Beaver Lake vs Dale Maffitt Reservoir
Water quality, depth, fish species, and recreation comparison.
Dale Maffitt Reservoir has a higher water quality grade (B, Good) than Beaver Lake (F, Very Poor). Both are in Dallas County, Wisconsin.
Beaver Lake and Dale Maffitt Reservoir 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. Dale Maffitt Reservoir (B) is materially cleaner than Beaver 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 — Dale Maffitt Reservoir 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?
Beaver Lake
Very murky, less than 1.9 ft of visibility.
Dale Maffitt Reservoir
Moderate clarity, visible to about 9.8 ft.
Side-by-Side Metrics
| Metric | Beaver Lake | Dale Maffitt Reservoir |
|---|---|---|
| Overall Grade | F (Very Poor) | B (Good) |
| Water Clarity | 1.9 ft | 9.8 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 62.2 µg/L | 2.5 µg/L |
| Maximum Depth | - | - |
| Surface Area | 34 acres | 230 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Dale Maffitt Reservoir wins on overall water quality with a Grade B versus Beaver Lake's Grade F. Water clarity: 9.8 ft vs 1.9 ft. For fishing diversity, Dale Maffitt Reservoir also leads with 0 species.