National Hydrometric Program

The National Hydrometric Program is responsible for collecting, interpreting and disseminating standardized information about surface water availability (quantity). Environment Canada’s Water Survey of Canada (WSC) operates most of the 2 800 hydrometric stations in Canada on behalf of most provinces and all territories, under federal-provincial and federal-territorial agreements. In Quebec, the province collects its water quantity information on behalf of the Government of Canada under a similar agreement.

Hydrometric means, “related to the measurement of velocity, discharge, volume and other physical parameters of surface waters and surface water bodies.” There are three main facets of the Water Survey of Canada’s work:

  • measure water levels and velocities
  • estimate and analyze flow (or discharge)
  • publish hydrometric data.

Our technicians monitor levels and flows of Canadian waters within its mandate and assesses conditions and trends. In turn, this knowledge is used for such purposes as climate change research, fisheries management, flood forecasting, floodplain management, water quality monitoring, hydro-power production, navigation, engineering design and recreational needs. The information is also used for water policy purposes by federal, provincial and municipal governments.

How hydrometric monitoring is done

The WSC uses state-of-the-art monitoring equipment and methods to collect and process the hydrometric data.

At each station, water level data are recorded continuously in digital form using an automated electronic recorder, or "data logger".

A hydrometric technologist visits the station periodically to take measurements of water depth and velocity, which are required to determine the rate of flow, or discharge, of the river. The technologist takes these measurements from a bridge, by wading in a stream, by boat, or using a cableway strung across a river.

Once a relationship between water level and flow (discharge) has been established, flow data are routinely estimated from the recorded water level data.

In the office, the WSC technologists review and finalize the data under a rigorous quality management process (ISO 9001). The data are stored in the national database and disseminated to users via the web. 

While all stations record data on site, currently about two thirds of the stations on the hydrometric network transmit data to users via the Internet in real time, using either satellite or telephone communications systems. Daily decisions about the operation of dams and reservoirs depend on this real-time data. Flood forecasting centres and hydropower companies also rely on this data to prepare accurate and up-to-date forecasts.

Benefits to Canadians

Environment Canada’s science and technology provides valuable information that helps us to protect and conserve our water supplies.

We all need water for drinking, cooking and washing. Almost every sector of our economy needs accurate information about Canada’s water supplies for planning, economic and social development, operational purposes and to ensure environmental sustainability. For example, water is essential for agricultural industries, as a source of hydroelectric energy, for transportation, and recreation and tourism. Water information is also critical to ensure the safety of Canadians by supporting flood prediction and drought monitoring activities.

Internet resources

Information about Environment Canada’s Hydrometric Program and the Water Survey of Canada

Learn about the interesting freshwater science happening at Environment Canada’s Canada Centre for Inland Waters and meet some of the people doing the research

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