Macon County Lake Quality
Illinois, 1 lakes, average grade F (Very Poor)
Only 1 lakes in Macon County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. The county average is F — the most-stressed bracket in our rubric. Most monitored lakes here show persistent nutrient loading and algal pressure.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Decatur Lake (F); the most-stressed is Decatur Lake (F).
Quick Answers for Macon County
Planning a trip? Check special fishing regulations for Decatur Lake — or check the official Illinois fishing regulations.
All Lakes in Macon County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Decatur Lake | F | 1.3 ft | 90 µg/L |
Other Counties in Illinois
See how Macon 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 Macon County
Top-rated places to stay near Macon 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 Macon County?
Get lake water-quality report cards plus the best cabin & lodging deals near Macon County — straight to your inbox. No spam, unsubscribe anytime.
Source: EPA National Aquatic Resource Surveys, 2026.