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LakeQuality

Mauvaise Terre Lake vs Otter Lake

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

Otter Lake has a higher water quality grade (D, Poor) than Mauvaise Terre Lake (F, Very Poor). Both are in Wisconsin.

Mauvaise Terre Lake and Otter Lake are both in Illinois — 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 — Mauvaise Terre Lake (F) versus Otter Lake (D). 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.

F

Mauvaise Terre Lake

Morgan County, Wisconsin

No clarity data.

D

Otter Lake

Macoupin County, Wisconsin

Very murky, less than 1.8 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.

MetricMauvaise Terre LakeOtter Lake
Overall GradeF (Very Poor)D (Poor)
Water ClarityNo data1.8 ft
Phosphorus162 µg/L37 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area262 acres760 acres
Public AccessUnknownUnknown
Fish Species00
Trophic Statehypereutrophiceutrophic

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

Verdict

Otter Lake wins on overall water quality with a Grade D versus Mauvaise Terre Lake's Grade F. For fishing diversity, Otter Lake also leads with 0 species.