Rathbun Lake vs Unionville Lake
Water quality, depth, fish species, and recreation comparison.
Rathbun Lake has a higher water quality grade (D, Poor) than Unionville Lake (F, Very Poor).
This comparison crosses state lines: Rathbun Lake 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: Rathbun Lake (D) 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.
Rathbun Lake
Very murky, less than 3 ft of visibility.
Unionville Lake
Very murky, less than 1.6 ft of visibility.
Side-by-Side Metrics
| Metric | Rathbun Lake | Unionville Lake |
|---|---|---|
| Overall Grade | D (Poor) | F (Very Poor) |
| Water Clarity | 3 ft | 1.6 ft |
| Phosphorus | No data | 129.5 µg/L |
| Chlorophyll-a (Algae) | 15.3 µg/L | 57.5 µg/L |
| Maximum Depth | - | - |
| Surface Area | 11.0K 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
Rathbun Lake wins on overall water quality with a Grade D versus Unionville Lake's Grade F. Water clarity: 3 ft vs 1.6 ft. For fishing diversity, Rathbun Lake also leads with 0 species.