Arrowhead Lake vs Black Hawk Lake
Water quality, depth, fish species, and recreation comparison.
Arrowhead Lake has a higher water quality grade (C, Fair) than Black Hawk Lake (F, Very Poor). Both are in Sac County, Wisconsin.
Arrowhead Lake and Black Hawk Lake are both in Iowa — 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. Arrowhead Lake (C) is materially cleaner than Black Hawk Lake (F). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Arrowhead 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?
Arrowhead Lake
Murky, only visible to about 5.6 ft.
Black Hawk Lake
Very murky, less than 0.9 ft of visibility.
Side-by-Side Metrics
| Metric | Arrowhead Lake | Black Hawk Lake |
|---|---|---|
| Overall Grade | C (Fair) | F (Very Poor) |
| Water Clarity | 5.6 ft | 0.9 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 7.1 µg/L | 54.1 µg/L |
| Maximum Depth | - | - |
| Surface Area | 110 acres | 920 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | hypereutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Arrowhead Lake wins on overall water quality with a Grade C versus Black Hawk Lake's Grade F. Water clarity: 5.6 ft vs 0.9 ft. For fishing diversity, Arrowhead Lake also leads with 0 species.