An Introduction to the Issues and the Ecosystems Lake Champlain Lake Champlain is the sixth largest inland waterbody in the United States, surpassed only by the Great Lakes. In the Lake Champlain Special Designation Act of 1990, Congress recognized its national significance.
South Lake is shallow with riverine characteristics.
It shows infestations of exotic Eurasian milfoil and water chestnuts, creating marshlike conditions. Broad Lake is relatively narrow, but contains deep water up to 400 feet. Malletts Bay lies to the southeast of Grand Isle near Burlington, Vermont, and displays a pattern of restricted circulation. Missisquoi Bay extends from the delta of the Missisquoi River north into the province of Quebec. Like the South Lake, it is shallow with luxuriant growths of water plants accentuating its marshlike qualities.