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The Importance of Surface Water Data


"Accurate information on the condition and trends of a country's water resource--surface and groundwater; quantity and quality--is required as a basis for economic and social development, and for maintenance of environmental quality through a proper perception of the physical processes controlling the hydrological cycle in time and space.... almost every sector of a nation's economy has some requirement for water information, for planning, development, or operational purposes."
--WMO/UNESCO Report on Water Resources Assessment, p. 16.

Canada has 7% of the world's renewable water. It seems that we have more than our fair share. But this fact is misleading: about 60 percent of Canada's fresh water drains to the north, while 85 percent of the population lives within 300 kilometres of our southern border. In other words, much of our water is not where it is needed most, in the heavily populated areas. And even in areas where water is plentiful, it is fast becoming polluted and unusable. In addition, there is periodic drought in certain regions, such as the Prairies. In fact, Canada is not as rich in water as it seems: water may very well become the issue in this century that energy was in the last.

Canada's water supply not only has limits, it also has many competing uses. The need for drinking, cooking, washing, and other domestic uses is obvious, but water is also essential to the pulp and paper and agricultural industries; it is a source of hydroelectric energy; it serves as a medium of transportation, as a recreational and tourism base, and as an aesthetic asset of which many Canadian communities are proud. The continued availability of surface water is an essential ingredient of Canada's future development.

With so many competing uses and a finite amount of water, we need to manage it in the best possible way, so that there is enough water, and of sufficient quality, for everyone. To make sound decisions we need reliable data. The box below summarizes the people involved in water management and indicates their needs for data.

We can use water without depleting its supply. But water is a fundamental component of a complex ecosystem - its maximum sustainable yield depends on how we exploit it within the system. Evidence of overexploitation and environmental stress is abundant. Pollution from human activities destroys aquatic life and threatens human health. Misuse of the water resource causes widespread degradation of soils, disrupts the supply of potable water, and generates massive economic losses. To be aware of the extent of these problems and to manage them, we need baseline data.

Being such a large country, Canada covers many different geographical regions. As a result, the hydrologic characteristics vary significantly across the land, as shown in Figure 2. Water and environmental issues are directly related to the hydrologic and socioeconomic conditions of each region. The management of those issues therefore requires an understanding of the regional hydrology. Measurements are the only reliable indicator of the status and trends of the available surface water across the country and as such are essential for making decisions that concern water.

As pressures on our water increase, the need for reliable hydrologic data and information becomes more urgent. The data collected by Environment Canada and its partners make it possible to manage this vital resource and the environment that it nourishes.

Principal Uses of Hydrometric Data in Canada

  • Aquatic Ecosystem Research
  • Climate Change Research
  • Environmental Impact Studies
  • Fisheries Management
  • Flood Forecasting
  • Floodplain Management
  • Forest Management
  • Hydro-Electric Power Generation
  • Infrastructure planning and design
  • Interjurisdictional Water Apportionment
  • International Relations
  • Irrigation and Drainage
  • Operation of Dams and Reservoirs
  • Recreation (e.g. boating)
  • Regional resource inventories
  • Regional water management
  • Sediment Studies
  • Transportation/navigation
  • Water quality studies
  • Water Resource Assessment/inventory
  • Water Resources Research
  • Water supply studies
  • Watershed studies

Sustainable Development

"The overall objective of the federal water policy is to encourage the use of freshwater in an efficient and equitable manner consistent with the social, economic, and environmental needs of present and future generations."
--Federal Water Policy, Environment Canada.

It is becoming clear that we must not only manage water as carefully as any other valuable resource, but we must also keep it unimpaired for future generations. We must not endanger the natural systems that support life on earth - the atmosphere, the waters, the soils and other living beings.

This is the concept of sustainable development, increasingly viewed as the essential management philosophy for all our environment and resources. Endorsed by Canadian environmentalists, business leaders, and government officials, this concept is now being incorporated in water resource programs and activities across the country. To manage water in a sustainable way, we need to:

  • develop a better understanding of the physical, chemical, and biological components of aquatic systems;
  • improve our knowledge about how atmospheric and terrestrial changes impact on water; and
  • apply this knowledge appropriately to anticipate and prevent environmental degradation from occurring.

The challenge for water data collection programs of all types will be to ensure that the data and information produced contribute to the achievement of these three objectives as fully as possible.

Who Needs Surface Water Data and Why?

Water Management -- Federal and provincial government agencies, control boards and conservation authorities, and private and public hydropower agencies all use water data to operate discharge structures, to control reservoir levels, to divert water into irrigation canals, and to control town water supply withdrawals and sewage discharge. These activities have serious and far-reaching financial and social implications, and should be based on the best possible data and information. Flow forecasting is a major use of water level and streamflow data, enabling maximum hydroelectric power generation and flood warning and protection.

Planning -- Scientific, engineering, and planning professionals use streamflow and sediment data to analyze problems, project future conditions, determine impacts, assess alternatives, and set policy for planning of a variety of large-scale water and other resource projects.

Environmental Assessment -- Environmental consultants and interest groups often need surface-water and sediment data and information; while some require only a general indication of water availability in an area, others need precise records to assess critical concentrations of pollutants and toxic chemicals.

Research -- Professionals and scientists engaged in water-related research use water data as the basis of understanding fundamental hydrologic relationships and water balance. This research is vital to Canada's long-term interests and cannot be carried out using approximations: high quality, accurate information is essential. Research into evaporation processes, for example, is important in water-short Prairie regions, and research into ice problems is necessary for flood hazard reduction programs throughout the country. And the potential impacts of climate change on water supplies need to be understood so that appropriate changes can be made in water management.

Government -- Many of the federal government's responsibilities depend on accurate surface water and sediment data for proper execution. For example, activities associated with fisheries, forestry, navigation, international relations, agriculture, federal lands, sovereignty, and apportionment all rely on water data and information. In fact, the Federal Water Policy lists 25 issues of national concern, and surface water data play a basic role in addressing all but one of these. Provincial governments, as the actual owners and stewards of the resource, operate programs such as irrigation, pollution control, and licensing that are even more dependent on surface water data.

International -- The exchange of water-related and technology data between countries helps their water agencies to accurately determine the effects of meteorological and land-base disturbances; to make technological improvements to their individual data-gathering methods and systems; to facilitate discussion of events and advances by having comparable measurements; and to allocate water, when necessary, between the countries.

Public Uses -- Many private citizens and citizens' groups want access to water-related information for a wide range of situations, from planning recreational activities to preventing property damage caused by erosion or flooding. General information on the state of a region's surface water conditions, as well as site-specific data, are extremely important to this client group.

Design and Construction -- Professional engineers must have accurate water data for a variety of hydraulic design projects such as dams, reservoirs, pipelines, and canals. Safety during project construction, and economic performance during their lifespan, are important criteria for these clients, clients, who depend on site-specific data, supplemented by regional information, to meet their needs.

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