Iowa County Lake Quality
Wisconsin, 8 lakes, measured by Wisconsin DNR
Iowa County has 8 monitored 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. 6 of those lakes carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. For Iowa County the spread behind the average matters more than the average itself: a few nutrient-rich lakes among many clear ones produce the same figure as the inverse.
The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Black Hawk Lake.
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Quick Answers for Iowa County
Planning a trip? Check special fishing regulations for Black Hawk Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
Fishing in Iowa County
DNR Reports (7)
Wisconsin DNR Fisheries Survey resources for lakes in Iowa County. browse all reports →
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2023Ludden Lake comprehensive survey 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2022Cox Hollow Lake comprehensive survey 2022Comprehensive Survey · WI DNR · 2022 (PDF)
- 2021Blackhawk Lake comprehensive survey 2021Comprehensive Survey · WI DNR · 2021 (PDF)
- 2018Twin Valley Lake comprehensive survey 2018Comprehensive Survey · WI DNR · 2018 (PDF)
- 2017Blackhawk Lake comprehensive survey 2017Comprehensive Survey · WI DNR · 2017 (PDF)
- 2013Ludden Lake comprehensive survey 2013Comprehensive Survey · WI DNR · 2013 (PDF)
- 2011Lower Wisconsin River channel catfish 2011Fisheries Survey · WI DNR · 2011 (PDF)
All Lakes in Iowa County
8 lakes · 6 ranked on readings, 2 without enough sampling6 lakes ranked on readings · 2 without enough sampling, hidden
| # | Lake | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|
| 1 | Black Hawk LakeIowa | 5 ft | 19.9 µg/L | No recent samples | No recent samples | 42 ft | ✓ Public |
| 2 | Goodwiler LakeIowa | 4.7 ft | 29.7 µg/L | No recent samples | No recent samples | 5 ft | ✓ Public |
| 3 | Kendal LakeIowa | 6.9 ft | 32.7 µg/L | No recent samples | No recent samples | 17 ft | ✓ Public |
| 4 | Ludden LakeIowa | 1.5 ft | 172 µg/L | No recent samples | No recent samples | 14 ft | ✓ Public |
| 5 | Helen LakeIowa | 3.4 ft | 54.7 µg/L | No recent samples | No recent samples | 28 ft | ✓ Public |
| 6 | Avoca LakeIowa | 2 ft | 80.5 µg/L | No recent samples | No recent samples | 10 ft | ✓ Public |
| Twin Valley LakeIowa | No recent samples | No recent samples | No recent samples | No recent samples | 32 ft | ✓ Public | |
| Cox Hollow LakeIowa | No recent samples | No recent samples | No recent samples | No recent samples | 30 ft | ✓ Public |
NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.
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Other Counties in Wisconsin
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Source: the Wisconsin Department of Natural Resources. See data sources.