Ann Lake vs Knife Lake
Water quality, depth, fish species, and recreation comparison.
Ann Lake has a higher water quality grade (D, Poor) than Knife Lake (F, Very Poor). Both are in Kanabec County, Minnesota.
Ann Lake and Knife 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 — Ann Lake (D) versus Knife Lake (F). 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.
Ann Lake
Very murky, less than 2 ft of visibility.
Knife Lake
Very murky, less than 2.3 ft of visibility.
Side-by-Side Metrics
| Metric | Ann Lake | Knife Lake |
|---|---|---|
| Overall Grade | D (Poor) | F (Very Poor) |
| Water Clarity | 2 ft | 2.3 ft |
| Phosphorus | 78.5 µg/L | 161.5 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | - | - |
| Surface Area | 363 acres | 1.3K acres |
| Public Access | Unknown | Unknown |
| Fish Species | 1 | 1 |
| Trophic State | eutrophic | hypereutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Ann Lake wins on overall water quality with a Grade D versus Knife Lake's Grade F. Water clarity: 2 ft vs 2.3 ft. For fishing diversity, Ann Lake also leads with 1 species.