In-stream, or non-consumptive water uses are uses that, for the most part, do not consume water, as the water is not removed from its natural environment. While in-stream uses cannot be measured quantitatively, those uses are described in terms of the characteristics of the water, or by the benefits they provide for people and the ecosystem. And while many don’t, some in-stream uses can alter or damage water quality. Factors such as flow rates and water levels are important for in-stream uses. The construction of a barrier, such as a hydroelectric dam, will alter the natural processes of the stream flow, particularly the highly productive ecosystems of deltas, estuaries and wetlands. Using water for human needs requires careful assessment and balance of the effects of those uses.
The main in-stream uses are:
- Ecosystem requirements, including flora, fauna, freshwater fish and waterfowl all rely on healthy water sources and habitat, including creeks, lakes, ponds, wetlands, marshes and estuaries for their survival. While some species live predominately in or on water, and others, such as the ultimate Canadian symbol, the beaver, require easy access to water, none could survive without clean freshwater. Scientists however, are just beginning to understand how nature itself requires a minimum quantity of freshwater in order to maintain and regenerate the very systems that produce and store freshwater in the first place.
- Hydroelectric power generation is currently the primary source of electricity in Canada, supplying about 62 per cent of the country’s electricity needs. The production capacity of this energy depends on two main factors – the available flow of water and the height from which that water drops. Dams are built to contain large quantities of water, which once held behind that barrier, accumulates potential energy. When the water is allowed to rush down the sluice, it strikes the rotary blades of the turbine, creating mechanical energy. The rotation of the turbine spins electromagnets, which generate current in stationary coils of wire. The current is then passed through a transformer which increases the voltage for long-distance transmission over power lines. While the water is not removed from the ecosystem, nor is it chemically altered through the process, the construction of dams permanently alters the natural ecosystem functions above and below the dam, often causing significant damage to the quality of life for people and animals living in those regions.
- Transportation via Canada’s waterways has historically been and continues to be an indispensible means of moving bulky raw materials, such as wheat, lumber, pulp and minerals. In the east, the main transportation waterway is the St. Lawrence River. The Mackenzie River provides a vital route for northern Canada, and the lower Fraser River in B.C. is a valuable corridor to the Pacific Ocean. With hundreds of millions of tonnes transported along these routes annually, reliable and predictable water levels are a key factor in determining the size and schedule of the vessels travelling on them. In the far north of the Yukon, Northwest Territories and Nunavut, ice roads are build on frozen waterways, providing transportation corridors during the winter months that connect remote communities.
- Freshwater fisheries contributed approximately $78 million to Canada’s GDP in 2002, employing about 3,600 people. In 2001, trout farming alone in Canada’s freshwater amounted to more than 6,500 tonnes of fish worth about $32 million. With its plentiful rivers and lakes, many of them in spectacular wilderness settings, Canada also attracts sport fishermen from around the world. In 2000, 3.6 million adult anglers, including Canadians and international visitors, spent about $6.7 million on fishing activities. In addition to human activities, Canada’s coastal rivers, such as those in B.C., provide spawning grounds for salmon and other fish species which support large saltwater fisheries.
- Recreation is a fundamental use of water in its liquid and solid forms for many Canadians. Water-based recreation also generates millions to the Canadian economy every year. From playing hockey on frozen ponds to Montreal’s Bell Centre to skating on Ottawa’s Rideau Canal, ice is central to Canadians’ very identity. From the freestyle mogul runs of Quebec’s ski resorts to the steep and deep powder of the interior B.C. backcountry, birthplace of the helicopter skiing industry, Canadians flock to ski slopes across the country. More than a thousand established and accessible waterfall ice climbs draw the world’s top ice climbers to the Canadian Rockies every winter. While some head to Vancouver Island to enjoy surfing, sea kayaking or whale watching, others sail the Great Lakes or relax on iceberg viewing cruises off the coast of Newfoundland and Labrador. During the summer months, more than a third of Canadian adults enjoy warm water activities, including sunbathing and beach lounging, water skiing, canoeing, fishing and whitewater rafting. Even camping, sightseeing and photography are pursued in places where lakes, rivers and waterfalls comprise a major attraction.
- Waste disposal is unfortunately a convenient and inexpensive use of waterways around the world for both human and industrial waste. While through history many viewed using water as a convenient receiving body for a myriad of unwanted substances, time and science have taught us that such a practice is not sustainable. While rivers and lakes are capable of absorbing and even flushing a certain amount of waste material, toxic chemicals and other foreign substances can create long-term damage to the ecosystem and human health. Eutrophication is the result of a lake becoming so rich in nutritive compounds, particularly nitrogen and phosphorus, that algae and other microscopic plant life become superabundant, causing the lake to evolve into a bog or marsh. Eventually the lake is choked and dries up. While eutrophication can occur naturally, the process is accelerated by the discharge of nutrients in the form of sewage, detergents and fertilizers into the ecosystem. Diligent monitoring and continuous application of control measures and penalties on behalf of municipal, regional and federal governments around the world are essential to combat this plague.
This piece allows users to select from various archival photos and illustrations, to learn more about the use of water by Canadians throughout history. Each image is supported with a narrated description.
On the next page:
The answer to the question is
You can find more about this
What is Canada's largest river?