Streams, and their associated floodplains and upland areas, are a vital watershed resource of great economic, cultural, and environmental value. Streams and floodplains perform a number of ecological functions, such as controlling water flow, storing water, removing harmful pollutants from water, and providing habitat for plants and animals, including fish. These habitats tend to support a large number of species, and have a high rate of biological productivity, making them key components of the living landscape.
There are four major stream systems out-letting to Lake Ontario within the CLOCA jurisdiction.
From west to east, they are: Lynde Creek, Oshawa Creek, Black, Harmony, Farewell Creek, and Bowmanville/Soper Creek. There are also numerous smaller drainages, including Pringle Creek, Corbett Creek, Robinson Creek, Tooley Creek and Westside Creek.
The major stream systems in the jurisdiction contain some of the last cold water trout habitats in the Greater Toronto Area. Brook trout, rainbow trout, brown trout, Chinook salmon, and coho salmon are all found within the streams of CLOCA’s jurisdiction, as well as many other interesting fish species. Some of the stream systems outlet to coastal wetlands, providing diverse habitats for wetland and lake species as well, such as northern pike, black crappie, walleye and bass.
Redside dace are also found in some of the stream systems. This species has been listed as Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). This means that redside dace have characteristics that make them particularly sensitive to human activities or natural events, which puts the species at risk.