Vancouver Lake 1960
History of Vancouver Lake
Vancouver Lake, located in Clark County near Vancouver, Washington, is a relatively large (approximately 2,600 acres) and shallow (mean depth 3–5 ft) lake that has recreational, environmental, and aesthetic value to the local community. It is the largest lake of the historical Columbia River floodplain lakes, and it is the largest lake in the wider Portland/Vancouver metropolitan area. In the late 1800s, the lake was much deeper (20 ft in some places) with clear waters (Bhagat and Orsborn, 1971).
Historically, the lake was connected to the Columbia River and degradation of water quality began shortly after flood control structures for the Columbia River were constructed, which severed the connection to ‘flushing’ water. Nutrient and sediment loading has increased over time, and hypoxia (low dissolved oxygen concentrations) and harmful algae blooms containing cyanobacteria in the lake led to poor water quality as early as the 1960s.
The first detailed water-quality study of the lake took place in 1967–68 by scientists at Washington State University (Bhagat and Orsborn, 1971). This early work was undertaken to assess how water quality would change if the hydrological characteristics of the lake were altered by the addition of a ‘flushing channel’ that would reconnect the lake directly to the Columbia River. The hope was that restoring this connection would decrease residence times in the lake and promote better flushing that would address water-quality issues. In the early 1980s, the flushing channel was completed.
The project included a large dredging operation, which formed a small island in the lake. Vancouver Lake is now hydrologically connected to the Columbia River by Lake River to the north, and by the Flushing Channel in the southwest. Compared to previous work, nutrient concentrations in the lake have declined, but high sediment loads are still a problem and the lake still experiences water-quality problems. Source: USGS 2010-2012.