La Plata River Basin

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 17 ranked gages are running at a median 77% of their own long-term norm for this window — 9 below a typical year, 8 at or above. Driest relative to its record: ENTERPRISE DITCH AT THE COLORADO-NEW MEXICO STATELINE, ranking 1st lowest of 36 years.

Gage flow trend & changepoints

Of the 25 gages with enough record, 8 are trending down and 0 up, and 7 carry a detected shift. The clearest is Long Hollow at the Mouth near Red Mesa, its annual mean flow changing -2.06 cfs per decade (-43.5% of its median annual flow) over 32 years (p<0.0001). The other 16 show no clear signal either way.

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

⚠️ 1 gage flagged: their records may have quietly shifted against their neighbours, so treat their trends with caution.

16 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. 23 gage(s) and 47 structure(s) report in 2026, but structure reporting only reached half its modern level around ~1968. 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: 16% of 464 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 (971 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.

• LA PLATA RIVER AT HESPERUS, CO: reach shifted from +57 cfs to +0 cfs summer mean (more losing, p=0.000, 41 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
• LONG HOLLOW AT THE MOUTH NEAR RED MESA: reach shifted from +0 cfs to -28 cfs summer mean (more losing, p=0.024, 22 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]
• LA PLATA RIVER AT THE COLORADO-NEW MEXICO STATELINE: reach shifted from -19 cfs to +36 cfs summer mean (more gaining, p=0.002, 75 yr) [alluvial valley: real alluvial aquifer -- a decades-long shift toward losing is the classic signature of alluvial pumping and urbanization]

Groundwater now has its own tab: 49 monitored well(s), water-table trends, stream corridors, and the advisory depletion screen.

Reservoirs now has its own tab: 9 reservoir(s), end-of-year storage back to 1950, click-to-chart histories.

Cross-gage pattern fingerprint

Over the 38-year window with full coverage (1989–2026), the dominant shared pattern across 3 gage(s) explains 85% 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.

• R- 102 (diversion): -0.2 cfs (3% of that reach's correction)
• CCC DITCH (diversion): -0.2 cfs (3% of that reach's correction)
• R-1813 (diversion): -0.2 cfs (3% of that reach's correction)
• R-1815 (diversion): -0.2 cfs (3% of that reach's correction)
• R-1816 (diversion): -0.2 cfs (3% of that reach's correction)
• R-1809 (diversion): -0.2 cfs (3% of that reach's correction)
• R-1814 (diversion): -0.2 cfs (3% of that reach's correction)
• HUNTINGTON SPRING (return): -0.2 cfs (3% of that reach's correction)
• STEEL DRAW PUMP AND PL (diversion): -0.2 cfs (3% of that reach's correction)
• D- 402 (diversion): -0.2 cfs (3% of that reach's correction)

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

94 water-level measurements across 49 monitored well(s) — 30 alluvial, 0 bedrock — plus 0 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 0 well(s) with enough record for a trend test: 0 declining, 0 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.

LA PLATA RIVER AT HESPERUS, CO: 4 alluvial well(s) nearby

LA PLATA RIVER AT THE COLORADO-NEW MEXICO STATELINE: 1 alluvial well(s) nearby

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 ↗

9 reservoir(s) with 600 storage measurement(s), 1950–2011. Basin storage as of 2010-10-31 (the record's own end — reservoir records publish ~annually): 358 AF across 2 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 2026-10-18 · 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 1 of 1 sites (0.8 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 (1995–2026)

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 32 winters the snow never came — the pack peaked below 80% of its median. In 2 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: 2002, 2013, 2015, 2018, 2021, 2025, 2026. The snow left early: 1996, 2022.

Computed by this site from 1 SNOTEL site’ full daily records (NRCS AWDB, back to 1995). 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 — La Plata R at Hesperus

NRCS's final issue (2026-06-01) calls it even odds that at least 2 kAF arrives over 06-01 to 07-31 — 27% of a normal season; almost certainly at least 1, probably not more than 4. Our own record at this gage shows 2 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 65 replayed seasons (18% typical miss unadjusted vs 18% 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 19%, with a high bias of 4%, 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 (1995–2026)

Across 32 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 56% 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 1.5). In warm, early-melt years the river delivered a median of 58% of a normal season, against 94% 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 2026-10-13 · verify at U.S. Drought Monitor ↗

Right now

This is the 105th-driest week 39 in 109 years of record at LA PLATA RIVER AT HESPERUS, CO (as of 2026-09-21; this week’s flow sits at the 96th 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, La Plata County is 6% in D2 severe drought (2026-10-13). The law agrees: the most senior active call leaves 0% of this district’s decreed flow rights junior to the calling right this week.

Every year since 1917, week by week

Each thin row is a year at LA PLATA RIVER AT HESPERUS, 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 39 weeks recorded so far, 2026’s weekly trace most resembles 1972 (mean gap 12.8 percentile points; next closest 2014 (20.3), 1934 (23.2)). 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 La Plata county — 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 2008 — 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 (766 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 1994, federal crop insurance has paid $689,401 in drought-caused claims across La Plata county — 18.3% of all insured crop losses there. The worst year was 2002 ($75,597).

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 (174 rights across 110 years of shared record), colored by that year’s wetness from the barcode above. Here the correlation is +0.17 — 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 ↗

2 systems touch this district (2 community systems reporting 508 people served, a figure that counts a wholesaler's customers twice); none carries an open health-based violation on EPA's record.

Instream-flow rights held by the state

Source Register of another agency · fetched 2026-10-18 · verify at CWCB instream flow program ↗

6 reaches over 22.8 miles, held by the Colorado Water Conservation Board so that water stays in the stream. Every reach, with its schedule and case →

• La Plata River, 13.8 mi: 9 (4/1 - 10/31), 5 (11/1 - 3/31) cfs (appropriated 1984, 84CW0270) · dossier
• Basin Creek, 2.0 mi: 4 (1/1 - 12/31) cfs (appropriated 1976, 76W1497) · dossier
• Columbus Creek, 2.0 mi: 3 (1/1 - 12/31) cfs (appropriated 1976, 76W1495) · dossier
• Lewis Creek, 2.0 mi: 2 (1/1 - 12/31) cfs (appropriated 1976, 76W1494) · dossier
• Madden Creek, 2.0 mi: 1 (1/1 - 12/31) cfs (appropriated 1976, 76W1490) · dossier
• Tirbircio Creek, 1.0 mi: 2 (1/1 - 12/31) cfs (appropriated 1976, 76W1492) · dossier

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 2020-05-31. Of the 20 structures with a yield estimate, the median one’s senior right was in priority 23% of a median irrigation season and 0% in a dry one. 25 abandonment screens and 30 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: 447 across 364 structure(s); 83 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.

Why diversions stopped — call-based explanations

Sustained diversion stops matched to senior administrative calls.

• LA PLATA IRG DITCH (3300501) DWR↗☆ stopped 2025-08-13 (11+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• WHITE-ROUX AND OWENS D (3300539) DWR↗☆ stopped 2025-08-12 (43+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• H H DITCH (3300536) DWR↗☆ stopped 2025-07-19 (82+ days) — call at CONLEY DITCH curtailing 100% of its decreed rate [heuristic-strong]
• WARREN-VOSBURGH DITCH (3300550) DWR↗☆ stopped 2025-07-14 (91+ days) — call at CONLEY DITCH curtailing 100% of its decreed rate [heuristic-strong]
• BIG STICK DITCH (3300554) DWR↗☆ stopped 2025-07-07 (94+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• HAY GULCH DITCH (3300504) DWR↗☆ stopped 2025-06-27 (15+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• LA PLATA IRG DITCH (3300501) DWR↗☆ stopped 2025-06-26 (17+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• KELLER DITCH (3300515) DWR↗☆ stopped 2025-06-25 (18+ days) — call at LA PLATA RIVER BASIN curtailing 100% of its decreed rate [heuristic-strong]
• NEW SPONSEL DITCH (3300506) DWR↗☆ stopped 2025-06-22 (9+ days) — call at LA PLATA RIVER BASIN curtailing 100% of its decreed rate [heuristic-strong]
• ENTERPRISE ENLARGEMENT D (3300540) DWR↗☆ stopped 2025-06-22 (7+ days) — call at LA PLATA RIVER BASIN curtailing 100% of its decreed rate [heuristic-strong]
• LA PLATA R & CHERRY CR D (3300508) DWR↗☆ stopped 2025-06-20 (112+ days) — call at HENRY BOLEN DITCH curtailing 100% of its decreed rate [heuristic-strong]
• MCCALEB DITCH (3300502) DWR↗☆ stopped 2025-06-19 (126+ 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.

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 ~1968 — idleness that begins before then may be unreported use, not nonuse (flagged † below).

• WELBORN-SENA DITCH (3300573) DWR↗☆ (1915-05-27, 0.5 cfs decreed): last active 1968 — 57 years idle
• WILLOW CREEK DITCH (3300521) DWR↗☆ (1882-08-15, 0.5 cfs decreed): last active 1970 — 55 years idle
• HUBBS DITCH NO 2 (3300580) DWR↗☆ (1923-06-01, 2.0 cfs decreed): last active 1970 — 55 years idle
• HUBBS NO 3 DITCH (3300581) DWR↗☆ (1923-07-01, 1.0 cfs decreed): last active 1970 — 55 years idle
• MCGUIRE DITCH (3300524) DWR↗☆ (1887-07-01, 1.0 cfs decreed): last active 1980 — 45 years idle
• WALKER DITCH (3300584) DWR↗☆ (1932-12-31, 1.0 cfs decreed): last active 1980 — 45 years idle
• GREER DITCH (3300626) DWR↗☆ (1910-12-31, 0.8 cfs decreed): last active 1980 — 45 years idle
• NARANJO DITCH (3300537) DWR↗☆ (1899-06-10, 1.3 cfs decreed): last active 1982 — 43 years idle
• ENO SEEPAGE DITCH (3300570) DWR↗☆ (1912-06-17, 2.0 cfs decreed): last active 1984 — 41 years idle
• ISGAR IRRIGATION SYSTEM (3300616) DWR↗☆ (1925-12-31, 3.0 cfs decreed): last active 1985 — 40 years idle

Compliance screens (30 advisory flags)

Screened 64 of 364 structures with rights (71 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.

• TOWNSITE DITCH (3300551) DWR↗☆: Observed p99 daily rate 20.0 cfs (max 30.3) exceeds total decreed absolute 15.5 cfs across 19866 recorded day(s).
• CAVINESS DITCH (3300505) DWR↗☆: Observed p99 daily rate 9.1 cfs (max 16.6) exceeds total decreed absolute 4.0 cfs across 7987 recorded day(s).
• SPONSEL AND MYERS DITCH (3300514) DWR↗☆: Observed p99 daily rate 9.0 cfs (max 13.0) exceeds total decreed absolute 2.0 cfs across 7669 recorded day(s).
• GH DITCH (3300669) DWR↗☆: Observed p99 daily rate 7.0 cfs (max 7.0) exceeds total decreed absolute 0.5 cfs across 2048 recorded day(s).
• AMMONS DITCH (3300518) DWR↗☆: Observed p99 daily rate 6.7 cfs (max 108.0) exceeds total decreed absolute 6.0 cfs across 26144 recorded day(s).
• ENTERPRISE ENLARGEMENT D (3300540) DWR↗☆: Observed p99 daily rate 5.4 cfs (max 11.0) exceeds total decreed absolute 2.6 cfs across 43455 recorded day(s).
• NEW SPONSEL DITCH (3300506) DWR↗☆: Observed p99 daily rate 4.9 cfs (max 8.0) exceeds total decreed absolute 2.5 cfs across 9920 recorded day(s).
• UPPER DAVIS DITCH (3300541) DWR↗☆: Observed p99 daily rate 4.5 cfs (max 4.5) exceeds total decreed absolute 1.0 cfs across 3606 recorded day(s).
• WHITE-ROUX AND OWENS D (3300539) DWR↗☆: Observed p99 daily rate 3.5 cfs (max 12.0) exceeds total decreed absolute 1.0 cfs across 11421 recorded day(s).
• MORGAN AND STAMBAUGH D (3300546) DWR↗☆: Observed p99 daily rate 3.5 cfs (max 4.2) exceeds total decreed absolute 2.5 cfs across 9079 recorded day(s).

Seniority (top structures by decreed rate)

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)

4 applications in the 2026-09 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 2026-11-30 (43 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.

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 2026-10-18 · 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 150 sampling stations in this district's watershed (Middle San Juan 14080105), of which 9 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 River Watch (5), Southern Ute Tribe (3), Colorado Dept. of Public Health & Environment-WQCD (1). Most-sampled groups: Inorganics, Major, Metals, Physical, Inorganics, Minor, Non-metals, 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 ↗

2 community systems touch this district. None carries an open health-based violation on EPA's record. EPA sampled 0 of them for PFAS in 2023–25.

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.