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LakeQuality

Missouri vs Iowa, Lake Water Quality Comparison

A data-driven comparison of lake water quality between Missouri and Iowa, built from EPA Water Quality Portal monitoring data.

MissouriIowa
Total Lakes278209
Average GradeCD
Average Score1.810.85
Grade A Lakes5112
Grade B Lakes1110
Grade C Lakes5516
Grade D Lakes4430
Grade F Lakes5596
Oligotrophic (Cleanest)170
Eutrophic (High Nutrient)9954
Lakes with Invasives133
Improving Trend8995
Declining Trend9282

Analysis

Missouri has 278 graded lakes averaging a C (score 1.81), while Iowa has 209 graded lakes averaging a D (score 0.85). On average water quality, Missouri comes out ahead.Missouri counts 51 Grade A lakes and 17 oligotrophic (clearest-class) lakes, against 12 and 0 for Iowa.

Long-term monitoring shows 89 improving and 92 declining lakes in Missouri, versus 95 improving and 82 declining in Iowa. Dataset coverage varies by state: Missouri has maximum-depth data for 0 lakes and documented fish species on 0, compared with 0 and 0 for Iowa. Where a figure is zero, that state dataset has not yet been ingested — grades there rest on EPA clarity and nutrient measurements alone.

Frequently Asked Questions

Does Missouri or Iowa have cleaner lakes?

Missouri has an average lake grade of C (score 1.81) while Iowa averages D (score 0.85). Missouri has the better average water quality. Grades are computed from EPA Water Quality Portal clarity and nutrient measurements.

Which state has more graded lakes?

Missouri has 278 graded lakes while Iowa has 209. Counts reflect lakes with enough EPA Water Quality Portal monitoring data to grade, not the total number of lakes in each state.