Thayer Lake vs Twelve Mile Lake
Water quality, depth, fish species, and recreation comparison.
Thayer Lake has a higher water quality grade (D, Poor) than Twelve Mile Lake (F, Very Poor). Both are in Union County, Wisconsin.
Thayer Lake and Twelve Mile Lake 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. These two are within a letter of each other on the rubric — Thayer Lake (D) versus Twelve Mile 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.
Thayer Lake
Murky, only visible to about 3.5 ft.
Twelve Mile Lake
Very murky, less than 2.4 ft of visibility.
Side-by-Side Metrics
| Metric | Thayer Lake | Twelve Mile Lake |
|---|---|---|
| Overall Grade | D (Poor) | F (Very Poor) |
| Water Clarity | 3.5 ft | 2.4 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | 34.3 µg/L | 45 µg/L |
| Maximum Depth | - | - |
| Surface Area | 14.1 acres | 633 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
Thayer Lake wins on overall water quality with a Grade D versus Twelve Mile Lake's Grade F. Water clarity: 3.5 ft vs 2.4 ft. For fishing diversity, Thayer Lake also leads with 0 species.