Colby Lake vs Whitewater Lake
Water quality, depth, fish species, and recreation comparison.
Whitewater Lake has a higher water quality grade (A, Excellent) than Colby Lake (C, Fair). Both are in St. Louis County, Minnesota.
Colby Lake and Whitewater 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. The grades are meaningfully apart: Whitewater Lake grades a A while Colby Lake grades a C. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.
For a recreational visitor, the wider grade gap is decisive — Whitewater 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?
Colby Lake
Murky, only visible to about 3.5 ft.
Whitewater Lake
Crystal clear, you can see 15.4 ft down.
Side-by-Side Metrics
| Metric | Colby Lake | Whitewater Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 3.5 ft | 15.4 ft |
| Phosphorus | 22 µg/L | 14 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 30 ft | 73 ft |
| Surface Area | 517.72 acres | 1.2K acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| Trophic State | eutrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Whitewater Lake wins on overall water quality with a Grade A versus Colby Lake's Grade C. Water clarity: 15.4 ft vs 3.5 ft. For fishing diversity, Whitewater Lake also leads with 1 species.