When it rains, debris, oil, trash, litter, soot, grease, and pesticides that once covered the roads, sidewalks, rooftops and lawns have not just vanished - they have been washed away, into the sewers, through underground pipes, into a nearby lake, river, or bay. This occurrence is referred to as urban stormwater runoff which Environment Canada calls a "significant environmental detriment". Stormwater runoff occurs when it rains, when snow melts, or when any form of precipitation comes into contact with the ground or any other hard surface.
Through the natural cycle of water, precipitation should seep into the ground, get absorbed by soil and vegetation, and evaporate back into the atmosphere. However, as a result of mass development in urban areas, stormwater can no longer reach the soil, and instead runs off hard surfaces (such as buildings, sidewalks, and roads) into storm sewers, taking with it any contaminants in its path. The result is polluted water resources, which in turn affects public health, recreation, biodiversity, economic activity, and general public well-being.
Many of us contribute to polluted urban runoff, often without realizing it. Follow these simple steps to reduce the amount of pollutants that enter our waters and help maintain the natural water cycle.