Ohio Great Lakes waterbody · state assessment record
Lake Erie Western Basin Open Water (>3m)
Assessment decisions reported by Ohio to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle, a cycle that is open for public comment.
- 527.30
- Assessed square miles
- Great Lakes Open Water
- Water type
This waterbody in one line
Lake Erie Western Basin Open Water (>3m), a Great Lakes waterbody in Ohio, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2026), a cycle that is open for public comment. 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). Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P100
- Assessed size nationally
- P10
- Shorter cause list
- Not Supporting
- fish consumption
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.
How Lake Erie Western Basin Open Water (>3m) reads against 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 Lake Erie Western Basin Open Water (>3m) nationally is assessed size: 337,472 acres, larger than 100% of the 38,628 lake-type units with an area on file.
Every filed use falls short
On the uses this filer ruled on, fish consumption, recreation, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Lake Erie Western Basin Open Water (>3m): Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Lake Erie Western Basin Open Water (>3m). Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
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 Lake Erie Western Basin Open Water (>3m) 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, Ohio carries 7 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake Erie Western Basin Open Water (>3m) 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. Monitoring behind at least one of these designated-use verdicts ran through 2024, as Ohio filed it. For the definitive verdicts on this record, Ohio filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them.
| Designated use | Group | Verdict |
|---|---|---|
| Human Health - Fish Consumption | Fish-consumption or fishery | Not Supporting |
| Recreation - Bathing Waters | Recreation | Not Supporting |
| Water Supply - Public Drinking | Drinking-water supply designation | Not Supporting |
| Aquatic Life - Exceptional Warmwater Habitat | Aquatic-life or related | Not Assessed |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this Great Lakes waterbody, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Algae | Water Supply - Public Drinking, Recreation - Bathing Waters | 2020 | TMDL approved |
| PCBs in Fish Tissue | Human Health - Fish Consumption | 2020 | TMDL priority: Medium |
Reading the record
Where Lake Erie Western Basin Open Water (>3m) sits among peers
10% of the country's lakes assessed this deeply also had no use supported
Ohio ruled definitively on 3 designated uses at Lake Erie Western Basin Open Water (>3m) and found none of them supported. The dataset shows 4,601 lakes nationally judged to that same depth.
The country's assessed lakes are most often judged on 1 use; this one was judged on 3.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 5.8k | 2.2k | 2.4k | 1.5k | 1.7k |
| Mixed | Not possible | 3.5k | 1.7k | 1.5k | 1.3k |
| None supported | 2.6k | 1.2k | 462 (this record) | 315 | 110 |
Ringed cell: Lake Erie Western Basin Open Water (>3m). Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake Erie Western Basin Open Water (>3m) is one of 7 lake-type waterbodies reported to EPA from Ohio, and one of 7 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 527.30 square miles (337,472 acres) it ranks 8th 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 7 lakes with a larger one.
Awaiting a filing
The state has not yet filed a definitive aquatic-life verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
In context
Where Lake Erie Western Basin Open Water (>3m) 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
527 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 Lake Erie Western Basin Open Water (>3m). Hover or tap any bar for its full count and share.
In context
Ohio context
ATTAINS carries 7 lake-type waterbodies in Ohio, 7 assessed as not supporting at least one use and 0 fully supporting. Among the 7 indexed units there, Lake Erie Western Basin Open Water (>3m) ranks 5th by listed-cause count (2 listed causes) and 2nd by assessed size among the 7 with an area filed; it sits in the not-supporting set (7 statewide) . Its listed causes include Algae and PCBs in Fish Tissue, which also appear among Ohio's most-filed impairment causes (led by PCBs in Fish Tissue).
| Other large assessed lakes in Ohio | Assessed acres |
|---|---|
| Lake Erie Central Basin Open Water (>3m) Not Supporting | 1,628,787 |
| Lake Erie Sandusky Basin Open Water (>3m) Not Supporting | 231,494 |
| Lake Erie Sandusky Basin Shoreline (<=3m) Not Supporting | 43,526 |
| Lake Erie Western Basin Shoreline (<=3m) Not Supporting | 30,643 |
| Lake Erie Central Basin Shoreline (<=3m) Not Supporting | 8,570 |
| Lake Erie Islands Shoreline (<=3m) Not Supporting | 3,194 |
Peers near Lake Erie Western Basin Open Water (>3m)'s size or cause load
Similar assessed acres
Nearest filed extents (337,472 acres here).
- Lake Sakakawea · 318,821 acres · ND
- Lake of the Woods · 301,348 acres · MN
- Lake of the Woods (Main) · 301,348 acres · MN
- Gunnison Bay · 384,588 acres · UT
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
- The fish-consumption use is assessed as not supporting. Before eating fish from this Great Lakes waterbody, check your state fish-advisory program for species-specific meal limits. 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 OHLE041202000301. 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.