's own downstream trace at index 1 (next-nearest candidate: none) |
| THE SLOUGH <-> TURNERS CREEK | tributary's downstream NHD trace (comid 3111753) first overlaps TURNERS CREEK's own downstream trace at index 3 (next-nearest candidate: none) |
4. Gage placement risk
1 gage(s) would currently fail placement (> 2.5mi from the nearest centerline anchor — same failure mode as the Clear Creek at Derby bug). Options: raise the cutoff (check it doesn't sweep in an unrelated stream first — see the Little Dry Creek case), or add a manual override.
| gage | name | nearest stream | distance (mi) |
|---|---|---|---|
| YAMDEECO | YAMPA RIVER AT DEERLODGE PARK, CO | YAMPA RIVER | 3.59 |
4 more gage(s) pass but are within 2x the cutoff distance — worth a glance if the structure dataset changes later.
Next steps
- Fill in
tributary_stream_patternsfrom section 1. - Resolve section 3's flags (or confirm none apply).
- Resolve section 4's at-risk gages.
- Cross-reference
return_flow_wdids/force_diversion_wdidsagainst any local accounting source you have for this basin. - Review the rendered schematic for this district before relying on it.
Evolution of the network
Computed 2026-08-20 09:27 from 6 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 C (3/6 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 | expected-lag | newest diversion record is 309 day(s) old (DWR publishes ~1 year in arrears) |
| structure coverage | sparse | 15% of schematic structures have data |
Independent check: PASS — 100.0000% agreement across 90,869 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 — 98.13% day-level agreement with USGS's own published records for the same gages, across 6 co-listed station(s) and 87,954 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.
6 gage(s) / 88,192 daily values (1921-10-01–2026-07-06); 33 structure(s) with diversion records; 477 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 18 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) |
|---|---|---|
| 1920s | 1 | 0 |
| 1930s | 1 | 0 |
| 1940s | 2 | 0 |
| 1950s | 2 | 0 |
| 1960s | 2 | 0 |
| 1970s | 2 | 11 |
| 1980s | 3 | 13 |
| 1990s | 4 | 17 |
| 2000s | 3 | 18 |
| 2010s | 3 | 18 |
| 2020s | 3 | 16 |
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 |
|---|---|---|---|---|---|
|
▸
YAMPA RIVER AT DEERLODGE PARK, CO YAMDEECO |
↓ decreasing | -28.0% | p=0.002 | 42 | ~2017 |
|
▸
LITTLE SNAKE RIVER NEAR SLATER, CO LSRSLACO |
no clear trend | -2.0% | p=0.329 | 80 | ~2017 |
4 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: 15% of 142 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 (1988–2003)
Mass-balance kinks computed for every summer month back to 1988 (40 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.
Groundwater now has its own tab: 1 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.
Cross-gage pattern fingerprint
Over the 26-year window with full coverage (2001–2026), the dominant shared pattern across 3 gage(s) explains 74% 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 6 water-level measurements across 1 monitored well(s) (0 alluvial, 0 bedrock, rest unclassified) — plus 2 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.
Water-table trends
Of 0 well(s) with enough record for a trend test: 0 declining, 0 rising.
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.
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: 522 across 477 structure(s); 17 structure(s) carry 0 court-case references.
Abandonment radar (4 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).
- ARAMBEL WELL 2 (5506003) (1955-06-15, 0.2 cfs decreed): last active 1986 — 37 years idle
- ESCALANTA DITCH (5500516) (1899-10-01, 6.0 cfs decreed): last active 2003 — 20 years idle
- PERUSEK DITCH (5500510) (1928-09-24, 3.8 cfs decreed): last active 2008 — 15 years idle
- HELLS CANYON DITCH (5502035) (1920-07-01, 7.0 cfs decreed): last active 2013 — 10 years idle
Compliance screens (10 advisory flags)
Screened 25 of 477 structures with rights (30 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.
- RAFTOPOULOS LSR PUMP (5501081): Observed p99 daily rate 14.0 cfs (max 14.0) exceeds total decreed absolute 11.8 cfs across 6296 recorded day(s).
- LEFEVRE NO 1 PUMP (5500537): Observed p99 daily rate 11.3 cfs (max 15.0) exceeds total decreed absolute 10.0 cfs across 6839 recorded day(s).
- NINE MILE IRR DITCH (5500507): Observed p99 daily rate 10.0 cfs (max 10.0) exceeds total decreed absolute 8.0 cfs across 5726 recorded day(s).
- PERUSEK DITCH (5500510): Observed p99 daily rate 10.0 cfs (max 18.8) exceeds total decreed absolute 3.8 cfs across 2008 recorded day(s).
- HAYSTACK PUMP (5502034): Observed p99 daily rate 9.3 cfs (max 10.0) exceeds total decreed absolute 6.7 cfs across 1514 recorded day(s).
- NINE MILE IRR PL (5500508): Observed p99 daily rate 8.0 cfs (max 8.0) exceeds total decreed absolute 6.5 cfs across 6536 recorded day(s).
- GORDON C. WINN PUMP 1 (5500514): Observed p99 daily rate 8.0 cfs (max 8.0) exceeds total decreed absolute 2.2 cfs across 6158 recorded day(s).
- ADOLPH EDINGER D & PL (5500502): Observed p99 daily rate 4.1 cfs (max 4.7) exceeds total decreed absolute 4.0 cfs across 384 recorded day(s).
- STUDEBAKER PUMP (5502037): Observed p99 daily rate 3.0 cfs (max 3.0) exceeds total decreed absolute 2.0 cfs across 2324 recorded day(s).
- KAWCAK PUMP EAST (5500558): All rights on this structure are conditional (no absolute decree), but divrec shows 30 day(s) of nonzero diversion -- worth checking whether an absolute right was decreed since the cached net amounts, or the diversions run under another plan.
Seniority (top structures by decreed rate)
| Structure | Senior priority date | Rights | Decreed abs (cfs) | Decreed abs (AF) | Conditional? |
|---|---|---|---|---|---|
| MAJORS PUMP NO 2 (5500506) | 1890-05-01 | 6 | 18.6 | 0 | — |
| ONECO PUMP NO 2 (5500509) | 1890-05-01 | 6 | 15.3 | 0 | — |
| RINKER PUMP D (5500519) | 1916-06-26 | 3 | 12.0 | 0 | — |
| RAFTOPOULOS LSR PUMP (5501081) | 1924-06-01 | 3 | 11.8 | 69 | — |
| LEFEVRE NO 1 PUMP (5500537) | 1975-09-17 | 1 | 10.0 | 0 | — |
| DEWEY SHERIDAN D (5501011) | 1947-04-27 | 1 | 10.0 | 0 | — |
| NINE MILE IRR DITCH (5500507) | 1950-02-17 | 1 | 8.0 | 0 | — |
| GORDON C. WINN PUMP 2 (5500515) | 1963-05-01 | 1 | 7.8 | 0 | — |
| HELLS CANYON DITCH (5502035) | 1920-07-01 | 1 | 7.0 | 0 | — |
| HAYSTACK PUMP (5502034) | 1936-08-01 | 1 | 6.7 | 0 | — |
| NINE MILE IRR PL (5500508) | 1961-08-14 | 2 | 6.5 | 0 | — |
| ESCALANTA DITCH (5500516) | 1899-10-01 | 1 | 6.0 | 0 | — |
| DUNN PUMP & PL (5500538) | 1975-10-01 | 1 | 6.0 | 0 | — |
| VISINTAINER DITCH (5500513) | 1929-09-09 | 2 | 5.0 | 0 | — |
| ONECO DITCH (5501509) | 1901-04-29 | 1 | 4.2 | 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.