Olmsted County Lake Quality
Minnesota, 5 lakes, average grade D (Poor)
Olmsted County has 5 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-wide average grade is D — water quality issues are persistent across most of the monitored basins. 2 lakes fall into the F bracket outright.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Bamber Lake (A) is the cleanest in the county.
Quick Answers for Olmsted County
Planning a trip? Check special fishing regulations for Bamber Lake, and the best times to fish — or browse the full Minnesota regulations index.
DNR Reports (6)
Minnesota DNR LakeFinder resources for lakes in Olmsted County. browse all reports →
- —Fisheries Lake Survey — ZumbroFisheries Lake Survey · MN DNR LakeFinder
- —Fisheries Lake Survey — SilverFisheries Lake Survey · MN DNR LakeFinder
- —Fisheries Lake Survey — ShadyFisheries Lake Survey · MN DNR LakeFinder
- —Public Water Access Sites — SilverPublic Water Access Sites · MN DNR LakeFinder
- —Fish Stocking History — ZumbroFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — ZumbroPublic Water Access Sites · MN DNR LakeFinder
All Lakes in Olmsted County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Bamber Lake | A | 14.1 ft | - | 11 µg/L |
| 2 | Zumbro Lake | D | 3.9 ft | 43 ft | 69 µg/L |
| 3 | Shady Lake | D | 3.6 ft | 13 ft | - |
| 4 | Silver Lake | F | 2 ft | 11 ft | - |
| 5 | Manor Woods Pond | F | 2.5 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.