Hydrohistorian
Piedra River Basin
Who may take water from the Piedra River Basin, who is calling for it today, and how it is running, compiled from Colorado Division of Water Resources records. Click anything on the map for its record.
Piedra River Basin on the ground — the ditches, wells, reservoirs and gages of Water District 78 · clicktap anything for its record
The well-permit cells in view, as a table
Each row is one ~1-mile cell (0.02°) with the permits the file spots inside it, split into water-supply permits and monitoring holes (DWR’s two monitoring categories: drilled to look at the water, not to pump it). These are permits, not wells: a permit is a piece of paper, and the file does not say which were drilled. Spotting is the file’s own, about a mile at best, which is why the cells are no finer.
| Lat | Lon | Water-supply permits | Monitoring holes |
|---|
Browse this district’s ditches, gages, reservoirs, wells and springs as a list.
The Piedra River is near normal for late September -- 92% of normal flow, its 6th-wettest such week in 65 years of record. 1 call stands against it right now; the most senior right calling dates to 1934. DWR's statements do not settle whether 2 more calls reach it. This year's runoff outlook, issued 2026-06-01, called for 24% of normal.
Schematic
Historical
Evolution of the network
Trends
Source Our computation, no independent reference · computed here from the screened DWR record Source Our computation, no independent reference · no independent reference; see /methods
This year, in context
In the weeks around 2026-09-27 (the newest reading on file), flows at the 1 ranked gage are running at a median 481% of their own long-term norm for this window — 0 below a typical year, 1 at or above. Driest relative to its record: PIEDRA RIVER NEAR ARBOLES, CO., ranking 62nd lowest of 65 years.
How this comparison is made
Each gage's mean flow over the 3 days either side of 2026-09-27, 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 2026-10-11 21:16 from 10 gage(s) with cached period-of-record data. The series is each gage's annual mean flow in cfsCubic feet per second, a rate of flow. One cfs running for a day is about 2 acre-feet. (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.
None of the 10 gages with enough record shows a significant trend or a detected shift — which is itself the finding.
No gage shows a statistically significant trend or changepoint yet.
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. 2 gage(s) and 58 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) |
|---|---|---|
| 1930s | 3 | 0 |
| 1940s | 4 | 0 |
| 1950s | 2 | 0 |
| 1960s | 2 | 32 |
| 1970s | 2 | 67 |
| 1980s | 1 | 86 |
| 1990s | 2 | 88 |
| 2000s | 2 | 94 |
| 2010s | 2 | 62 |
| 2020s | 2 | 58 |
Mass-balance (network closure) trend
Structure divrec-history backfill coverage as of the last check: 17% of 249 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 (–)
Mass-balance kinks computed for every summer month back to (0 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: 44 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.
Reservoirs now has its own tab: 28 reservoir(s), end-of-year storage back to 1970, 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 C (3/6 points) — the components below are the finding; the letter alone is not. Sources: DWR HydroBase snapshot HydroBase_CO_20260928 (imported 2026-10-04) for history, plus the CDSS REST API for current conditions.
| Check | State | What was measured |
|---|---|---|
| gage freshness | stale | newest gage reading is 14 day(s) old (target 7) |
| diversion record | expected-lag | newest diversion record is 346 day(s) old (DWR publishes ~1 year in arrears) |
| structure coverage | sparse | 17% of schematic structures have data |
Independent check: PASS — 100.0000% agreement across 154,523 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 — 99.52% day-level agreement with USGS's own published records for the same gages, across 7 co-listed station(s) and 50,101 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.
10 gage(s) / 60,199 daily values (1936-10-01–2026-09-27); 170 structure(s) with diversion records; 371 with decreed rights. Methodology has not yet had independent expert review — treat every figure as an advisory screen, not an administrative or legal conclusion.
Groundwater
Source DWR administrative record · verify at DWR groundwater wells ↗ Source DWR administrative record · verify at DWR well permits ↗
244 water-level measurements across 44 monitored well(s) — 33 alluvial, 0 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 1 well(s) with enough record for a trend test: 1 declining, 0 rising.
| Fastest-declining wells | Setting | ft / decade | Span | p |
|---|---|---|---|---|
| ▸ WS-25 | alluvial | -0.51 | 43 yr | 0.0023 |
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.
33% are constructed wells; 0% tie to a decreed structure. A permit is permission to drill, not a water right; most here are exempt household wells. More in three things called “well”, or turn on the Well permits chip on the map above to see where they sit.
Permits issued here, by year
2 located water-supply permits with an issue date, 2010 to 2020; half of them had been issued by 2010, and the busiest year was 2010 with 1. A permit is not a well, and the year is the date the paper was issued, not a drilling date. The 3 above counts every permit on file here; 1 of them have no usable location or no issue date and are not in this chart.
water-supply permits issued that year
The counts by year, as a table
| Year | Issued | Monitoring holes | Water-supply | Issued through that year |
|---|---|---|---|---|
| 2010 | 1 | 0 | 1 | 1 |
| 2020 | 1 | 0 | 1 | 2 |
Every district in the file on one scale · the whole file, one year at a time · Plate 4 of the Driller’s Atlas.
The Driller’s Atlas · Plate 2 A cross-section nobody surveyed
Every permitted well within a few miles of the line, drawn from the ground to its drilled depth as the driller filed it. The bright part of each stroke is the perforated casing — where the well actually takes water — coloured by the aquifer named on the permit. Nobody arranged these; the aquifers arrange themselves.
The ground each well hangs from is a 1-km elevation model sampled at the point the permit was spotted, so the profile is real topography smoothed to about a kilometre — peaks are shaved, valleys filled a little — and the depths are the driller’s, measured down from that ground.
Hover or arrow through the strokes to read a well.
The same corridor as a table
| Miles from A | Wells drawn | Median depth (ft) | With a screen | Most-named aquifer | No depth filed | Ground, ft above sea level (median) |
|---|
Bins run from end A to end B of the line. “Most-named aquifer” is the family most often named on permits in the bin, with its count; permits naming no aquifer are the majority of the file and are not a family.
Reservoirs
Source DWR administrative record · verify at DWR structure records ↗
28 reservoir(s) with 5,424 storage measurement(s), 1970–2024. Basin storage as of 2023-10-31 (the record's own end — reservoir records publish ~annually): 14,465 AF across 8 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) | |
|---|---|---|---|---|---|
| ▸ WILLIAMS CREEK RESERVOIR (7803642) | 8,482 | 2023-10-31 | — | — | dossier → |
| ▸ STEVENS RESERVOIR DAM (7803645) | 1,825 | 2022-10-31 | — | — | dossier → |
| ▸ G S HATCHER RESERVOIR (7803626) | 1,635 | 2022-10-31 | — | — | dossier → |
| ▸ LINN AND CLARK RESERVOIR (7803629) | 1,239 | 2022-10-31 | — | — | dossier → |
| ▸ TOWN CENTER LAKE (7803646) | 641 | 2022-10-31 | — | — | dossier → |
| ▸ LAKE FOREST (7803644) | 452 | 2022-10-31 | — | — | dossier → |
| ▸ PARGIN RESERVOIR (7803633) | 337 | 2011-10-31 | — | — | dossier → |
| ▸ PINON LAKE (7803636) | 125 | 2022-10-31 | — | — | dossier → |
Snow and runoff
Source Independent agency measurement · fetched 2026-10-16 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record
Snow-water equivalent, WY2027
No snow on the ground — normal for the date; the snow year begins in October. The new water year began October 1; the chart fills in a day at a time as NRCS publishes each reading.
| SNOTEL site | Elev (ft) | SWE (in) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Weminuche Creek | 10730 | 0.0 | 0.0 | — | March 28 (16.4 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 (2011–2026)
A bad snow year here comes in two flavors (both called snow droughtA winter that shorts the snowpack. It happens two ways: a dry one, where the snow never comes, and a warm one, where near-normal snow falls but melts off weeks early -- and the river feels them differently.), and the river feels them differently. In 4 of the last 16 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.
The snow never came: 2018, 2022, 2025, 2026. The snow left early: 2012.
Computed by this site from 1 SNOTEL site’ full daily records (NRCS AWDB, back to 2011). 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 — Piedra R nr Arboles
NRCS's final issue (2026-06-01) calls it even odds that at least 14 kAF arrives over 06-01 to 07-31 — 24% of a normal season; almost certainly at least 6, probably not more than 40. Our own record at this gage shows 8 kAF actually delivered. New forecasts begin in January. How to read these numbers →
We test a record-based adjustment of the April benchmark at every graded point. Here it did not beat NRCS over 68 replayed seasons (14% typical miss unadjusted vs 20% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →
| 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 |
|---|---|---|---|---|---|---|
| 6 | 10 | 14 | 25 | 40 | 58 | 8 |
How good are these forecasts here? (1963–2025)
Grading every April issue against what the river then delivered, measured at this gage’s own record — 62 seasons: the median miss of the 50% forecast is 16%, with a high bias of 2%, and the observed volume landed inside the stated 10–90% band 91% 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 (2011–2026)
Across 16 measured years, the season’s water has closely followed the April snowpack: a year opening April with 80% of median snow has typically gone on to deliver about 73% of a normal season (a snow-to-runoff elasticityHow strongly one number moves with another. A snow-to-runoff elasticity of 1.5 means a 10% shortfall in April snowpack has typically become a 15% shortfall in the season's water. of 0.8). In warm, early-melt years the river delivered a median of 59% of a normal season, against 92% in typical years — the timing of the melt matters, not just its size.
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.
Drought
Source Our computation, no independent reference · computed here from the screened DWR record Source Independent agency measurement · fetched 2026-10-13 · verify at U.S. Drought Monitor ↗
Right now
This is the 60th-driest week 39 in 65 years of record at PIEDRA RIVER NEAR ARBOLES, CO. (as of 2026-09-21; this week’s flow sits at the 92nd percentileRank against the record: a river at its 5th percentile is lower than it was in 95 of the past 100 years on this same date. for the date). On this week’s US Drought Monitor, Hinsdale County is 8% in D3 extreme drought (2026-10-13). The law agrees: the most senior active call leaves 96% of this district’s decreed flow rights junior to the calling right this week.
Every year since 1962, week by week
Each thin row is a year at PIEDRA RIVER NEAR ARBOLES, 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.
This year against its analogs
Over the 32 weeks recorded so far, 2026’s weekly trace most resembles 2025 (mean gap 17.6 percentile points; next closest 2018 (18.4), 2020 (19.7)). The analog’s remainder is drawn as context — its ending is what happened to it, not a forecast for this year.
The Drought Monitor’s view since 2000
Mean share of area in each class across Archuleta, Hinsdale, Mineral 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 2002 — 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 (25 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.
This basin’s droughts, by its own record
| Drought | Span | Weeks | Trough percentile | Flows recovered | Water table back |
|---|---|---|---|---|---|
| unnamed dry spell | 2025-05-05 → 2026-01-26 | 38 | 11th (2025-09-01) | 1 week | — |
| unnamed dry spell | 2023-11-20 → 2024-10-14 | 47 | 14th (2024-01-22) | 68 weeks | — |
| the 2020-22 drought | 2020-04-06 → 2022-09-26 | 129 | 9th (2021-03-15) | 22 weeks | — |
| the 2018 drought | 2018-01-29 → 2019-06-17 | 72 | 6th (2018-10-01) | 1 week | — |
| the 2012-13 drought | 2012-09-17 → 2013-10-21 | 57 | 14th (2013-01-14) | 0 weeks | — |
| unnamed dry spell | 2009-11-30 → 2010-06-07 | 27 | 22nd (2010-02-08) | 9 weeks | — |
| the 2002 drought | 2002-01-07 → 2004-03-15 | 114 | 3rd (2002-07-29) | 14 weeks | — |
| unnamed dry spell | 2000-08-28 → 2001-02-05 | 23 | 24th (2000-10-16) | 7 weeks | — |
| unnamed dry spell | 1996-04-01 → 1996-12-23 | 38 | 20th (1996-08-19) | 5 weeks | — |
| unnamed dry spell | 1989-12-18 → 1990-09-03 | 37 | 11th (1990-04-16) | 0 weeks | — |
| the 1981 drought | 1981-04-13 → 1981-10-05 | 25 | 23rd (1981-06-29) | 2 weeks | not yet (3 of 5 wells still below) |
| the 1977 drought | 1977-02-28 → 1978-01-30 | 48 | 5th (1977-06-20) | 62 weeks | 9 yr (8 wells, 3 still below) |
| unnamed dry spell | 1974-04-22 → 1975-05-05 | 54 | 20th (1974-09-30) | 6 weeks | — |
| unnamed dry spell | 1968-02-12 → 1968-07-29 | 24 | 18th (1968-03-25) | 1 week | — |
Detected mechanically: the 26-week smoothed percentile below the 30th for at least 20 weeks; recovered on regaining the 50th. The water-table clock compares each monitoring well against its own pre-drought median (the 3 years before onset) and dates the year the median well got back — the aquifer remembers longest, and “still below” is a finding, not a gap. 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.
When this basin claimed its water
Every bar is a year’s new appropriations (179 rights across 65 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is +0.05 — 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.
Legal
Who serves it, who protects it
Two registers the site fetches on their own schedules, read for this district. Neither is a DWR record; each links its own page and its agency.
Public water systems here
Source Register of another agency · fetched 2026-10-06 · verify at EPA SDWIS ↗
3 systems touch this district (2 community systems reporting 11,359 people served, a figure that counts a wholesaler's customers twice); none carries an open health-based violation on EPA's record.
| System | Serves | Source | Here |
|---|---|---|---|
| PAGOSA AREA WSD | 11,069 | Surface water | 70% of its area |
| ASPEN SPRINGS MD wholesaler | 290 | Groundwater | 100% of its area |
| WATER RUNNER LLC THE non-community | 67 | Purchased surface water | 100% of its area |
Instream-flow rights held by the state
Source Register of another agency · fetched 2026-10-11 · verify at CWCB instream flow program ↗
12 reaches over 93.1 miles, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →
- Piedra River, 15.0 mi: 70 (3/1 - 8/31), 40 (9/1 - 2/29) cfs (appropriated 1979, 79CW0045) · dossier
- Williams Creek, 13.0 mi: 14 (1/1 - 12/31) cfs (appropriated 1978, 78W1819) · dossier
- Weminuche Creek, 12.0 mi: 9 (1/1 - 12/31) cfs (appropriated 1978, 78W1820) · dossier
- Piedra River, 10.0 mi: 70 (3/1 - 8/31), 40 (9/1 - 2/29) cfs (appropriated 1978, 78W1815) · dossier
- East Fork Piedra River, 9.0 mi: 10 (1/1 - 12/31) cfs (appropriated 1978, 78W1818) · dossier
- Middle Fork Piedra River, 9.0 mi: 11 (1/1 - 12/31) cfs (appropriated 1978, 78W1817) · dossier
and 6 more on the district's instream-flow page.
What the water is like -- USGS sensors right now, where it has been sampled, the impaired-waters list, and how the tap water here stands with EPA -- is on the Water quality tab.
Designated groundwater basins are on their own page.
Source Adjudicated record · verify at DWR water-right transactions ↗ Source Adjudicated record · verify at DWR net amounts ↗
Decreed rights on this network run from 1868-03-02 to 2025-12-17. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 2% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 85 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: 441 across 371 structure(s); 64 structure(s) carry 0 court-case references. Advisory reading aids on public DWR data — not administrative or legal conclusions.
Is the river getting harder to divert from?
Over 2003–2025, administration on this district has been tightening: 1 of 3 measures (days under callA senior water right demanding its water, which requires everyone junior on that stream to stop diverting until it is satisfied., calls set, seniorityColorado shares water by date: the earlier the right, the stronger its claim when the river runs short. "First in time, first in right." 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 (23 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 | 319 | 117 | 1883-05-15 |
| 2015 | 316 | 90 | 1899-05-13 |
| 2016 | 273 | 94 | 1888-02-08 |
| 2017 | 297 | 98 | 1904-01-02 |
| 2018 | 285 | 164 | 1878-05-15 |
| 2019 | 186 | 53 | 1880-06-01 |
| 2020 | 240 | 171 | 1986-11-23 |
| 2021 | 246 | 143 | 1876-11-01 |
| 2022 | 261 | 161 | 1888-03-20 |
| 2023 | 198 | 82 | 1880-06-01 |
| 2024 | 231 | 114 | 1876-10-10 |
| 2025 | 281 | 169 | 1888-03-20 |
Why diversions stopped — call-based explanations
Sustained diversion stops matched to senior administrative calls.
- FARROW AND PETERSON D (7800545) DWR↗ stopped 2025-09-17 (44+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- CARL AND WEBB DITCH (7800523) DWR↗ stopped 2025-09-15 (46+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- F S MOCKLER IRR DITCH (7800544) DWR↗ stopped 2025-09-04 (57+ days) — call at SPRING CREEK DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BIG PAGOSA DITCH (7800510) DWR↗ stopped 2025-09-01 (60+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BARNES-MEUSER AND SHAW D (7800507) DWR↗ stopped 2025-08-24 (68+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- HOSSACK CREEK DITCH (7800562) DWR↗ stopped 2025-08-24 (68+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BURKHARD DITCH (7800515) DWR↗ stopped 2025-08-06 (86+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- GRIMES DITCH (7800557) DWR↗ stopped 2025-08-06 (86+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- J C R DITCH (7800565) DWR↗ stopped 2025-08-03 (14+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- GALLEGOS HOME DITCH (7800552) DWR↗ stopped 2025-07-10 (12+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- BENNETT DITCH (7800509) DWR↗ stopped 2025-07-09 (114+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
- DYKE NO 1 DITCH (7800539) DWR↗ stopped 2025-06-27 (59+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
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 |
|---|---|---|---|
| PIEDRA RIVER MIN FLOW (7801903) DWR↗ | 1978-03-16 | 2.3% / 0.0% | 2.3% / 0.0% |
| PIEDRA RIVER MIN FLOW (7801910) DWR↗ | 1979-03-14 | 2.3% / 0.0% | 2.3% / 0.0% |
| PIEDRA RIVER MIN FLOW (7801902) DWR↗ | 1978-03-16 | 2.3% / 0.0% | 2.3% / 0.0% |
| PIEDRA RIVER MIN FLOW (7801901) DWR↗ | 1978-03-16 | 2.3% / 0.0% | 2.3% / 0.0% |
| LINN AND CLARK DITCH (7800578) DWR↗ | 1902-06-14 | 2.3% / 0.0% | 2.3% / 0.0% |
| PIEDRA RIVER MIN FLOW (7801900) DWR↗ | 1978-03-16 | 2.3% / 0.0% | 2.3% / 0.0% |
| LITTLE PAGOSA CREEK DIVR (7800659) DWR↗ | 1939-12-31 | 2.3% / 0.0% | 2.3% / 0.0% |
| PIEDRA FALLS DITCH (7800604) DWR↗ | 1934-07-18 | 2.3% / 0.0% | 2.3% / 0.0% |
| BARNES-MEUSER AND SHAW D (7800507) DWR↗ | 1903-12-31 | 2.3% / 0.0% | 2.3% / 0.0% |
| BUCKSKIN-NAILOR DITCH (7800513) DWR↗ | 1900-03-20 | 16.8% / 0.0% | 2.3% / 0.0% |
| PERKINS DITCH - STOLLSTEIMER CREEK (7800600) DWR↗ | 1963-07-28 | 2.3% / 0.0% | 2.3% / 0.0% |
| WEMINUCHE CR MIN FLOW (7801909) DWR↗ | 1978-03-16 | 2.3% / 0.0% | 2.3% / 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 ~1974 — idleness that begins before then may be unreported use, not nonuse (flagged † below).
- STEVENS SPRING (7800735) DWR↗ (1999-04-10, 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
- BUCY WATER LINE (7800514) DWR↗ (1963-07-07, 0.0 cfs decreed): last active 1970 — 55 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
- HERSCH DITCH (7800561) DWR↗ (1949-08-01, 8.0 cfs decreed): last active 1970 — 55 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
- MARTIN SPG D AND PL NO 1 (7800581) DWR↗ (1928-07-15, 1.0 cfs decreed): last active 1974 — 51 years idle
- PIEDRA STATION PIPE LINE (7800606) DWR↗ (1913-10-01, 0.1 cfs decreed): last active 1974 — 51 years idle
- SANDFORD WATERLINE (7800615) DWR↗ (1968-09-01, 0.0 cfs decreed): last active 1974 — 51 years idle
- YELLOW JACKET PIPE LINE (7800651) DWR↗ (1912-06-10, 0.1 cfs decreed): last active 1974 — 51 years idle
- LINN AND CLARK RESERVOIR (7803629) DWR↗ (1902-06-14, 0.0 cfs decreed): last active 1974 — 51 years idle
- J B MARTINEZ DITCH (7800564) DWR↗ (1883-06-14, 1.2 cfs decreed): last active 1975 — 50 years idle
- TRES PIEDRAS DITCH (7800639) DWR↗ (1943-10-01, 2.0 cfs decreed): last active 1975 — 50 years idle
Compliance screens (85 advisory flags)
Screened 118 of 371 structures with rights (139 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.
- PIEDRA FALLS DITCH (7800604) DWR↗: Observed p99 daily rate 26.1 cfs (max 33.0) exceeds total decreed absolute 26.0 cfs across 25808 recorded day(s).
- GORDON CREEK WETLANDS DIVERSION DITCH (7800756) DWR↗: Observed p99 daily rate 20.0 cfs (max 20.0) exceeds total decreed absolute 4.0 cfs across 1681 recorded day(s).
- FARROW AND PETERSON D (7800545) DWR↗: Observed p99 daily rate 18.4 cfs (max 23.3) exceeds total decreed absolute 16.6 cfs across 26551 recorded day(s).
- J B MARTINEZ DITCH (7800564) DWR↗: Observed p99 daily rate 17.0 cfs (max 20.0) exceeds total decreed absolute 1.2 cfs across 322 recorded day(s).
- CIMARRON DITCH (7800524) DWR↗: Observed p99 daily rate 15.0 cfs (max 15.0) exceeds total decreed absolute 5.0 cfs across 7748 recorded day(s).
- G S HATCHER DITCH (7800550) DWR↗: Observed p99 daily rate 15.0 cfs (max 16.8) exceeds total decreed absolute 7.5 cfs across 1550 recorded day(s).
- M E AND M DITCH (7800580) DWR↗: Observed p99 daily rate 14.4 cfs (max 21.0) exceeds total decreed absolute 12.0 cfs across 15526 recorded day(s).
- CLAYTON-REED DITCH (7800525) DWR↗: Observed p99 daily rate 13.0 cfs (max 13.1) exceeds total decreed absolute 10.0 cfs across 19001 recorded day(s).
- HOSSACK CREEK DITCH (7800562) DWR↗: Observed p99 daily rate 13.0 cfs (max 24.7) exceeds total decreed absolute 10.0 cfs across 10971 recorded day(s).
- J C R DITCH (7800565) DWR↗: Observed p99 daily rate 12.9 cfs (max 19.0) exceeds total decreed absolute 10.0 cfs across 6994 recorded day(s).
Seniority (top structures by decreed rate)
| Structure | Senior priority date | Rights | Decreed abs (cfs) | Decreed abs (AF) | Conditional? |
|---|---|---|---|---|---|
| PIEDRA RIVER MIN FLOW (7801903) DWR↗ | 1978-03-16 | 1 | 70.0 | 0 | — |
| PIEDRA RIVER MIN FLOW (7801910) DWR↗ | 1979-03-14 | 1 | 70.0 | 0 | — |
| PIEDRA RIVER MIN FLOW (7801902) DWR↗ | 1978-03-16 | 1 | 53.0 | 0 | — |
| PIEDRA RIVER MIN FLOW (7801901) DWR↗ | 1978-03-16 | 1 | 44.0 | 0 | — |
| LINN AND CLARK DITCH (7800578) DWR↗ | 1902-06-14 | 1 | 36.5 | 0 | — |
| PIEDRA RIVER MIN FLOW (7801900) DWR↗ | 1978-03-16 | 1 | 30.0 | 0 | — |
| PIEDRA FALLS DITCH (7800604) DWR↗ | 1934-07-18 | 2 | 26.0 | 0 | yes |
| LITTLE PAGOSA CREEK DIVR (7800659) DWR↗ | 1939-12-31 | 1 | 26.0 | 0 | — |
| BARNES-MEUSER AND SHAW D (7800507) DWR↗ | 1903-12-31 | 3 | 22.5 | 0 | — |
| BUCKSKIN-NAILOR DITCH (7800513) DWR↗ | 1900-03-20 | 7 | 21.9 | 0 | — |
| PERKINS DITCH - STOLLSTEIMER CREEK (7800600) DWR↗ | 1963-07-28 | 1 | 20.0 | 0 | — |
| ABRAHAM DAVIS DITCH (7800501) DWR↗ | 1900-04-01 | 4 | 18.0 | 0 | — |
| WEMINUCHE CR MIN FLOW (7801909) DWR↗ | 1978-03-16 | 1 | 18.0 | 0 | — |
| FARROW AND PETERSON D (7800545) DWR↗ | 1879-04-10 | 6 | 16.6 | 0 | — |
| F S MOCKLER IRR DITCH (7800544) DWR↗ | 1901-10-01 | 1 | 15.0 | 0 | — |
Recent inventory & legal-document changes
- 2026-10-01 — call released: 39556
- 2026-10-01 — call released: 37181
- 2026-09-30 — call released: 39596
- 2026-09-29 — call set: LA PLATA RIVER BASIN (39596)
- 2026-09-29 — call released: 38755
- 2026-09-26 — call released: 39564
- 2026-09-25 — call set: COTTONWOOD DITCH NO 2 (39564)
- 2026-09-25 — call released: 39537
Water-court filings this month (division-wide)
14 applications in the 2026-08 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 2026-10-31 (15 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 14 filings, with excerpts
| Case | What it asks | County | Excerpt |
|---|---|---|---|
09CW4
|
plan for augmentation | — | Case No. 09CW4. Applicant has installed parshall flumes, including one below the Lower Pond, and other measuring devices to administer the water rights that are the subject of this application and the related plan for augmentation. 4. Detailed outline of work … |
18CW3041
|
reasonable diligence | — | Case No. 18CW3041, for which Co-Applicants request entry of a finding of reasonable diligence: A. Dry Gulch Reservoir. i. Location: off-channel reservoir located on Dry Gulch, an ephemeral tributary to the San Juan River. The center point on the dam axis is lo… |
2026CW3018
|
— | LA PLATA | 2026CW3018 La Plata County, Water District No. 7 1. Name, address, and telephone number of applicant: South Durango Sanitation District, PO Box 2420, Durango, CO 81302, 970 -382-2623; Attorney: Floyd L. Smith, 48 CR 250, Suite 5, Durango, CO 81301; 2. Name of … |
2026CW3019
|
— | LA PLATA | 2026CW3019 La Plata County, Water District No. 7 1. Name, address, and telephone number of applicant: South Durango Sanitation District, PO Box 2420, Durango, CO 81302, 970-382- 2623; Attorney: Floyd L. Smith, 48 CR 250, Suite 5, Durango, CO 81301; 2. Name of … |
2026CW3020
|
new underground right | LA PLATA | 2026CW3020 La Plata County, 4M Ventures LLC (“Applicant”), c/o Trisha Mead, Managing Member, 213 Hottell Lane, Bayfield, Colorado 81122, Telephone: (970) 259-4346. APPLICATION FOR UNDERGROUND WATER RIGHT in LA PLATA COUNTY. Please send all pleadings and corres… |
2026CW3021
|
reasonable diligence | ARCHULETA | 2026CW3021 Archuleta County, (19CW3032) APPLICATION FOR FINDING OF REASONABLE DILIGENCE IN ARCHULETA COUNTY, COLORADO 1. Name and address of Applicant: Her Majesty’s Ranch, LLC Attention: Grant Gottfurcht, Member P.O. Box 3729 Pagosa Springs, CO 81147 (970) 73… |
2026CW3022
|
reasonable diligence | ARCHULETA | 2026CW3022 Archuleta County, Application for Finding of Reasonable Diligence. 1. Applicants: Pagosa Area Water and Sanitation District (“PAWSD”), P. O. Box 4610, Pagosa Springs, CO 81157, (970) 731-2691, and San Juan Water Conservancy District (“SJWCD”), P.O. … |
2026CW3023
|
— | MINERAL | 2026CW3023 Mineral County, (17CW3043, 10CW71, 98CW88)… |
2026CW3024
|
— | MINERAL | 2026CW3024 Mineral County, (17CW3050)… |
2026CW3025
|
reasonable diligence | MINERAL | 2026CW3025 (ref. 17CW3030, 73 -308D, et al.), MINERAL COUNTY AND ARCHULETA COUNTY, APPLICATION FOR FINDING OF REASONABLE DILIGENCE. Pagosa Area Water and Sanitation District (“PAWSD”), 100 Lyn Ave, Pagosa Springs, CO 81147, (970) 731 -2691; and San Juan Water … |
2026CW3026
|
reasonable diligence, make absolute | ARCHULETA | 2026CW3026 (ref. 17CW3014, 83CW145, et al.); ARCHULETA COUNTY; APPLICATION FOR FINDING OF REASONABLE DILIGENCE AND TO MAKE ABSOLUTE IN PART; Name, address, and telephone number of Applicant: Pagosa Area Water and Sanitation District (“District”) 100 Lyn Ave Pa… |
2026CW5
|
— | LA PLATA | 2026CW5 La Plata County, Matilda Reed and Jimmy Reed, 718 E 8 th Ave, Durango, CO 81301: Alolo Springs (Pipeline); Located in the NE 1/4 SE 1/4 of Section 29, T35N, R9W, NMPM, UTM coordinates: Easting 245440, Northing 4128618; An unnamed tributary of the Anima… |
2026CW6
|
— | SAN JUAN | 2026CW6 San Juan County, Seth Weber and Chelsea Weber, PO Box 461 Paonia, CO 81428: Wild Bunch (Pipeline); Date of Original Decree: 11/30/2007 Case No. 06CW127, Subsequent decrees: Date of Decree: 3/10/2016 Case No. 13CW3034, Date of Decree: 10/6/2022 Case No.… |
2026CW7
|
— | MONTEZUMA | 2026CW7 Montezuma County, Paul J. Bohmann and Mary M. Vozar, 5892 Road 38 Mancos, CO 81328 : Wilburm Tailwater Culvert (tailwater culvert); SE 1/4, NW1/4, Section 14, T35N, R14W, N.M.P.M., UTM Coordinates: Easting 37.297915, Northing -108.364547, Tailwater via… |
Water quality
The water itself, in this district
Four registers, each on its own schedule: what USGS sensors read right now, where samples have been taken, which stretches the state lists as impaired, and how the tap water of the systems here stands with EPA. None is a DWR record; each links its own page.
Right now
Source Provisional telemetry · fetched 2026-10-16 · verify at USGS current conditions ↗
No USGS continuous water-quality sensor reports from inside this district. Statewide sensors →
Where water has been sampled
Source Register of another agency · fetched 2026-10-08 · verify at Water Quality Portal ↗
The portal lists 830 sampling stations in this district's watersheds (Piedra 14080102; Upper San Juan 14080101, 3% of the district), of which 84 reported a sample in the last 5 years on the state and tribal side (USGS activity is in the station count, not in that figure). Most active: Southern Ute Tribe (41), Colorado Dept. of Public Health & Environment-WQCD (18), Mountain Studies Institute (MSI) (14). Most-sampled groups: Inorganics, Major, Metals, Physical, Nutrient, Inorganics, Minor, Non-metals. Every station as a file ↗
Results themselves are not fetched here; USGS samples added after March 2024 may not be in the portal's legacy profiles yet.
Drinking water
Source Register of another agency · fetched 2026-10-07 · verify at EPA SDWIS ↗
2 community systems touch this district. None carries an open health-based violation on EPA's record. EPA sampled 1 of them for PFAS in 2023–25; none had PFOA or PFOS at or above the 2024 limit.
| System | Serves | EPA record | PFAS (UCMR 5) | Lead, latest 90th pct |
|---|---|---|---|---|
| PAGOSA AREA WSD | 11,069 | clean, last 12 quarters | none detected | 0.0024 mg/L |
| ASPEN SPRINGS MD | 290 | clean, last 12 quarters | not sampled | — |
EPA's record carries violations and lead/copper percentiles; nitrate and disinfection by-product results are not in it. UCMR 5 samples are monitoring, not compliance, and the 2024 PFOA/PFOS limits equal its reporting limit, so any detection of those two is at or above them.
Impaired waters
Source Register of another agency · verify at EPA ATTAINS ↗
The state's 303(d) impaired-waters list has not been joined to this basin's own watershed boundary yet, so nothing is shown rather than a guess; the basins with a join carry the full list here. Why the join is geometry, not a name match.
Call cascade
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.
This week's diagnostic
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System status
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Active river calls
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Hydrographs vs. historical envelope
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Anomaly flags
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Snowpack — no snow on the ground at 1 SNOTEL site — normal for the date; the snow year begins in October and typically peaks around March 28. Runoff outlook — Piedra R nr Arboles: even odds of at least 14 kAF over 06-01 to 07-31 — 24% 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) | Median (in) | % of median | Typical peak |
|---|---|---|---|---|---|
| Weminuche Creek | 10730 | 0.0 | 0.0 | — | March 28 (16.4 in) |
Piedra R nr Arboles — 06-01 to 07-31 volume, thousand acre-feet (chance the volume is AT LEAST this):
| 90% | 70% | 50% | 30% | 10% | Normal |
|---|---|---|---|---|---|
| 6 | 10 | 14 | 25 | 40 | 58 |
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: 4 parent disagreements, 2 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, 5 agree. Know this water? Tell us →
| Stream | This site routes it to | DWR routes it to |
|---|---|---|
| Yellowjacket Creek | the mainstem | Piedra River |
| Devil Creek | the mainstem | Piedra River |
| Dutton Creek | the mainstem | Martinez Creek |
| Ignacio Creek | the mainstem | Piedra River |
Sizable streams DWR maps here that this network does not carry:
Martinez Creek (16 mi) · Archuleta Creek (6 mi)