Utah lake · state assessment record
Gilbert Bay
Assessment decisions reported by Utah to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.
- 559,424
- Assessed acres
- Lake, Saline
- Water type
This waterbody in one line
Gilbert Bay, a lake in Utah, is assessed as fully supporting its assessment entries, with no impairment causes listed in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits among the largest 1% of assessed lakes nationally (38,628 lakes with a filed area); its impairment list is shorter than on half of assessed lakes (0 listed causes). Utah assesses aquatic wildlife (waterfowl, shorebirds, and other) as supported; it reported no verdict on aquatic life itself.
- Fully Supporting
- overall status
- P100
- Assessed size nationally
- P51
- Shorter cause list
- Fully Supporting
- aquatic-life or related
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
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.
Gilbert Bay 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: assessed size
The number that most separates Gilbert Bay nationally is assessed size: 559,424 acres, larger than 100% of the 38,628 lake-type units with an area on file.
Shorter than most cause lists
Only 0 causes on file, shorter than 51% of assessed lake-type units. Pair the short list with the use matrix: a single Not Supporting use can still be the whole story.
Every filed use clears the bar
The filed use determinations for aquatic life are all Fully Supporting. Where an overall IR category still flags the unit, look at the cause list and report standing rather than treating the use row as empty.
IR category in the supporting band
EPA's Integrated Report category for Gilbert Bay is 2. In ATTAINS that band means the assessed uses are supporting (or supporting with other waters in the unit), so the narrative weight shifts to how deep the assessment went and whether monitoring is current, not to a restoration plan.
Overall status: fully supporting
Overall status is Fully Supporting. If an IR category or cause row still appears, it usually reflects a prior listing path or a use the overall rollup does not collapse, read those sections rather than stopping at the tile.
According to the U.S. Environmental Protection Agency's ATTAINS program, Utah carries 143 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Gilbert Bay without modification. See our methodology for reporting-unit limits and gauge linking rules.
The record
Assessment entries
Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle.
| Assessment entry | Group | Verdict |
|---|---|---|
| Aquatic Wildlife (Waterfowl, Shorebirds, and Other) | Aquatic-life or related | Fully Supporting |
| Great Salt Lake - Gilbert Bay | Other | Fully Supporting |
| Recreation and Aesthetics (Frequent Primary Contact) | Recreation | Insufficient Information |
Not every entry above is a designated use: Great Salt Lake - Gilbert Bay is a named segment of the waterbody, not a use. The state files it in the ATTAINS use column, so it carries whatever verdict the state recorded against it.
The record
Listed impairment causes
The state's reported assessment lists no impairment causes for this lake.
Reading the record
Gilbert Bay: Category 2 reading
2 Category 2: some uses supported, others not assessed
Utah filed this assessment unit as Category 2: some designated uses are supported and others were not assessed in this cycle. Absence of a failing verdict is not the same as a full Category 1 finding.
Scale and rank
Gilbert Bay is one of 143 lake-type waterbodies reported to EPA from Utah. It is not among the 84 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 559,424 assessed acres it ranks 6th 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 5 lakes with a larger one.
What this record holds
Utah completed an assessment here and listed no impairment cause, so the record holds a verdict and its supporting use rows but no pollutant to track over time. The state has not yet filed a definitive fish-consumption verdict and a definitive recreation verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
In context
Where Gilbert Bay 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
559,424 Top 1% larger than 99%+ 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
0 Among the shortest cause lists fewer listed causes than 51% 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 Gilbert Bay. Hover or tap any bar for its full count and share.
In context
Utah context
ATTAINS carries 143 lake-type waterbodies in Utah, 77 assessed as not supporting at least one use and 60 fully supporting.
| Other large assessed lakes in Utah | Assessed acres |
|---|---|
| Gunnison Bay Not Assessed | 384,588 |
| Lake Powell Fully Supporting | 149,885 |
| Utah Lake other than Provo Bay Not Supporting | 87,984 |
| Farmington Bay Not Assessed | 77,243 |
| Bear River Bay Not Assessed | 71,681 |
| Bear Lake Fully Supporting | 35,414 |
Peers near Gilbert Bay's size or cause load
Similar assessed acres
Nearest filed extents (559,424 acres here).
- Lake Erie Western Basin Open Water (>3m) · 337,472 acres · OH
- Lake Sakakawea · 318,821 acres · ND
- Lake of the Woods · 301,348 acres · MN
- Lake of the Woods (Main) · 301,348 acres · MN
Similar cause load
Nearest listed-cause counts (0 here). Peers already in the acreage column are omitted.
- 31st Street Harbor · 0 causes · IL
- 42nd Avenue East Beach · 0 causes · MN
- 59th Street Harbor · 0 causes · IL
- 657 Dunleavy (Beach) · 0 causes · MI
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 UT-L-16020310-001_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.