The sources for Vancouver Lake's water include a flushing channel (equipped with tidal gates to control flows) from the Columbia River near the southwest shoreline and Burnt Bridge Creek on the eastern shoreline, which winds about ten miles (sixteen kilometres) through many of the city's residential areas.

A study published in 2014 by Curt D.Peterson, et al, PSU Dept of Geology, includes results from multiple core samples which demonstrate there's been a lake in this location continuously going back at least 4000 years.

Current turbidity, more shallow depths and a lack of aquatic plant structures have diminished the variety of species and more recent surveys showed the most abundant fish by mass were brown bullhead, white crappie, black crappie, and common carp, with a few juvenile salmonids and a population of channel catfish, largemouth bass, bluegill, pumpkinseed, yellow perch, naturalized goldfish, northern pikeminnow, American shad, mosquito fish, largescale sucker, and freshwater sculpin.

[5][6] Rich fringe environments provide habitat for amphibians such as tree frogs, reptiles such as garter snakes and a wide variety of birds, including large species such as great blue herons, osprey and bald eagles.

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.

[10][11] The Vancouver Lake Watershed Partnership was formed in October 2004, bringing various public agencies with interest and jurisdiction together.

Along with rowing, kayaking, canoeing, and dragon boating are also popular activities hosted by Vancouver Lake Crew.