Island Lake vs Sand Hill Lake
Water quality, depth, fish species, and recreation comparison.
Sand Hill Lake has a higher water quality grade (C, Fair) than Island Lake (F, Very Poor). Both are in Minnesota.
Both Island Lake and Sand Hill Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. Sand Hill Lake (C) is materially cleaner than Island Lake (F). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Sand Hill Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Island Lake
Murky, only visible to about 4.5 ft.
Sand Hill Lake
Moderate clarity, visible to about 6.9 ft.
Side-by-Side Metrics
| Metric | Island Lake | Sand Hill Lake |
|---|---|---|
| Overall Grade | F (Very Poor) | C (Fair) |
| Water Clarity | 4.5 ft | 6.9 ft |
| Phosphorus | 30 µg/L | 26 µg/L |
| Chlorophyll-a (Algae) | 34.3 µg/L | 6.8 µg/L |
| Maximum Depth | 43 ft | 17 ft |
| Surface Area | 616 acres | 479 acres |
| Public Access | Yes | Yes |
| Fish Species | 11 | 6 |
| Trophic State | eutrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Sand Hill Lake wins on overall water quality with a Grade C versus Island Lake's Grade F. Water clarity: 6.9 ft vs 4.5 ft. For more fish-species variety, Island Lake edges ahead with 11 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.