Faucet Snail

Invasive SpeciesFound in 41 lakes

Faucet Snail appears on state infested-waters lists for 41 surface waters. Boaters and anglers moving gear in or out of those lakes carry a clean-drain-dry obligation under state law. 41 lakes — narrow enough that aggressive containment is still on the table. Most upper-Midwest invasives that established here did so quietly over a decade before anyone noticed, so a low number today is not a guarantee for tomorrow.

The presence of Faucet Snail 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.

Total Lakes

Minnesota

Wisconsin

Lakes with Faucet Snail

Lake	County	State	Grade	Depth
Long Lake	Hubbard	MN	A	135 ft
Lower Bottle Lake	Hubbard	MN	A	110 ft
George Lake	Hubbard	MN	A	29 ft
Upper Bottle Lake	Hubbard	MN	A	55 ft
Duck Lake	Hubbard	MN	A	23 ft
Fourth Crow Wing Lake	Hubbard	MN	A	10 ft
Boulder Lake	Hubbard	MN	A	28 ft
Teal Lake Deep	Cook	MN	A	-
Little Lake Deep	Cook	MN	A	-
Third Crow Wing Lake	Hubbard	MN	B	35 ft
Paddock Lake	Kenosha	WI	B	32 ft
Lower Phantom Lake	Waukesha	WI	B	12 ft
South Long Lake	Crow Wing	MN	C	47 ft
Upper Twin Lake	Hubbard	MN	C	12 ft
Blackduck Lake	Beltrami	MN	C	28 ft
Sugar Lake	Itasca	MN	C	22 ft
First Crow Wing Lake	Hubbard	MN	C	15 ft
Bowstring Lake	Itasca	MN	C	32 ft
Cut Foot Sioux Lake	Itasca	MN	C	-
Lake Winnibigoshish	Cass	MN	C	69.8 ft
Tamarack Bay Lake	Cass	MN	C	69.8 ft
Third River Flowage Lake	Itasca	MN	C	69.8 ft
Little Winnibigoshish Lake	Itasca	MN	C	28 ft
Shawano Lake	Shawano	WI	C	39.5 ft
Lower Twin Lake	Wadena	MN	D	26 ft
Stocking Lake	Wadena	MN	D	22 ft
Little Cut Foot Lake	Itasca	MN	D	20 ft
Knife Lake	Kanabec	MN	F	15 ft
Blackwater Lake	Itasca	MN	NR	72 ft
Little Lake Inlet	Cook	MN	NR	-
Little Lake Landing	Cook	MN	NR	-
Robinson Lake	Wabasha	MN	NR	-
Superior Lake	Cook	MN	NR	-
Superior Lake	St. Louis	MN	NR	-
Duluth Lake	St. Louis	MN	NR	-
Second Crow Wing Lake	Hubbard	MN	NR	35 ft
Teal Lake Landing	Cook	MN	NR	-
Little Lake Culvert	Cook	MN	NR	-
Lake Winneconne	Winnebago	WI	NR	9 ft
Lake Butte des Morts	Winnebago	WI	NR	9 ft
Lake Poygan	Winnebago	WI	NR	11 ft

Frequently Asked Questions

How many lakes have faucet snail?

Faucet Snail has been documented in 41 graded lakes: 35 in Minnesota, 6 in Wisconsin.

Does faucet snail affect water quality?

Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with faucet snail should be monitored for changes in water quality over time.

Invasives Found With Faucet Snail

Zebra Mussel

Co-occurs in 22 lakes · 667 total

Eurasian Watermilfoil

Co-occurs in 11 lakes · 849 total

New Zealand Mud Snail

Co-occurs in 9 lakes · 9 total

Round Goby

Co-occurs in 9 lakes · 18 total

Ruffe

Co-occurs in 9 lakes · 12 total

Spiny Waterflea

Co-occurs in 9 lakes · 78 total

More on invasive species and lake health

Zebra Mussel Spread: How Many Lakes Are Affected?

Zebra mussel counts from the lakes LakeQuality grades, the counties that show up most often, and the Clean, Drain, Dry rules that still matter.

Lake Water Quality Grades Explained: What A–F Means

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.

What to Check Before Buying Lakefront Property

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.