Flat Lake vs North Tamarac Lake
Water quality, depth, fish species, and recreation comparison.
Flat Lake has a higher water quality grade (A, Excellent) than North Tamarac Lake (D, Nutrient-rich). Both are in Becker County, Minnesota.
Flat Lake and North Tamarac 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: Flat Lake grades a A while North Tamarac Lake grades a D. 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 — Flat 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?
Flat Lake
Good clarity, visible to about 11.2 ft.
North Tamarac Lake
Murky, only visible to about 3.9 ft.
Side-by-Side Metrics
| Metric | Flat Lake | North Tamarac Lake |
|---|---|---|
| Overall Grade | A (Excellent) Better | D (Nutrient-rich) |
| Water Clarity | 11.2 ft Better | 3.9 ft |
| Phosphorus | 13 µg/L Better | 36 µg/L |
| Chlorophyll-a (Algae) | 3.7 µg/L Better | 21.4 µg/L |
| Maximum Depth | - | 17 ft |
| Surface Area | 1,754 acres | 1,442 acres |
| Public Access | No | Yes |
| Fish Species | 0 | 12 Better |
| Trophic State | mesotrophic | 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 Flat Lake or North Tamarac Lake against a different lake.
Verdict
Flat Lake wins on overall water quality with a Grade A versus North Tamarac Lake's Grade D. Water clarity: 11.2 ft vs 3.9 ft. For more fish-species variety, North Tamarac Lake edges ahead with 12 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.