More than 150 bird species use the Don as a migration route each year. The ravine systems in Toronto are especially important. Toronto lies in the overlapping zones of the two major North American migratory flyways, the Atlantic and the Mississippi. The number of migratory birds using the Don Valley as a green corridor is three times greater than the number of birds that actually nest in the Don. It is critical that we protect these green corridors from becoming fragmented by development, and ensure that proper resting and feeding habitats are available.
Many people assume that poor water quality in the Don River is the result of industrial pollutants.
This is not accurate. As it makes its way from hard surfaces to the sewer system and into the Don River, stormwater absorbs and carries pollutants like rust fragments, road salt, anti-freeze, and gasoline. The impact of these pollutants on flora and fauna is dramatic. In downtown areas of Toronto, stormwater mixes with sanitary sewage in older, undersized sewers which overflow when they reach capacity during rain storms. This overflow, which is more polluted than pure stormwater, dumps into the stormwater sewer system and into the Don River.