Vancouver Lake is located just west of Vancouver, Washington, United States, north of the Columbia River and Portland, Oregon, south of Ridgefield, Washington, and the Ridgefield National Wildlife Refuge. The lake is shallow, with a maximum depth of and a mean depth of less than. There is an island in the northern half of the lake named Turtle Island. The island was formed from the tailings of an Army Corps of Engineersdredging project, which dredged around the perimeter of the lake in the early 1980s. Lake River flowsfrom the north shore to the Columbia River near Ridgefield. Due to seasonal variation in relative river and lake levels, Lake River experiences intermittent flow reversal and flows into Vancouver Lake for considerable periods of time. The sources for Vancouver Lake's water include a flushing channel from the Columbia River near the southwest shoreline and Burnt Bridge Creek on the eastern shoreline, which winds about through many of the city's residential areas. Until the 1980s this creek was neglected and a major source of pollution for the lake. Lower River Road leads west out of Vancouver to a park on the shore of Vancouver Lake which includes a large swimming area. A trail leads to Frenchman's Bar Park on the nearby Columbia River.
Vancouver Lake was referenced in Lewis and Clark's journal entries from November 4th, 1805 . Shortly after the lake was deeded to the Port of Vancouver, Washington, in 1919, agricultural interests proposed draining it, but by the end of the 1920s, recreational uses were also considered. Because of cold weather, the lake was frozen solid to "several inches" in depth on February 10, 1929, and was home to 500 ice skaters one weekend. The lake was briefly considered as a decommissioning harbor in 1945, but after the Memorial Day flood of 1948 was also seen as a possible resource in flood control. Suburbanization of its watershed area led to an increase in water pollution. Surface runoff brought increased sediment while residential drain fields and increased use of fertilizers rich in nitrogen and phosphorus contributed to eutrophication. DDT was also used for mosquito control until its effects on fish and birds became apparent, and the county discontinued it. A 2005 report showed higher than normal levels of various contaminants in the lake's fish. Since then there have been various interests in the area as it relates to habitat preservation, recreation and industry, culminating in the "Habitek" plan of the mid-1980s and the multi-agency Burnt Bridge Creek Watershed Plan of 1995. Algal bloom has been an intermittent problem for recreational use of the lake since cyanobacteria such as Anabaena, Microcystis aeruginosa and Cylindrospermopsin raciborskii may produce neurotoxins such as cylindrospermopsin. The Vancouver Lake Watershed Partnership was formed in October 2004, bringing various public agencies with interest and jurisdiction together. Vancouver Lake plays host to two water sport oriented recreation clubs. Vancouver Lake Crew is a high school and master aged rowing club that uses the lake as its primary practice facility. Along with rowing, kayaking, canoeing, and dragon boating are also popular activities hosted by Vancouver Lake Crew. On the opposite shore sits the Vancouver Lake Sailing Club where sail boats can be launched.