Understanding The Watershed

Streams and Rivers

Historically, streams and rivers have been our lifeblood. However, over the years development along rivers and some streams has produced some adverse side effects:

  • Channelization and dams have altered habitats for aquatic and terrestrial life, resulting in the loss of important species.
  • Loss of shoreline vegetation has caused increases in water temperature, destroying the habitat of some fish species and aquatic vegetation.
  • Erosion of fine sediment into waterbodies has destroyed important fish habitat.
  • Toxic materials discharged into rivers and streams also pass through the food chain to either humans or wildlife.

In the past, protection of our rivers and streams has focused on single discharges (point sources) from industrial facilities or municipal water/septic treatment plants. We now need to broaden our focus to include nonpoint sources, which represent an equal or perhaps greater threat to our rivers. Controlling these sources will require changing the way we live.

Lake Simcoe

Lake Simcoe is a valuable natural resource and a critical component of the natural environment. The primary threat to the health of the lake is changing land use. This has led to an increase in the amount of phosphorus and sediment running off the land and into Lake Simcoe. Changing land use, rapid urban growth and human activities that occur in the Lake Simcoe watershed has caused the lake to change.

The change, in biological terms, is called eutrophication. This is a natural process that involves the addition of nutrients, specifically phosphorus, which promote increased plant growth in the lake. Under natural conditions, this is a slow, complex process, but agricultural activities and increased urban growth within the drainage basin has accelerated this process in Lake Simcoe. When a lake becomes eutrophic, it receives excessive plant nutrients and supports heavy plant growth, and the deep cold water of the lake has a reduced level of dissolved oxygen. All this results in the deterioration of water quality and the loss of a naturally reproducing cold water fishery.

It is not too late to correct these problems. By reducing phosphorus input from man-made sources, the eutrophication process can be slowed. If the level of phosphorus entering Lake Simcoe is reduced, algae blooms and weed growth will decrease, water quality will improve and a more stable fishery with a naturally reproducing population of lake trout and lake whitefish will exist.

Wetlands

Approximately seven percent of the Lake Simcoe watershed is covered by wetlands. Wetlands have many natural and cultural values, they:

  • Are important for the control and storage of surface water and groundwater.
  • Maintain and improve water quality, aid in flood control and protect shorelines from erosion.
  • Trap sediment and nutrients that would otherwise fill water courses and eventually Lake Simcoe.
  • Provide important habitat for many plant and animal species.
  • Support and initiate complex food chains.
  • Help maintain water quality in adjacent watercourses that support populations of fish.
  • Provide active and passive recreational opportunities.
  • Provide educational and research opportunities.

Loss of wetland function and value can be attributed to nonpoint source activities in upland areas immediately next to wetlands, such as housing, industrial development, and landfills. Pollution may not completely destroy a wetland, but it may seriously impair its quality as habitat or its ability to perform vital functions. For example, the discharge of septic effluent or stormwater into or over wetlands may have adverse effects on productivity and pose human health risks. Other land use activities, such as the creation of landfills, have affected wetlands, both directly by filling them in and indirectly by leaking of toxic or hazardous materials from landfills into adjacent wetland.

Under the authority of the Planning Act, the Province of Ontario issued the Provincial Policy Statement in 1997 to provide policy direction on matters of provincial interest related to land use planning and development. The policies focus on the key provincial interests related to land use planning. Section 2.3 Natural Heritage, gives direction to municipalities, planning boards, public agencies, the private sector and others for the protection of all natural heritage features including wetlands. The goal of the policy statement is to ensure that wetlands are protected from incompatible development.