Nevada reservoir · state assessment record

Squaw Creek Reservoir

Assessment decisions reported by Nevada to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.

46
Assessed acres
Reservoir
Water type
View watchlist

This waterbody in one line

Squaw Creek Reservoir, a reservoir in Nevada, is assessed as not supporting one or more designated uses, with 3 listed impairment causes in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits above the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (3 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.

Not Supporting
overall status
P53
Assessed size nationally
P5
Shorter cause list
Not Supporting
aquatic life

Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.

F
Water Quality Standing
33/100
Squaw Creek Reservoir

A composite of this record's EPA ATTAINS designated-use verdicts, filed impairment count, and assessment currency, weighted and benchmarked against the national corpus of assessed active waterbodies. This is a water-quality standing, not a human-recreation or property-value judgment, and dimensions with no filed verdict drop out rather than count against the score.

RecreationF
Not supporting
Swimming, boating, and other primary/secondary contact recreation
Drinking WaterA+
Meeting criteria
Suitability as a public drinking-water source
Aquatic LifeF
Not supporting
Support for fish, invertebrates, and other aquatic organisms
Fish ConsumptionN/A
Not assessed
Safety of eating fish caught in this water
Impairment BurdenF
3 causes
Filed pollutant/stressor causes, vs. the national corpus of assessed active units
Assessment CurrencyB+
2022
Reporting cycle this record’s verdicts were last decided in

Squaw Creek Reservoir against the ATTAINS register

Paragraphs are selected by this unit's percentiles and use matrix: different lakes lead with different dimensions. Figures are ATTAINS / portal register arithmetic, not advice.

The signature stat: cause-list length

The standout filed fact is cause-list length: 3 listed impairment causes, a longer list than 90% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.

Every ruled-on use is not supporting

On the uses this filer ruled on, recreation, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.

Squaw Creek Reservoir: Category 5, TMDL still owed

Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Squaw Creek Reservoir. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.

Overall status: not supporting

The filer's overall status for Squaw Creek Reservoir is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.

Mid-pack inside Nevada

Size rank 34 of 50 inside Nevada is mid-pack; the national percentile is the better scale comparison for this unit.

According to the U.S. Environmental Protection Agency's ATTAINS program, Nevada carries 69 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Squaw Creek Reservoir without modification. See our methodology for reporting-unit limits and gauge linking rules.

Reporting cycle
2022
Monitored through 2022 · Nevada Integrated Report
Listing category
Category 5
Uses with verdicts
8
Definitive use assessments
Sources retrieved
2026-08-17
Portal-wide ATTAINS + NWIS pull

The record

Designated-use assessments

Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle. Monitoring behind at least one of these designated-use verdicts ran through 2022, as Nevada filed it. Nevada filed its own confidence on the 8 definitive verdicts it rated: Low. That rating is the filer's, in EPA's own field, and EPA publishes no definition of the four words it offers.

Designated use Group Verdict
Aquatic Life Aquatic-life or related Not Supporting
Filer confidence: Low
Industrial Supply Other Fully Supporting
Filer confidence: Low
Irrigation Other Fully Supporting
Filer confidence: Low
Municipal or Domestic Supply Drinking-water supply designation Fully Supporting
Filer confidence: Low
Propagation of Wildlife Other Fully Supporting
Filer confidence: Low
Recreation Involving Contact with the Water Recreation Not Supporting
Filer confidence: Low
Recreation Not Involving Contact with the Water Recreation Fully Supporting
Filer confidence: Low
Watering of Livestock Other Fully Supporting
Filer confidence: Low
Water and Organisms Aquatic-life or related Not Assessed

The record

Listed impairment causes

Causes the state listed as impairing designated uses of this reservoir, with the cycle each was first listed and the Clean Water Act action recorded against it.

Cause Affected uses First listed Cleanup standing
Dissolved Oxygen Aquatic Life 2024 TMDL priority: Low
Phosphorus Recreation Involving Contact with the Water, Aquatic Life 2024 TMDL priority: Low
Temperature Aquatic Life 2024 TMDL priority: Low

Reading the record

Where Squaw Creek Reservoir sits among peers

70% of Nevada's lakes assessed this deeply also came out mixed

Nevada ruled definitively on 8 designated uses at Squaw Creek Reservoir and found 2 of 8 not supported. The dataset shows 43 Nevada lakes judged to that same depth.

Nevada's assessed lakes are most often judged on 5 or more uses, as this one was.

70 N

Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.

Share of Nevada lakes judged on 8 designated uses with the same outcome
Assessed lakes in Nevada by how many uses were ruled on and how those rulings came out
Less More
Assessed lakes in Nevada by how many uses were ruled on and how those rulings came out (lakes)
12345+
All supported 211013
Mixed Not possible11130 (this record)
None supported 30000

Ringed cell: Squaw Creek Reservoir. Source: EPA ATTAINS, Reporting cycles 1987–2026.

Scale and rank

Squaw Creek Reservoir is one of 69 lake-type waterbodies reported to EPA from Nevada, and one of 50 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 46 assessed acres it ranks 18,326th by assessed size among the 38,628 lakes the dataset carries an area for, counting a state’s repeated filings of one water once, behind 18,325 lakes with a larger one.

Open in the register

The state has not yet filed a definitive fish-consumption verdict for this record; that field populates when it reports it in a future Integrated Report cycle.

In context

Where Squaw Creek Reservoir sits nationally

Assessed size among U.S. lakes

Distribution of assessed acreage across ATTAINS lakes filed with an area, counting a state’s repeated filings of one water once

46 Top 47% larger than 53% of 38,628 lakes

lakes the dataset carries an area for, counting a state’s repeated filings of one water once, bucketed by value

Source EPA ATTAINS · Reporting cycles 1987–2026

Listed causes vs waterbodies carrying a verdict

How many impairment causes U.S. waterbodies with a reported verdict carry

3 Longer than most more listed causes than 90% of 23,610 waterbodies carrying a verdict

named waterbodies carrying a verdict, bucketed by value

Source EPA ATTAINS · Reporting cycles 1987–2026

In both charts each bar is a band and taller bars hold more waterbodies; the dashed line and filled bar mark Squaw Creek Reservoir. Hover or tap any bar for its full count and share.

In context

Nevada context

ATTAINS carries 69 lake-type waterbodies in Nevada, 36 assessed as not supporting at least one use and 17 fully supporting. Among the 50 indexed units there, Squaw Creek Reservoir ranks 16th by listed-cause count (3 listed causes) and 34th by assessed size among the 50 with an area filed; it sits in the not-supporting set (36 statewide) . Its listed causes include Dissolved Oxygen, Phosphorus, and Temperature, which also appear among Nevada's most-filed impairment causes (led by Phosphorus).

Other large assessed lakes in Nevada Assessed acres
Lake Mead Fully Supporting 147,392
Lake Tahoe Not Supporting 122,902
Walker Lake Not Supporting 35,521
Lake Mohave Not Supporting 27,001
Rye Patch Reservoir Not Supporting 16,001
Lahontan Reservoir Not Supporting 14,178

Peers near Squaw Creek Reservoir's size or cause load

Similar assessed acres

Nearest filed extents (46 acres here).

Similar cause load

Nearest listed-cause counts (3 here). Peers already in the acreage column are omitted.

How peers are picked

What to do with this record

  • Assessment verdicts are cycle-based, not real-time. For fish-consumption decisions, your state advisory program is the binding source. Consumption status guide
  • Impairment listings follow the Clean Water Act 303(d) process; a listing is a regulatory finding, not a closure notice. 303(d) explained

PlainLakes renders state assessment decisions and federal gauge observations without modification. It does not issue advisories.

Assessment decisions on this page are rendered directly from state Integrated Report records in EPA's ATTAINS system; gauge figures are daily-value observations from the USGS National Water Information System, no number is typed in by an editor. Overall status, use verdicts, and causes are the state's reported decisions for assessment unit NV02-BL-02-B_00. Counts and percentiles are computed across all lake-type records PlainLakes ingests from ATTAINS. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-17. Primary sources: EPA ATTAINS and USGS National Water Information System.