Arrowhead Lake vs Willow Lake
Water quality, depth, fish species, and recreation comparison.
Willow Lake has a higher water quality grade (C, Fair) than Arrowhead Lake (F, Very Poor). Both are in Wisconsin.
Both Arrowhead Lake and Willow Lake sit in Iowa. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are meaningfully apart: Willow Lake grades a C while Arrowhead Lake grades a F. 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 — Willow 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
Very murky, less than 1.8 ft of visibility.
Willow Lake
Murky, only visible to about 4.8 ft.
Side-by-Side Metrics
| Metric | Arrowhead Lake | Willow Lake |
|---|---|---|
| Overall Grade | F (Very Poor) | C (Fair) |
| Water Clarity | 1.8 ft | 4.8 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 53.6 µg/L | 9.5 µg/L |
| Maximum Depth | - | - |
| Surface Area | 15.7 acres | 19 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Willow Lake wins on overall water quality with a Grade C versus Arrowhead Lake's Grade F. Water clarity: 4.8 ft vs 1.8 ft. For fishing diversity, Willow Lake also leads with 0 species.