Greenwood Lake vs Sand Lake
Water quality, depth, fish species, and recreation comparison.
Greenwood Lake and Sand Lake both received the same overall water quality grade of C (Fair). Both are in Lake County, Minnesota.
Greenwood Lake and Sand Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. These two are within a letter of each other on the rubric — Greenwood Lake (C) versus Sand Lake (C). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Greenwood Lake
Very murky, less than 2.1 ft of visibility.
Sand Lake
Murky, only visible to about 4.1 ft.
Side-by-Side Metrics
| Metric | Greenwood Lake | Sand Lake |
|---|---|---|
| Overall Grade | C (Fair) | C (Fair) |
| Water Clarity | 2.1 ft | 4.1 ft Better |
| Phosphorus | 27.5 µg/L | 22 µg/L Better |
| Chlorophyll-a (Algae) | 5.9 µg/L Better | 8 µg/L |
| Maximum Depth | 7 ft | 11 ft Better |
| Surface Area | 1,329 acres | 486 acres |
| Public Access | Yes | Yes |
| Fish Species | 7 | 9 Better |
| Trophic State | eutrophic | eutrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Greenwood Lake or Sand Lake against a different lake.
Verdict
Both lakes earn the same Grade C. The tiebreakers come down to clarity (Greenwood Lake: 2.1 ft, Sand Lake: 4.1 ft) and what you want from the lake. Greenwood Lake has fewer fish species than Sand Lake.
Source: EPA National Aquatic Resource Surveys, 2026.