Michigan lake · state assessment record
Diane Lake
Assessment decisions reported by Michigan to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2024 reporting cycle.
- 262
- Assessed acres
- Lake, Freshwater
- Water type
- Hypereutrophic
- Reported trophic class
This waterbody in one line
Diane Lake, a lake in Michigan, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2024). By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P85
- Assessed size nationally
- P10
- 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.
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.
Reading Diane Lake's filed record
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 Diane Lake nationally is assessed size: 261.8 acres, larger than 85% of the 38,628 lake-type units with an area on file.
No ruled-on use clears the bar
On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Diane Lake: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Diane Lake. 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 Diane 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, Michigan carries 4,307 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Diane 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. Michigan filed 2021 as the year this waterbody was last monitored. For the definitive verdicts on this record, Michigan filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them. Michigan filed its own confidence on the 4 definitive verdicts it rated: Good. 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 |
|---|---|---|
| Agriculture | Other | Fully Supporting Filer confidence: Good |
| Industrial Water Supply | Other | Fully Supporting Filer confidence: Good |
| Navigation | Other | Fully Supporting Filer confidence: Good |
| Other Indigenous Aquatic Life and Wildlife | Aquatic-life or related | Not Supporting Filer confidence: Good |
| Cold Water Fishery | Aquatic-life or related | Not Assessed |
| Fish Consumption | Fish-consumption or fishery | Insufficient Information Filer confidence: Good |
| Partial Body Contact Recreation | Recreation | Not Assessed |
| Total Body Contact Recreation | Recreation | Not Assessed |
| Warm Water Fishery | Aquatic-life or related | Not Assessed |
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 |
|---|---|---|---|
| Phosphorus, Total | Other Indigenous Aquatic Life and Wildlife | 2022 | TMDL priority: Low |
| Trophic State Index (Tsi) | Other Indigenous Aquatic Life and Wildlife | 2024 | TMDL priority: Low |
Probable sources
Michigan listed the source of the impairment as unknown. That is the state's own filed value, not a gap in this record: the cause has been identified, the origin has not.
Reading the record
Where Diane Lake sits among peers
16% of Michigan's lakes assessed this deeply also came out mixed
Michigan ruled definitively on 4 designated uses at Diane Lake and found 1 of 4 not supported. The dataset shows 973 Michigan lakes judged to that same depth.
Michigan's assessed lakes are most often judged on 3 uses; this one was judged on 4.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 142 | 85 | 1.9k | 822 | 481 |
| Mixed | Not possible | 38 | 0 | 151 (this record) | 610 |
| None supported | 2 | 6 | 0 | 0 | 0 |
Ringed cell: Diane Lake. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Diane Lake is one of 4,307 lake-type waterbodies reported to EPA from Michigan, and one of 776 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 262 assessed acres it ranks 5,883rd 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 5,882 lakes with a larger one.
Not yet on record
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.
Reported trophic class
Hypereutrophic is the trophic class the filing agency reported to EPA ATTAINS for this assessment unit. It describes nutrient enrichment, not whether the water is safe, and it is not a PlainLakes inference. What the trophic scale measures.
In context
Where Diane 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
262 Top 15% larger than 85% 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 Diane Lake. Hover or tap any bar for its full count and share.
In context
Michigan context
ATTAINS carries 4,307 lake-type waterbodies in Michigan, 807 assessed as not supporting at least one use and 3,457 fully supporting. Among the 776 indexed units there, Diane Lake ranks 158th by listed-cause count (2 listed causes) and 244th by assessed size among the 493 with an area filed; it sits in the not-supporting set (807 statewide) . Its listed causes (Phosphorus, Total; and Trophic State Index (Tsi)) sit outside Michigan's top-five list, which is led by Mercury in Fish Tissue.
| Other large assessed lakes in Michigan | Assessed acres |
|---|---|
| Lake Huron (Michigan Jurisdiction) Not Supporting | 5,815,360 |
| Lake Michigan South of Frankfort (Michigan Jurisdiction) Not Supporting | 5,665,920 |
| St. Marys River Not Supporting | 129,983 |
| Lake St. Clair (Michigan Jurisdiction) Not Supporting | 103,616 |
| Lake Erie (Michigan Jurisdiction) Not Supporting | 71,680 |
| Houghton Lake Not Supporting | 20,066 |
Peers near Diane Lake's size or cause load
Similar assessed acres
Nearest filed extents (262 acres here).
- Round · 262 acres · MN
- Pier Lake · 262 acres · WI
- Spring (Bureau) · 262 acres · IL
- Cold Springs Reservoir · 262 acres · NV
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 MI041000030106-01. 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.