Washtenaw County Lake Quality
Michigan, 13 lakes, average grade A (Excellent)
Washtenaw County has 13 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's average grade is A — among the cleanest in Michigan. 4 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 Glacier Lake (A); the most-stressed is Little Portage Lake (B).
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Quick Answers for Washtenaw County
Planning a trip? Check special fishing regulations for Glacier Lake, whether the fish are safe to eat, and the best times to fish — or check the official Michigan fishing regulations.
Fishing in Washtenaw County
All Lakes in Washtenaw County
13 lakes · 5 graded, 8 not rated5 graded lakes · 8 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|---|
| 1 | AGlacier LakeWashtenaw | A | 6 ft | 13.5 µg/L | 2.2 µg/L | No recent samples | No recent samples | Not recorded |
| 2 | ANorth LakeWashtenaw | A | 12.5 ft | 13 µg/L | 3.7 µg/L | No recent samples | 58 ft | ✓ Public |
| 3 | ACrystal LakeWashtenaw | A | 12.5 ft | 8.5 µg/L | 1.6 µg/L | No recent samples | No recent samples | Not recorded |
| 4 | ASugarloaf LakeWashtenaw | A | 9.5 ft | 10 µg/L | 1.9 µg/L | No recent samples | 10 ft | ✓ Public |
| 5 | BLittle Portage LakeWashtenaw | B | 11 ft | 14.5 µg/L | No recent samples | No recent samples | No recent samples | Not recorded |
| NRPleasant LakeWashtenaw | NR | 7.5 ft | No recent samples | No recent samples | No recent samples | 36 ft | Not recorded | |
| NRBase Line LakeWashtenaw | NR | 11 ft | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRBruin LakeWashtenaw | NR | 11.5 ft | No recent samples | No recent samples | No recent samples | 48 ft | ✓ Public | |
| NRSilver LakeWashtenaw | NR | 11.5 ft | No recent samples | No recent samples | No recent samples | No recent samples | ✓ Public | |
| NRFirst Sister LakeWashtenaw | NR | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRSecond Sister LakeWashtenaw | NR | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRFord LakeWashtenaw | NR | 3 ft | 36 µg/L | No recent samples | No recent samples | 30 ft | Not recorded | |
| NRLong LakeWashtenaw | NR | 9 ft | No recent samples | No recent samples | No recent samples | No recent samples | ✓ Public |
NR = not rated: there is not enough recent sampling to support a letter. That is EPA Integrated Reporting Category 3 (insufficient information), not a failing grade. How grading works.
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 Washtenaw 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.