California lake · state assessment record
Searles Lake
Assessment decisions reported by California to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2020 reporting cycle.
- 29,632
- Assessed acres
- Lake, Saline
- Water type
This waterbody in one line
Searles Lake, a lake in California, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2020). By assessed acreage it sits among the largest 1% of assessed lakes nationally (38,628 lakes with a filed area); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes).
- Not Supporting
- overall status
- P100
- Assessed size nationally
- P10
- Shorter cause list
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.
Where Searles Lake stands in the filed 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 Searles Lake nationally is assessed size: 29,632 acres, larger than 100% of the 38,628 lake-type units with an area on file.
Searles Lake: Category 4B reading
Category 4B says other pollution-control requirements are expected to resolve the impairment on Searles Lake without a TMDL. The decisive documents are those control requirements, not a load allocation.
Longer than most cause lists
2 listed causes puts this unit above 80% of assessed lake-type records by list length. Treat that as a coding-and-sampling signal: states that split pollutants finely mint longer lists without proving worse water.
Overall status: not supporting
The filer's overall status for Searles Lake is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
According to the U.S. Environmental Protection Agency's ATTAINS program, California carries 607 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Searles Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.
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.
| Designated use | Group | Verdict |
|---|---|---|
| Wildlife Habitat | Other | Not Supporting |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this lake, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Petroleum Hydrocarbons | Wildlife Habitat | 2018 | 4B Restoration Approach |
| Salinity/Total Dissolved Solids/Chlorides | Wildlife Habitat | 2018 | 4B Restoration Approach |
Probable sources named by the state
Each source below is listed under the cause the state filed it against, and carries the word the state filed with it — confirmed, or suspected.
- Petroleum Hydrocarbons
- Industrial Point Source Discharge (suspected)
California also recorded the source of at least one listing here as unknown, including for Salinity/Total Dissolved Solids/Chlorides.
Reading the record
Searles Lake: Category 4B reading
4B Category 4B: impaired, other controls in place (not a TMDL path)
California filed this assessment unit as Category 4B: impaired, with other controls in place rather than a pollutant-budget TMDL under 303(d).
Scale and rank
Searles Lake is one of 607 lake-type waterbodies reported to EPA from California. It is not among the 195 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 29,632 assessed acres it ranks 104th 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 103 lakes with a larger one.
Awaiting a filing
The state has not yet filed a definitive fish-consumption verdict, a definitive recreation verdict, and a definitive aquatic-life verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
In context
Where Searles Lake 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
29,632 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
2 Longer than most more listed causes than 80% 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 Searles Lake. Hover or tap any bar for its full count and share.
In context
California context
ATTAINS carries 607 lake-type waterbodies in California, 202 assessed as not supporting at least one use and 22 fully supporting.
| Other large assessed lakes in California | Assessed acres |
|---|---|
| Salton Sea Not Supporting | 233,045 |
| Tahoe, Lake Not Supporting | 84,092 |
| Goose Lake (Modoc County) Not reported | 62,385 |
| Honey Lake Not Supporting | 55,526 |
| Klamath River HU, Tule Lake and Lower Klamath Lake National Wildlife Refuge Not Supporting | 48,791 |
| Mono Lake Not Supporting | 45,299 |
Peers near Searles Lake's size or cause load
Similar assessed acres
Nearest filed extents (29,632 acres here).
- Millwood Lake · 29,500 acres · AR
- Oologah Lake · 29,460 acres · OK
- Walter F. George Lake · 29,890 acres · GA
- Lake Koocanusa · 28,875 acres · MT
Similar cause load
Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.
- 12th St. Beach · 2 causes · IL
- 31st St. Beach · 2 causes · IL
- 49th St. Beach · 2 causes · IL
- 57th St. Beach · 2 causes · IL
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 CAL6211000019990129093321. 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.