Madison County Lake Quality
Iowa, 2 lakes, average grade F (Very Poor)
Madison County has 2 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. The county average is F — the most-stressed bracket in our rubric. Most monitored lakes here show persistent nutrient loading and algal pressure.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Badger Creek Max Depth Lake (F) is the cleanest in the county.
Quick Answers for Madison County
Planning a trip? Check special fishing regulations for Badger Creek Max Depth Lake — or check the official Iowa fishing regulations.
All Lakes in Madison County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Badger Creek Max Depth Lake | F | 1.6 ft | - |
| 2 | Cedar Lake | F | 1.6 ft | - |
Other Counties in Iowa
See how Madison County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 15 states.
Where to stay near Madison County
Top-rated places to stay near Madison County
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Madison County?
Get lake water-quality report cards plus the best cabin & lodging deals near Madison County — straight to your inbox. No spam, unsubscribe anytime.
Source: EPA National Aquatic Resource Surveys, 2026.