Indiana Great Lakes waterbody · state assessment record
Lake Michigan Shoreline
Assessment decisions reported by Indiana to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 9.13
- Miles of shoreline
- Great Lakes Shoreline
- Water type
This waterbody in one line
Lake Michigan Shoreline, a Great Lakes waterbody in Indiana, 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). Its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as fully supporting. Indiana assesses human health and wildlife as not supported; it reported no verdict on fish consumption itself.
- Not Supporting
- overall status
- P10
- Shorter cause list
- Fully Supporting
- aquatic life
- Not Supporting
- fish-consumption or fishery
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 Michigan Shoreline 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: cause-list length
The standout filed fact is cause-list length: 2 listed impairment causes, a longer list than 80% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.
The uses disagree
This record splits: Not Supporting on fish consumption, Fully Supporting on recreation, aquatic life. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Lake Michigan Shoreline: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Lake Michigan Shoreline. 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 Lake Michigan Shoreline 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, Indiana carries 1,588 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake Michigan Shoreline 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. Indiana filed 2024 as the year this waterbody was last monitored. Indiana filed its own confidence on the one definitive verdict 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 |
|---|---|---|
| Full Body Contact | Recreation | Fully Supporting |
| Human Health and Wildlife | Fish-consumption or fishery | Not Supporting Filer confidence: Good |
| Warm Water Aquatic Life | Aquatic-life or related | Fully Supporting |
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 |
|---|---|---|---|
| Mercury in Fish Tissue | Human Health and Wildlife | 1998 | TMDL priority: Medium |
| PCBs in Fish Tissue | Human Health and Wildlife | 1998 | TMDL priority: Low |
Probable sources
Indiana 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 Lake Michigan Shoreline sits among peers
12 of 16 Indiana lakes assessed this deeply also came out mixed
Indiana ruled definitively on 3 designated uses at Lake Michigan Shoreline and found 1 of 3 not supported. The dataset shows 16 Indiana lakes judged to that same depth.
Indiana's assessed lakes are most often judged on 1 use; this one was judged on 3.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 79 | 16 | 1 | 0 | 0 |
| Mixed | Not possible | 38 | 12 (this record) | 5 | 0 |
| None supported | 72 | 15 | 3 | 0 | 0 |
Ringed cell: Lake Michigan Shoreline. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake Michigan Shoreline is one of 1,588 lake-type waterbodies reported to EPA from Indiana, and one of 162 whose reported record carries enough populated assessment or gauge data for this site to list and index it. Indiana reports this unit as 9.13 miles of shoreline rather than a surface area, so it is not ranked against the acreage figures elsewhere on this site.
In context
Where Lake Michigan Shoreline sits nationally
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 Michigan Shoreline. Hover or tap any bar for its full count and share.
In context
Indiana context
ATTAINS carries 1,588 lake-type waterbodies in Indiana, 145 assessed as not supporting at least one use and 96 fully supporting. Among the 162 indexed units there, Lake Michigan Shoreline ranks 36th by listed-cause count (2 listed causes) ; it sits in the not-supporting set (145 statewide) . Its listed causes include Mercury in Fish Tissue and PCBs in Fish Tissue, which also appear among Indiana's most-filed impairment causes (led by PCBs in Fish Tissue).
| Other large assessed lakes in Indiana | Assessed acres |
|---|---|
| Lake Michigan (Not Indexed) (Salmonid) (Osrw) Not Supporting | 154,176 |
| Patoka Reservoir (Pws) Fully Supporting | 8,880 |
| Monroe Reservoir (Lower) (Pws) Not Supporting | 6,863 |
| Brookville Reservoir Not Supporting | 5,260 |
| Monroe Reservoir (Upper) (Pws) Not Supporting | 3,887 |
| Wawasee, Lake Not Supporting | 3,410 |
Lakes near Lake Michigan Shoreline's cause load
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 listing here is on a fishery use, not on fish consumption, and this state reported no consumption verdict for this Great Lakes waterbody. Your state fish-advisory program is the source for whether the catch is safe to eat. 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 INC0163_G1093. 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.