Milwaukee County Lake Quality
Wisconsin, 14 lakes, average grade C (Fair)
Milwaukee County has 14 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 C — the middle of the rubric, with one or two lakes pulling the average up or down depending on year.
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. Milwaukee River Lake (C) is the cleanest in the county.
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Quick Answers for Milwaukee County
Planning a trip? Check special fishing regulations for Milwaukee River Lake — or browse the full Wisconsin regulations index.
All Lakes in Milwaukee County
14 lakes · 1 graded, 13 not rated1 graded lake · 13 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|---|
| 1 | CMilwaukee River LakeMilwaukee | C | 5.2 ft | 54 µg/L | 15 µg/L | No recent samples | No recent samples | Not recorded |
| NRMilwaukee Harbor LakeMilwaukee | NR | 8.2 ft | 13 µg/L | 12 µg/L | No recent samples | No recent samples | Not recorded | |
| NRLakeshore State Park Fish ShockingMilwaukee | NR | 8 ft | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRMilwaukee Harbor South Half LakeMilwaukee | NR | 7.2 ft | 21 µg/L | 30 µg/L | No recent samples | No recent samples | Not recorded | |
| NRMilwaukee Harbor LakeMilwaukee | NR | 6.6 ft | 25 µg/L | 23 µg/L | No recent samples | No recent samples | Not recorded | |
| NRMilwaukee Harbor North Half LakeMilwaukee | NR | 7.2 ft | 18 µg/L | 23.5 µg/L | No recent samples | No recent samples | Not recorded | |
| NRMilwaukee Harbor LakeMilwaukee | NR | 7.4 ft | 20 µg/L | 26 µg/L | No recent samples | No recent samples | ✓ Public | |
| NRMilwaukee Harbor LakeMilwaukee | NR | 8.2 ft | 12 µg/L | 12 µg/L | No recent samples | No recent samples | ✓ Public | |
| NRMilwaukee Harbor LakeMilwaukee | NR | 6.6 ft | 59.5 µg/L | 14 µg/L | No recent samples | No recent samples | Not recorded | |
| NRMilwaukee Harbor Estuary LakeMilwaukee | NR | 3.8 ft | No recent samples | No recent samples | No recent samples | No recent samples | ✓ Public | |
| NRMilwaukee Harbor LakeMilwaukee | NR | 8.2 ft | 14 µg/L | 16 µg/L | No recent samples | No recent samples | Not recorded | |
| NRNew Zoo PondMilwaukee | NR | 7.6 ft | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRMallard LakeMilwaukee | NR | 5 ft | No recent samples | No recent samples | No recent samples | 10 ft | Not recorded | |
| NRMilwaukee River LakeMilwaukee | NR | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded |
NR = not rated: the monitoring record does not meet the evidence bar for a grade. 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 Wisconsin
See how Milwaukee County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 39 states and 2 Canadian provinces.
Source: EPA National Aquatic Resource Surveys, 2026.