Curly-Leaf Pondweed
Invasive SpeciesFound in 420 lakes
Curly-Leaf Pondweed appears on state infested-waters lists for 420 surface waters. Boaters and anglers moving gear in or out of those lakes carry a clean-drain-dry obligation under state law. At 420 infested lakes, Curly-Leaf Pondweed is past the "containable" stage in the upper Midwest — every public boat-launch on uninfested water should now assume incoming boaters may be carrying it.
The presence of Curly-Leaf Pondweed does not directly change a lake's letter grade — the grade measures the water itself, not the species living in it. Invasive presence is still worth reading alongside the grade.
Lakes with Curly-Leaf Pondweed
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Big Cedar Lake-North Site-Near West Bend | Washington | WI | A | 105 ft |
| Big Cedar Lake-South Site-Near West Bend | Washington | WI | A | 105 ft |
| Green Lake | Green Lake | WI | A | 236 ft |
| Lake Beulah | Walworth | WI | A | 58 ft |
| Okauchee Lake | Waukesha | WI | A | 90 ft |
| Geneva Lake | Walworth | WI | A | 135 ft |
| Powers Lake | Kenosha | WI | A | 33 ft |
| Lac Courte Oreilles Lake | Sawyer | WI | A | 90 ft |
| Whitefish Lake | Sawyer | WI | A | 105 ft |
| Little Lac Courte Oreilles Lake | Sawyer | WI | A | 46 ft |
| Grindstone Lake | Sawyer | WI | A | 60 ft |
| Wind Lake | Polk | WI | B | 7 ft |
| Green Lake | Walworth | WI | B | 57 ft |
| Green Lake | Washington | WI | B | 37 ft |
| Potter Lake | Walworth | WI | B | 26 ft |
| Lake St Croix | St. Croix | WI | B | 60 ft |
| Spider Lake | Sawyer | WI | B | 64 ft |
| Spider Lake | Vilas | WI | B | 43 ft |
| Beaver Dam Lake | Barron | WI | B | 106 ft |
| Balsam Lake | Polk | WI | B | 37 ft |
| Silver Lake | Kenosha | WI | B | 44 ft |
| Silver Lake | Waushara | WI | B | 56 ft |
| Silver Lake | Waupaca | WI | B | 17 ft |
| Silver Lake | Columbia | WI | B | 42 ft |
| Silver Lake | Waushara | WI | B | 50 ft |
| Round Lake | Shawano | WI | B | 39 ft |
| Mirror Lake | Waupaca | WI | B | 43 ft |
| Deep Lake | Adams | WI | B | 49 ft |
| Beasley Lake | Waupaca | WI | B | 47 ft |
| Little Friess Lake | Washington | WI | B | 34 ft |
| Ashippun Lake | Waukesha | WI | B | 35 ft |
| Kusel Lake | Waushara | WI | B | 29 ft |
| Clear Lake | Rusk | WI | B | 74 ft |
| Clear Lake | Polk | WI | B | 26 ft |
| Rice Lake | Iron | WI | B | 21 ft |
| Bone Lake | Polk | WI | B | 43 ft |
| Marl Lake | Waushara | WI | B | 35 ft |
| Ottawa Lake | Waukesha | WI | B | 16 ft |
| Bear Lake | Barron | WI | B | 87 ft |
| Long Lake | Waupaca | WI | B | 76 ft |
| Long Lake | Fond du Lac | WI | B | 47 ft |
| Long Lake | Shawano | WI | B | 35 ft |
| Crooked Lake | Adams | WI | B | 56 ft |
| Crooked Lake | Oconto | WI | B | 37 ft |
| Wilke Lake | Manitowoc | WI | B | 21 ft |
| Rush Lake | Winnebago | WI | B | 5 ft |
| Lilly Lake | Kenosha | WI | B | 22 ft |
| East Alaska Lake | Kewaunee | WI | B | 50 ft |
| Rock Lake | Jefferson | WI | B | 60 ft |
| Pike Lake | Washington | WI | B | 45 ft |
Showing 50 of 420 infested lakes.
Frequently Asked Questions
How many lakes have curly-leaf pondweed?
Curly-Leaf Pondweed has been documented in 420 graded lakes: 420 in Wisconsin.
Does curly-leaf pondweed affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with curly-leaf pondweed should be monitored for changes in water quality over time.
Invasives Found With Curly-Leaf Pondweed
Co-occurs in 217 lakes · 494 total
Co-occurs in 180 lakes · 362 total
Co-occurs in 164 lakes · 275 total
Co-occurs in 131 lakes · 667 total
Co-occurs in 96 lakes · 247 total
Co-occurs in 36 lakes · 95 total
More on invasive species and lake health
Zebra mussel counts from the lakes LakeQuality grades, the counties that show up most often, and the Clean, Drain, Dry rules that still matter.
How lakes are graded A–F on nutrients and algae using EPA ecoregion condition classes, what each letter means in the water, and why an A is not a clearance.
Before you buy lakefront, check the water: clarity trend, nutrient impairment, algae advisories, invasive species, and depth — a data-backed checklist.
Source: EPA National Aquatic Resource Surveys, 2026.