Some of these decisions are not final. 7 of these 7 records carry a verdict Ohio decided in its 2026 Integrated Report, which is open for public comment, so they can change before the cycle is submitted to EPA. They are counted in every figure on this page.
State water-quality picture · #49 by reported lake-type waterbodies
Ohio lakes and reservoirs
Every figure on this page is computed from the assessment decisions Ohio reported to the U.S. Environmental Protection Agency under Clean Water Act sections 303(d) and 305(b) (reporting cycles 2026), plus daily water-level observations from the U.S. Geological Survey.
- 7
- Reported waterbodies
- 7
- Not supporting a use
- 7
- Fish use not supporting
- 0
- Gauged lakes
Ohio in one line
7 lake-type waterbodies in Ohio are reported to EPA ATTAINS across reporting cycles 2026: 7 assessed as not supporting at least one designated use, 0 fully supporting, and 0 without a definitive overall verdict. The most-listed impairment cause is PCBs in Fish Tissue, on 7 waterbodies.
- 7
- reported waterbodies
- 7
- not supporting a use
- 0
- fully supporting
- 0
- lakes with a linked USGS gauge
An unassessed waterbody is neither confirmed clean nor confirmed impaired; states assess on multi-year cycles.
Ohio's smaller reported lake-type inventory
At 7 units, Ohio is in the lowest third of state lake-type registers. The charts below describe that compact filing set, not a national-scale inventory.
Data updated 2026-08-17
According to the U.S. Environmental Protection Agency's ATTAINS program, Ohio reported 7 lake-type waterbodies in Ohio in the August 2026 extract. See our methodology for filer attribution and multi-year reporting cycles.
Most-listed impairment causes in Ohio
Waterbodies carrying each listed cause, most first
- PCBs in Fish Tissue
PCBs in Fish Tissue
7 waterbodies
- Algae
Algae
5 waterbodies
- Escherichia coli (E. coli)
Escherichia coli (E. coli)
4 waterbodies
- Non-Native Fish/Shellfish/Zooplankton
Non-Native Fish/Shellfish/Zooplankton
4 waterbodies
- Nutrients
Nutrients
4 waterbodies
What this shows PCBs in Fish Tissue is the most-listed impairment cause in Ohio, on 7 of the lake-type waterbodies reported there.
Assessment outcomes in Ohio
Overall-status mix across reported lake-type waterbodies
- Not supporting a use
Not supporting a use
7 waterbodies
- Fully supporting 0
Fully supporting
0 waterbodies
- No definitive verdict 0
No definitive verdict
0 waterbodies
What this shows Most reported waterbodies in Ohio do not yet carry a definitive overall verdict.
By size
Largest assessed lakes in Ohio
By assessed acreage as reported in ATTAINS. Acreage is the assessed unit's size, which can differ from a lake's full surface area.
| # | Waterbody | Assessed acres |
|---|---|---|
| 1 | Lake Erie Central Basin Open Water (>3m) Not Supporting | 1,628,787 |
| 2 | Lake Erie Western Basin Open Water (>3m) Not Supporting | 337,472 |
| 3 | Lake Erie Sandusky Basin Open Water (>3m) Not Supporting | 231,494 |
| 4 | Lake Erie Sandusky Basin Shoreline (<=3m) Not Supporting | 43,526 |
| 5 | Lake Erie Western Basin Shoreline (<=3m) Not Supporting | 30,643 |
| 6 | Lake Erie Central Basin Shoreline (<=3m) Not Supporting | 8,570 |
| 7 | Lake Erie Islands Shoreline (<=3m) Not Supporting | 3,194 |
By cause count
Most-listed waterbodies in Ohio
Waterbodies carrying the most listed impairment causes among the lake-type units reported by Ohio.
| # | Waterbody | Listed causes |
|---|---|---|
| 1 | Lake Erie Sandusky Basin Shoreline (<=3m) Not Supporting | 8 |
| 2 | Lake Erie Islands Shoreline (<=3m) Not Supporting | 7 |
| 2 | Lake Erie Western Basin Shoreline (<=3m) Not Supporting | 7 |
| 4 | Lake Erie Central Basin Shoreline (<=3m) Not Supporting | 6 |
| 5 | Lake Erie Sandusky Basin Open Water (>3m) Not Supporting | 2 |
| 5 | Lake Erie Western Basin Open Water (>3m) Not Supporting | 2 |
| 7 | Lake Erie Central Basin Open Water (>3m) Not Supporting | 1 |
4 of the 7 rows in this table tie on the ranked value: 2 at 7 (rank 2), 2 at 2 (rank 5). Tied rows share a rank and are listed in no meaningful order; where a tie reaches the top the medal is shared, because nothing separates those rows.
States with similar inventory scale or impairment load
Two EPA ATTAINS peer sets outside Ohio. The reporting-practice chart above stays on definitive-verdict share; these neighborhoods are cross-state nearest neighbors on register size and not-supporting counts.
Comparable register size
Nearest states by lake-type units on the register (7 here).
Similar not-supporting load
Nearest states by units assessed not supporting a use (7 here). Inventory peers above are omitted.
- Alaska · 7 not supporting · 0 off
- Mississippi · 14 not supporting · 7 off
- Maine · 31 not supporting · 24 off
- Arizona · 34 not supporting · 27 off
Peers are nearest-neighbor matches on EPA ATTAINS register size and not-supporting counts among states with at least 25 reported units. Impairment peers skip states already listed in the inventory column so the two link sets stay distinct.
Using this state picture
- Assessment coverage varies by state; Ohio's reported universe reflects its own monitoring program, so cross-state comparisons need the definitive-verdict share, not raw counts. National rankings
- Fish-consumption verdicts here are assessment decisions. Species-level meal advice comes from the state fish-advisory program. Consumption guide
- Browse every named Ohio waterbody with a populated record. Browse waterbodies
PlainLakes renders state assessment decisions and federal gauge observations without modification.
Figures on this page are computed from the assessment decisions Ohio reported to EPA's ATTAINS system and from USGS National Water Information System daily values, no number is typed in by an editor. State counts aggregate every lake-type assessment unit reported by Ohio, including unnamed units that never receive their own page. 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.