Skip to main content
LakeQuality

Diamond Lake vs Lake Keomah

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

Diamond Lake and Lake Keomah both received the same overall water quality grade of F (Very Poor). Both are in Wisconsin.

Diamond Lake and Lake Keomah 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: Diamond Lake (F) and Lake Keomah (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.

F

Diamond Lake

Poweshiek County, Wisconsin

Very murky, less than 1.6 ft of visibility.

F

Lake Keomah

Mahaska County, Wisconsin

Very murky, less than 1.5 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.

MetricDiamond LakeLake Keomah
Overall GradeF (Very Poor)F (Very Poor)
Water Clarity1.6 ft1.5 ft
PhosphorusNo dataNo data
Chlorophyll-a (Algae)44.6 µg/L63 µg/L
Maximum Depth--
Surface Area93 acres82 acres
Public AccessUnknownUnknown
Fish Species00
Trophic Stateeutrophichypereutrophic

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 (Diamond Lake: 1.6 ft, Lake Keomah: 1.5 ft) and what you want from the lake. Diamond Lake matches its peer on species count.