Alexander Lake vs Spirit River Flowage Lake
Water quality, depth, fish species, and recreation comparison.
Alexander Lake and Spirit River Flowage Lake both received the same overall water quality grade of D (Nutrient-rich). Both are in Lincoln County, Wisconsin.
Alexander Lake and Spirit River Flowage Lake are both in Wisconsin — 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 close: Alexander Lake (D) and Spirit River Flowage Lake (D) are within one letter of each other on our A–F scale. The per-parameter sub-grades below will show where the small differences actually live.
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.
Alexander Lake
Murky, only visible to about 4 ft.
Spirit River Flowage Lake
Very murky, less than 3 ft of visibility.
Side-by-Side Metrics
| Metric | Alexander Lake | Spirit River Flowage Lake |
|---|---|---|
| Overall Grade | D (Nutrient-rich) | D (Nutrient-rich) |
| Water Clarity | 4 ft Better | 3 ft |
| Phosphorus | 46.2 µg/L Better | 49.1 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 36 ft Better | 25 ft |
| Surface Area | 618 acres | 1,220 acres |
| Public Access | Yes | Yes |
| Fish Species | 6 | 6 |
| Trophic State | eutrophic | 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 Alexander Lake or Spirit River Flowage Lake against a different lake.
Verdict
Both lakes earn the same Grade D. The tiebreakers come down to clarity (Alexander Lake: 4 ft, Spirit River Flowage Lake: 3 ft) and what you want from the lake. Alexander Lake matches its peer on species count.
Source: EPA National Aquatic Resource Surveys, 2026.