Isabella County Lake Quality
Michigan, 2 lakes, average grade A (Excellent)
Only 2 lakes in Isabella 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's average grade is A — among the cleanest in Michigan. 1 lakes pull an A on their own, and almost none fall into the D or F brackets.
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 Coldwater Lake Southeast Basin; Nottawa Township (A); the most-stressed is Lake Isabella North Basin; Sherman Township (B).
Where to stay near Isabella County
Top-rated places to stay near Isabella 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 Isabella County?
Get lake water-quality report cards plus the best cabin & lodging deals near Isabella County — straight to your inbox. No spam, unsubscribe anytime.
Quick Answers for Isabella County
Planning a trip? Check special fishing regulations for Coldwater Lake Southeast Basin; Nottawa Township, whether the fish are safe to eat, and the best times to fish — or check the official Michigan fishing regulations.
All Lakes in Isabella County
2 lakes2 graded lakes
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Access |
|---|---|---|---|---|---|---|---|
| 1 | AColdwater Lake Southeast Basin; Nottawa TownshipIsabella | A | 11 ft | 16 µg/L | 1 µg/L | No recent samples | Not recorded |
| 2 | BLake Isabella North Basin; Sherman TownshipIsabella | B | 6.5 ft | 15.5 µg/L | No recent samples | No recent samples | Not recorded |
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Other Counties in Michigan
See how Isabella County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 49 states and 2 Canadian provinces.
Source: EPA National Aquatic Resource Surveys, 2026.