Corydon Reservoir vs Unionville Lake
Water quality, depth, fish species, and recreation comparison.
Corydon Reservoir and Unionville Lake both received the same overall water quality grade of F (Very Poor).
This comparison crosses state lines: Corydon Reservoir in Iowa versus Unionville Lake in Missouri. The LakeGrade rubric is uniform across both, but the underlying monitoring programs differ in subtle ways worth noting. The grades are close: Corydon Reservoir (F) and Unionville Lake (F) are within one letter of each other on the LakeGrade rubric. 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.
Corydon Reservoir
Very murky, less than 1.9 ft of visibility.
Unionville Lake
Very murky, less than 1.6 ft of visibility.
Side-by-Side Metrics
| Metric | Corydon Reservoir | Unionville Lake |
|---|---|---|
| Overall Grade | F (Very Poor) | F (Very Poor) |
| Water Clarity | 1.9 ft | 1.6 ft |
| Phosphorus | No data | 129.5 µg/L |
| Chlorophyll-a (Algae) | 44 µg/L | 57.5 µg/L |
| Maximum Depth | - | - |
| Surface Area | 66.9 acres | 75 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
Both lakes earn the same Grade F. The tiebreakers come down to clarity (Corydon Reservoir: 1.9 ft, Unionville Lake: 1.6 ft) and what you want from the lake. Corydon Reservoir matches its peer on species count.