Charles Mill Reservoir vs Tappan Lake
Water quality, depth, fish species, and recreation comparison.
Charles Mill Reservoir and Tappan Lake both received the same overall water quality grade of F (Very Poor). Both are in Wisconsin.
Both Charles Mill Reservoir and Tappan Lake sit in Ohio. 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. These two are within a letter of each other on the rubric — Charles Mill Reservoir (F) versus Tappan Lake (F). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
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.
Charles Mill Reservoir
Very murky, less than 0.9 ft of visibility.
Tappan Lake
Very murky, less than 1.8 ft of visibility.
Side-by-Side Metrics
| Metric | Charles Mill Reservoir | Tappan Lake |
|---|---|---|
| Overall Grade | F (Very Poor) | F (Very Poor) |
| Water Clarity | 0.9 ft | 1.8 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | - | - |
| Surface Area | 1.4K acres | 2.4K acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | hypereutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade F. The tiebreakers come down to clarity (Charles Mill Reservoir: 0.9 ft, Tappan Lake: 1.8 ft) and what you want from the lake. Charles Mill Reservoir matches its peer on species count.