Clay County Lake Quality
Minnesota, 2 lakes, average grade C (Fair)
Clay County has 2 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. The county average is C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Barnesville Lake (A); the most-stressed is Bjorndahl Lake (F).
Quick Answers for Clay County
Planning a trip? Check special fishing regulations for Barnesville Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Minnesota regulations index.
DNR Reports (2)
Minnesota DNR LakeFinder resources for lakes in Clay County. browse all reports →
- —Fisheries Lake Survey — BarnesvilleFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — BarnesvilleFish Stocking History · MN DNR LakeFinder
All Lakes in Clay County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Barnesville Lake | A | - | 17 ft | 16.5 µg/L |
| 2 | Bjorndahl Lake | F | 2.3 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.