Rio Grande

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 60 ranked gages are running at a median 100% of their own long-term norm for this window — 26 below a typical year, 34 at or above. Driest relative to its record: BASSI NORTH FARM ROAD GRAVEL PIT, ranking 1st lowest of 2 years.

Gage flow trend & changepoints

Of the 98 gages with enough record, 10 are trending down and 0 up, and 14 carry a detected shift. The clearest is Closed Basin Project Canal near Alamosa, its annual mean flow changing -6.03 cfs per decade (-27.9% of its median annual flow) over 37 years (p<0.0001). The other 80 show no clear signal either way. 4 transbasin gages meter imported or exported water — marked ⇆ below and kept out of these counts, because that flow is an operator's decision, not the basin's hydrology (all transbasin diversions).

Drought history, cost, and the four-century context moved to the Drought tab.

⚠️ 7 gages flagged: their records may have quietly shifted against their neighbours, so treat their trends with caution.

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

2 of those show a significant trend once extended backwards from a retired neighbour's record: Rio Grande below Taos Junction Bridge near Taos, Nm (127 yr, decreasing); Rio Grande at Wagon Wheel Gap (118 yr, decreasing, suspect). Those are reconstructions, not measurements — each gage's page shows both.

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. 73 gage(s) and 311 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1957. 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 †.

Mass-balance (network closure) trend

Structure divrec-history backfill coverage as of the last check: 9% of 2958 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 (1950–2026)

Mass-balance kinks computed for every summer month back to 1950 (4600 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.

• RIO GRANDE AT MONTE VISTA: reach shifted from -934 cfs to +377 cfs summer mean (more gaining, p=0.000, 77 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=0.64) -- part of it may be unaccounted water becoming accounted, not hydrologic change] [3 alluvial wells within 2 mi of the gage; pooled water table -1.4 ft (1946–1975, no_trend)]
• PRAIRIE DITCH NEAR SEVEN-MILE PLAZA: reach shifted from -239 cfs to -91 cfs summer mean (more gaining, p=0.004, 17 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records] [4 alluvial wells within 2 mi of the gage; pooled water table -5.6 ft (1947–2005, no_trend)]
• RIO GRANDE AT ALAMOSA: reach shifted from -291 cfs to +194 cfs summer mean (more gaining, p=0.002, 77 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=0.62) -- part of it may be unaccounted water becoming accounted, not hydrologic change] [2 alluvial wells within 2 mi of the gage; pooled water table +1.2 ft (1949–2021, increasing)]
• PINOS CREEK NEAR DEL NORTE, CO.: reach shifted from -369 cfs to +30 cfs summer mean (more gaining, p=0.000, 77 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=0.63) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• RIO GRANDE ABOVE TRINCHERA CREEK NEAR LA SAUSES: reach shifted from +43 cfs to +206 cfs summer mean (more gaining, p=0.003, 77 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=0.66) -- part of it may be unaccounted water becoming accounted, not hydrologic change]
• BEAVER CREEK BELOW BEAVER CREEK RESERVOIR: reach shifted from -70 cfs to -40 cfs summer mean (more gaining, p=0.009, 29 yr) [sedimentary uplands: moderate groundwater connectivity -- gain/loss shifts can be real aquifer response; corroborate with nearby well records]

Groundwater now has its own tab: 605 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 66 reservoir(s), end-of-year storage back to 1975, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 115-year window with full coverage (1912–2026), the dominant shared pattern across 3 gage(s) explains 94% 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.

Structures most implicated by reconciliation (as of 2026-09-27)

Which structures' data absorbed the most correction when the current mass-balance snapshot was reconciled -- see the Historical tab for the full picture on any date.

• SONDLES D (diversion): -33.0 cfs (25% of that reach's correction)
• HEILMAN SLOUGH D (diversion): -33.0 cfs (25% of that reach's correction)
• BLANCA CNL (diversion): -33.0 cfs (25% of that reach's correction)
• KENILWORTH CNL (diversion): -33.0 cfs (25% of that reach's correction)
• ORR WASTE D (diversion): +22.0 cfs (6% of that reach's correction)
• EHROWITZ D (diversion): +22.0 cfs (6% of that reach's correction)
• WILLOW ROAD SPRING (return): +22.0 cfs (6% of that reach's correction)
• WILLOW SPRING (return): +22.0 cfs (6% of that reach's correction)
• UPPER HORSE CANYON SPR (return): +22.0 cfs (6% of that reach's correction)
• LOG CANYON SPRING (return): +22.0 cfs (6% of that reach's correction)

Source DWR administrative record · verify at DWR groundwater wells ↗ Source DWR administrative record · verify at DWR well permits ↗

52,552 water-level measurements across 605 monitored well(s) — 350 alluvial, 117 bedrock — plus 2 administered well(s) reporting metered pumping.

Well map

3D aquifer x-ray

Every aquifer unit as its own head surface, animated through time.

Water-table trends

Of 149 well(s) with enough record for a trend test: 95 declining, 7 rising.

Stream corridors — the surface connection

Where a reach's gain or loss has shifted, the wells within two miles of its anchoring gage and what their water table did over the same era.

RIO GRANDE AT MONTE VISTA: 3 alluvial well(s) nearby; pooled water table -1.4 ft (1946–1975, no_trend, p=0.2643). Glover screen: 0.4 cfs of nearby metered alluvial pumping → est. lagged depletion 0.2–0.3 cfs (uncalibrated T/S ranges; flagged for SPDSS calibration, AWAS cross-check, and expert review — DWR's AWAS is the authority).

PRAIRIE DITCH NEAR SEVEN-MILE PLAZA: 4 alluvial well(s) nearby; pooled water table -5.6 ft (1947–2005, no_trend, p=0.0892)

RIO GRANDE AT ALAMOSA: 2 alluvial well(s) nearby; pooled water table +1.2 ft (1949–2021, increasing, p=0.0)

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.

Source DWR administrative record · verify at DWR structure records ↗

66 reservoir(s) with 27,950 storage measurement(s), 1975–2026. Basin storage as of 2025-10-31 (the record's own end — reservoir records publish ~annually): 48,114 AF across 16 reservoir(s).

Reservoir map — how full is each vessel?

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.

Source Independent agency measurement · fetched 2026-10-14 · verify at NRCS report generator ↗ Source Our computation, scored against a reference · NRCS forecast, graded here against the gage record

Snow-water equivalent, WY2027

A trace of snow at 5 of 5 sites (2.2 in of water at most); the median for the date is zero, so there is no percent to show yet. 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.

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 (1981–2026)

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 7 of the last 46 winters the snow never came — the pack peaked below 80% of its median. In 3 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: 1988, 1996, 2002, 2003, 2018, 2025, 2026. The snow left early: 2006, 2012, 2022.

Computed by this site from 5 SNOTEL sites’ full daily records (NRCS AWDB, back to 1981). 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 — Rio Grande at Thirty Mile Bridge

NRCS's final issue (2026-06-01) calls it even odds that at least 19 kAF arrives over 06-01 to 09-30 — 26% of a normal season; almost certainly at least 10, probably not more than 43. Our own record at this gage shows 22 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 81 replayed seasons (13% typical miss unadjusted vs 16% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

How good are these forecasts here? (1962–2025)

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 14%, with a low bias of 4%, and the observed volume landed inside the stated 10–90% band 84% 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 (1981–2026)

Across 46 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 84% 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 0.6). In warm, early-melt years the river delivered a median of 70% of a normal season, against 108% 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.

Runoff outlook — Rio Grande at Wagon Wheel Gap

NRCS's final issue (2026-06-01) calls it even odds that at least 45 kAF arrives over 06-01 to 09-30 — 25% of a normal season; almost certainly at least 22, probably not more than 81. Our own record at this gage shows 54 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 41 replayed seasons (12% typical miss unadjusted vs 17% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

How good are these forecasts here? (1982–2025)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 42 seasons: the median miss of the 50% forecast is 12%, with a low bias of 6%, and the observed volume landed inside the stated 10–90% band 81% 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 (1981–2026)

Across 46 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 84% 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 76% of a normal season, against 116% 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.

Runoff outlook — SF Rio Grande at South Fork

NRCS's final issue (2026-06-01) calls it even odds that at least 17 kAF arrives over 06-01 to 09-30 — 35% of a normal season; almost certainly at least 8, probably not more than 29. Our own record at this gage shows 15 kAF actually delivered. New forecasts begin in January. How to read these numbers →

The record-adjusted April benchmark

NRCS’s April issue (2026-04-01) called even odds at 31 kAF over 04-01 to 09-30. Re-anchoring that number on this river’s own history — how its April issues have verified, the winter’s baseflow, and the district’s April 1 snowpack — moves it to 34 kAF. The river delivered 50 kAF.

Computed by this site — not an NRCS number, and shown only because it earned it: replayed over 62 past seasons here (1962–2025), never seeing the year it predicts, the adjustment cut the typical April miss from 14% to 13%. At points where it does not beat NRCS, no adjusted number appears. Coefficients are frozen each August; the model never changes mid-season. Method and honest limits →

How good are these forecasts here? (1950–2025)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 74 seasons: the median miss of the 50% forecast is 16%, with a low bias of 0%, and the observed volume landed inside the stated 10–90% band 90% 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 (1981–2026)

Across 46 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 1.0). In warm, early-melt years the river delivered a median of 75% of a normal season, against 110% 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.

Runoff outlook — Rio Grande nr Del Norte

NRCS's final issue (2026-06-01) calls it even odds that at least 65 kAF arrives over 06-01 to 09-30 — 25% of a normal season; almost certainly at least 25, probably not more than 117. Our own record at this gage shows 68 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 63 replayed seasons (12% typical miss unadjusted vs 13% adjusted), so none is shown — NRCS’s own forecast, unadjusted, is the best April benchmark available for this river. Why we test →

How good are these forecasts here? (1950–2025)

Grading every April issue against what the river then delivered, measured at this gage’s own record — 75 seasons: the median miss of the 50% forecast is 13%, with a low bias of 2%, and the observed volume landed inside the stated 10–90% band 84% 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 (1981–2026)

Across 46 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 0.9). In warm, early-melt years the river delivered a median of 64% of a normal season, against 108% 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.

Source Our computation, no independent reference · computed here from the screened DWR record Source Independent agency measurement · fetched 2026-10-06 · verify at U.S. Drought Monitor ↗

Right now

This is the 6th-driest week 39 in 129 years of record at RIO GRANDE AT EMBUDO, NM. (as of 2026-09-21; this week’s flow sits at the 4th 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, Mineral County is 34% in D3 extreme drought (2026-10-06). 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 1889, week by week

Each thin row is a year at RIO GRANDE AT EMBUDO, NM.; 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 39 weeks recorded so far, 2026’s weekly trace most resembles 2002 (mean gap 6.2 percentile points; next closest 2018 (7.4), 1956 (10.7)). 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 Alamosa, Conejos, Costilla, Elbert, Hinsdale, La Plata, Mineral, Rio Grande, Saguache 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 1968 — 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 (3235 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

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.

What drought has cost here

Since 1991, federal crop insurance has paid $19,952,790 in drought-caused claims across Alamosa, Conejos, Costilla, Elbert, Hinsdale, La Plata, Mineral, Rio Grande, Saguache counties — 6.3% of all insured crop losses there. The worst year was 2012 ($2,373,752).

USDA crop-insurance indemnities where the recorded cause of loss is drought, summed over the counties this district's gages sit in. Counties overlap water districts imperfectly, and insured-crop claims are a floor on drought damage, not a total. Source: USDA RMA cause-of-loss files.

When this basin claimed its water

Every bar is a year’s new appropriations (8,123 rights across 131 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.

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 ↗

11 systems touch this district (11 community systems reporting 24,405 people served, a figure that counts a wholesaler's customers twice); 1 of them carries an open health-based violation on EPA's record.

and 3 more; the full directory filters by district.

Instream-flow rights held by the state

Source Register of another agency · fetched 2026-10-11 · verify at CWCB instream flow program ↗

78 reaches over 523.1 miles and 13 natural lake levels, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →

• Rio Grande, 21.2 mi: 65 (10/1 - 4/30), 150 (5/1 - 9/30) cfs (appropriated 1982, 83CW0039) · dossier
• Goose Creek, 18.5 mi: 8 (10/1 - 4/30), 15 (5/1 - 9/30) cfs (appropriated 1982, 83CW0038) · dossier
• Park Creek, 15.1 mi: 6 (10/1 - 4/30), 8 (5/1 - 9/30) cfs (appropriated 1980, 80CW0091) · dossier
• Embargo Creek, 15.0 mi: 5 (1/1 - 12/31) cfs (appropriated 1976, 76W3647) · dossier
• Rio Grande, 14.4 mi: 80 (10/1 - 4/30), 160 (5/1 - 9/30) cfs (appropriated 1982, 83CW0042) · dossier
• Beaver Creek, 14.3 mi: 8 (10/1 - 4/30), 14 (5/1 - 9/30) cfs (appropriated 1980, 80CW0095) · dossier

and 85 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 1850-12-31 to 2015-09-24. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 6% of a median irrigation season and 0% in a dry one. 16 abandonment screens and 184 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: 9243 across 8023 structure(s); 338 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 1969–2025, administration on this district has been tightening: 3 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.

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

• BAUER D (2000528) DWR↗☆ stopped 2025-10-22 (5+ days) — call at SANGRE CRISTO TRINCHERA curtailing 100% of its decreed rate [heuristic-strong]
• CADLE D 3 (2000559) DWR↗☆ stopped 2025-09-07 (35+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• BILLINGS D (2000546) DWR↗☆ stopped 2025-08-29 (7+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 96% of its decreed rate [heuristic-partial]
• BREY D (2000552) DWR↗☆ stopped 2025-08-28 (44+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• CADLE D 1 (2000557) DWR↗☆ stopped 2025-08-17 (56+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• BUTLER IRR D (2000556) DWR↗☆ stopped 2025-08-11 (7+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• BELLOWS CR D 1 (2000531) DWR↗☆ stopped 2025-07-28 (21+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• BAUER D (2000528) DWR↗☆ stopped 2025-07-27 (5+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 100% of its decreed rate [heuristic-strong]
• BARCLAY D (2000524) DWR↗☆ stopped 2025-07-14 (106+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 75% of its decreed rate [heuristic-partial]
• BREENE MYERS D (2000551) DWR↗☆ stopped 2025-06-30 (110+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 57% of its decreed rate [heuristic-partial]
• BEVAN D 4 (2000541) DWR↗☆ stopped 2025-06-19 (116+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 56% of its decreed rate [heuristic-partial]
• BENNETT CR D (2000535) DWR↗☆ stopped 2025-06-18 (29+ days) — call at RIO GRANDE COMPACT - LOBATOS curtailing 80% of its decreed rate [heuristic-partial]

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.

Abandonment radar (16 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 ~1957 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• EAGLE D (2000613) DWR↗☆ (1875-05-05, 5.3 cfs decreed): last active 1962 — 34 years idle
• LOHR OVERFLOW SEPG D #1 (2000718) DWR↗☆ (1897-06-28, 9.0 cfs decreed): last active 1962 — 34 years idle
• WINTZ D (2000908) DWR↗☆ (1910-10-14, 2.1 cfs decreed): last active 1962 — 34 years idle
• MEADOW LAKE RES (2003547) DWR↗☆ (1916-06-01, 0.0 cfs decreed): last active 1965 — 31 years idle
• LARICK D 5 (2000708) DWR↗☆ (1874-05-01, 2.0 cfs decreed): last active 1966 — 30 years idle
• MACLEOD D 2 (2000724) DWR↗☆ (1882-05-31, 1.0 cfs decreed): last active 1970 — 26 years idle
• MACLEOD D 5 (2000727) DWR↗☆ (1878-04-01, 1.0 cfs decreed): last active 1970 — 26 years idle
• SHERIDAN NORTH D (2000841) DWR↗☆ (1883-04-01, 2.0 cfs decreed): last active 1970 — 26 years idle
• SHERIDAN SOUTH D (2000842) DWR↗☆ (1882-09-30, 3.0 cfs decreed): last active 1970 — 26 years idle
• BOWEN DRAIN DIST LAT SYS (2000549) DWR↗☆ (1922-06-21, 53.5 cfs decreed): last active 1974 — 22 years idle

Compliance screens (184 advisory flags)

Screened 342 of 8023 structures with rights (413 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.

• EMPIRE CNL (2000623) DWR↗☆: Observed p99 daily rate 516.0 cfs (max 613.0) exceeds total decreed absolute 505.9 cfs across 49601 recorded day(s).
• RIO GRANDE RES (2003554) DWR↗☆: Observed p99 daily rate 224.0 cfs (max 2039.3) exceeds total decreed absolute 3.7 cfs across 250131 recorded day(s).
• PRAIRIE DRAIN D (2000799) DWR↗☆: Observed p99 daily rate 188.0 cfs (max 216.0) exceeds total decreed absolute 40.0 cfs across 2199 recorded day(s).
• COSTILLA D (2000587) DWR↗☆: Observed p99 daily rate 134.0 cfs (max 191.0) exceeds total decreed absolute 103.3 cfs across 28368 recorded day(s).
• SANTA MARIA RES (2003558) DWR↗☆: Observed p99 daily rate 109.4 cfs (max 1696.0) exceeds total decreed absolute 3.7 cfs across 146061 recorded day(s).
• EXCELSIOR D (2000627) DWR↗☆: Observed p99 daily rate 106.0 cfs (max 154.0) exceeds total decreed absolute 89.7 cfs across 40685 recorded day(s).
• CENTENNIAL D (2000566) DWR↗☆: Observed p99 daily rate 97.0 cfs (max 132.0) exceeds total decreed absolute 82.4 cfs across 35085 recorded day(s).
• CONTINENTAL RES (2003536) DWR↗☆: Observed p99 daily rate 95.3 cfs (max 1647.6) exceeds total decreed absolute 3.7 cfs across 162004 recorded day(s).
• CHICAGO D (2000575) DWR↗☆: Observed p99 daily rate 85.0 cfs (max 196.0) exceeds total decreed absolute 66.4 cfs across 33392 recorded day(s).
• WESTSIDE D (2000903) DWR↗☆: Observed p99 daily rate 50.0 cfs (max 80.0) exceeds total decreed absolute 35.8 cfs across 22621 recorded day(s).

Seniority (top structures by decreed rate)

Recent inventory & legal-document changes

• 2026-10-08 — call set: CHICAGO D (39692)
• 2026-10-08 — call released: 39674
• 2026-10-08 — call set: VALDEZ D (39691)
• 2026-10-08 — call released: 39668
• 2026-10-05 — call set: CHICAGO D (39674)
• 2026-10-05 — call released: 39667
• 2026-10-05 — call set: NEWTON D 2 (39673)
• 2026-10-05 — call released: 39639

Water-court filings this month (division-wide)

2 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 (17 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.

Active substitute water supply plans in this district

Temporary State Engineer approvals to divert out of priority (37-92-308 / 37-90-137). A structure operating under one behaves differently under a call than its decreed rights alone suggest — the priority tables above don't know about these; this list does. Source: DWR’s active-SWSP register, refreshed nightly.

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 2026-10-14 · 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 2,728 sampling stations in this district's watersheds (Rio Grande Headwaters 13010001, 55% of the district; Alamosa-Trinchera 13010002, 28% of the district; San Luis 13010003, 15% of the district; Saguache 13010004, 3% of the district), of which 107 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: Colorado Dept. of Public Health & Environment-WQCD (79), Colorado River Watch (25), USGS Colorado Water Science Center (3). Most-sampled groups: Inorganics, Major, Metals, Physical, Nutrient, Inorganics, Minor, 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 ↗

11 community systems touch this district. 1 carries an open health-based violation on EPA's record. EPA sampled 3 of them for PFAS in 2023–25; none had PFOA or PFOS at or above the 2024 limit.

and 1 more; the full directory filters by district.

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.