Columbia Lake is a lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 near Portage

Portage, Wisconsin

Portage is a city in and the county seat of Columbia County, Wisconsin, United States. The population was 10,662 at the 2010 census making it the largest city in Columbia County...

 in Columbia County, Wisconsin

Columbia County, Wisconsin

-Unincorporated communities:*Anacker*Belle Fountain*Durwards Glen*East Friesland*Harmony Grove*Ingle*Keyeser*Lake Wisconsin*Leeds*Lowville*Marcellon*North Leeds*Okee*Otsego-External links:***...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is fed by the Wisconsin River and receives warm water discharged from a nearby power plant. As a result, the portion of the lake to the west of a dividing bank of earth is 70 to 85 °F or circa 20 to 30 °C year round, with a dense cover of fog in colder weather. This temperature prevents many types of lake weeds from growing. The lake is stocked with various types of fish and contains an uncommon hybrid bass. Four pacus, a South American fish similar to the piranha

Piranha

A piranha or piraña is a member of family Characidae in order Characiformes, an omnivorous freshwater fish that inhabits South American rivers. In Venezuela, they are called caribes...

, which were thrown into the lake survived until they were caught and removed from the lake.