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LakeQuality

Thayer Lake vs Three Mile Lake

Water quality, depth, fish species, and recreation comparison.

Thayer Lake and Three Mile Lake both received the same overall water quality grade of D (Poor). Both are in Union County, Wisconsin.

Thayer Lake and Three 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. The grades are close: Thayer Lake (D) and Three Mile Lake (D) 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.

D

Thayer Lake

Union County, Wisconsin

Murky, only visible to about 3.5 ft.

D

Three Mile Lake

Union County, Wisconsin

Very murky, less than 2.7 ft of visibility.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricThayer LakeThree Mile Lake
Overall GradeD (Poor)D (Poor)
Water Clarity3.5 ft2.7 ft
PhosphorusNo dataNo data
Chlorophyll-a (Algae)34.3 µg/L28.4 µg/L
Maximum Depth--
Surface Area14.1 acres880 acres
Public AccessUnknownUnknown
Fish Species00
Trophic Stateeutrophiceutrophic

Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).

Verdict

Both lakes earn the same Grade D. The tiebreakers come down to clarity (Thayer Lake: 3.5 ft, Three Mile Lake: 2.7 ft) and what you want from the lake. Thayer Lake matches its peer on species count.