Canada’s landmass contains approximately 20% of the world’s total freshwater resources, or about 7% of the global renewable freshwater supply. Canada has a relatively small population in proportion to our share of global renewable freshwater, and like many countries, has challenges associated with water quality and availability. Protecting and responsibly managing our water resources is of critical importance to ensure it remains available and safe to use, now and in the future.
Depending on the region, annual water flows in rivers, lakes, wetlands and aquifers can vary. This can lead to issues like flooding and droughts. The following are examples of factors that can influence water quantity:
- Weather variability: Changes in the amount of precipitation from year to year, can result in changes to snow, ice and permafrost, which directly affect the water supply.
- Climate change: Increased temperatures, beyond historic variability, can lead to earlier winter snow melt, resulting in higher flows in early spring and less water that is available in the summer.
- Industry and infrastructure: Industry can require high volumes of water to operate processing facilities and infrastructure such as dams, can result in changes to how water naturally flows.
- Urbanization: Cities remove natural vegetation cover and wetlands and replace them with surfaces that water cannot penetrate (for example, roads or parking lots). This changes water dynamics, including groundwater recharge, soil moisture, erosion and runoff.
Did You Know?
Spanning the Canada – U.S. border in the mid-east region of North America, the Great Lakes are freshwater lakes that cover 244,106 km² (double the area of New Brunswick and Nova Scotia together). They play a vital role for our environment, economy, and climate as they represent:
- an important source of biodiversity, providing a home to over 3,500 species;
- a key source of economic income and growth, representing 1.5 million jobs and $60 billion in wages; and
- a means of regulating local and regional weather patterns.
The Great Lakes Nearshore Waters Assessment was undertaken by Government of Canada researchers with the Province of Ontario, U.S. partners and academia. The assessment provides data on water quality, coastal processes, ecosystems, and advisories on human use from government and non-government organizations to assess the overall state of the environment and the potential effects on human health.
Water quality refers to the condition of the water. This includes whether it is safe for drinking, capable of supporting healthy ecosystems or suitable for other purposes like recreation.
Water quality is influenced by the physical, biological and chemical properties of water. Examples of properties that can be monitored include temperature, bacteria concentration and pollution levels present in water, which can interact and influence one another.
The following are examples of factors that can influence water quality:
- Atmospheric deposition, where gas or solid substances present in the air dissolve, are absorbed by, or mix with rain and are deposited on land and in waterbodies;
- Surface leaching, where substances on the earth’s surfaces (e.g. contaminated soil and ore-rich rocks) dissolve in rain and runoff into bodies of water;
- Urban runoff, where harmful substances on roads and in open areas are picked up through rainfall and are deposited into bodies of water;
- Industrial, farming, mining, forestry and waste management activities that directly or indirectly deposit wastewater into bodies of water; and
- Wastewater and ballast water discharge from ships, where harmful substances enter the marine environment.
Individually, each one of these factors may pose low risk to water quantity and quality, but when combined, their cumulative effects can bring increased risk of ecological, human health, social and economic effects.
Assessing the health of freshwater ecosystems and water quality monitoring in Canada
The map below shows examples of the data available through the Open Science and Data Platform. The first dataset is “Water Quality Indicators in Canadian Rivers”, which provides data from water quality monitoring stations in rivers across Canada. At each monitoring station, water quality data are compared to water quality guidelines to create a rating for the site.
The “Maps of Reporting Facilities – Total Releases to Water” dataset highlights all facilities that report direct releases to surface waters through the National Pollutant Release Inventory. The data shows the combined total of substances released by reporting facilities in tonnes per year.