Long Lake vs Portage Lake
Water quality, depth, fish species, and recreation comparison.
Long Lake has a higher water quality grade (A, Excellent) than Portage Lake (C, Fair). Both are in Hubbard County, Minnesota.
Long Lake and Portage 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: Long Lake grades a A while Portage 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 — Long 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?
Long Lake
Good clarity, visible to about 11.2 ft.
Portage Lake
Murky, only visible to about 5.7 ft.
Side-by-Side Metrics
| Metric | Long Lake | Portage Lake |
|---|---|---|
| Overall Grade | A (Excellent) | C (Fair) |
| Water Clarity | 11.2 ft | 5.7 ft |
| Phosphorus | 10 µg/L | 28 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | - | - |
| Surface Area | 1.9K acres | 422 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 1 | 1 |
| Trophic State | oligotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Long Lake wins on overall water quality with a Grade A versus Portage Lake's Grade C. Water clarity: 11.2 ft vs 5.7 ft. For fishing diversity, Long Lake also leads with 1 species.