Environment Canada's Great Lakes Clean-Up Fund has funded programs to reduce runoff and fence watercourses in the watersheds of Hamilton Harbour, Big Otter Creek, Wheatley Harbour, Detroit River, Severn Sound, Bay of Quinte, and the St. Lawrence River. The use of vegetated buffer zones around watercourses in urban and rural areas reduces the concentrations and loadings of nitrate entering the surface water through runoff by retaining the nitrate in soil and plants. Effective vegetated buffer strips can range from mixed woodlands to a strip of grass and can vary in size from a few metres in width to hundreds of metres. Examples of actual successes with vegetated buffer zones include a 24 metre grass buffer which reduced nitrate concentrations in water runoff from 10 ppm to below 1 ppm and a 19 metre mixed woodland buffer which reduced concentrations of nitrate from approximately 7 ppm to 0.5 ppm in the water that entered the stream. In addition to removing nitrates, buffers can improve shelter and spawning or nesting habitat for amphibians and birds.
Buffers can also reduce the amounts of phosphorous and sediments that enter watercourses.
This helps to keep oxygen levels high so that fish, such as trout and salmon, can survive. Forested buffers adjacent to mid-sized streams can moderate temperatures, stabilize banks, reduce erosion, and provide important sources of organic matter to stream communities. This keeps water courses clean and healthy for invertebrates, amphibians, birds, fish, and mammals. The habitat revegetated in one year. Peterjohn, W.T. and D.L. Correll.