Human Activity and the Environment 2016
Freshwater in Canada
Human Activity and the Environment 2016: Freshwater in Canada provides up-to-date statistics on freshwater supply and demand and includes maps, charts and tables for each of Canada’s 25 drainage regions. The following bullets present selected highlights from the report:
- Canada is rich in freshwater resources. It has the third largest renewable freshwater supply worldwide and the second largest amount per capita among developed countries, at 103,899 m3 per person.
- The average annual water yieldNote 1 for Canada from 1971 to 2013 was 3,478 km3 or 0.349 m3/m2, equivalent to a depth of 349 mm across the extent of the country.
- The annual water yield in southern Canada fluctuated over time, from a high of 1,544 km3 in 1974 to a low of 1,165 km3 in 1987. The water yield decreased from 1971 to 1987 and then began a gradual recovery to 2012, with a dip in the late 1990s to early 2000s.
- The Pacific Coastal drainage region in British Columbia had the highest water yield per unit area in the country at 1.5 m3/m2. The lowest yields were found in the Missouri, Assiniboine–Red, South Saskatchewan and North Saskatchewan drainage regions in the Prairies, which had an average annual water yield per unit area of 0.05 m3/m2.
- Water yield varies throughout the year, with the highest flows generally in spring and early summer. The median monthly water yield for southern Canada from 1971 to 2013 peaked at 218 km3 in May, but dropped to 76 km3 in August, with a low of 50 km3 in February.
- Water yields in the Okanagan–Similkameen and the Assiniboine–Red drainage regions are the most heavily dominated by spring flows—in these areas the median water yields for April, May and June accounted for 75% and 77% respectively of the annual flows over the 1971 to 2013 period. In contrast, the peak median water yields occurred later in the year and declined more gradually in the South and North Saskatchewan drainage regions.
- In 2013, monthly maximum turbidity values for surface water sources were highest in the Lower Saskatchewan–Nelson, North Saskatchewan and Assiniboine–Red drainage regions in the Prairies and in the St. Lawrence drainage region, while the lowest levels were seen in drainage regions in British Columbia and the Atlantic provinces.
- In 2013, water withdrawals for economic and household activities totaled 37,892 million m3 (37.9 km3). Industry or households withdrew 87% of this water directly from rivers, lakes and groundwater, while the remainder was supplied by drinking water plants. Although some of this water was consumed—for example, lost to evaporation, transpiration or included in products—the majority was returned back to the environment after use.
- The main water users in 2013 were electric power generation, transmission and distribution (68%); manufacturing (10%); households (9%); agriculture (5%) and mining and oil and gas extraction (3%).
- Total household water use was 3,239 million m3 in 2013, down 16% compared to 3,875 million m3 in 2005, while on a per capita basis water use has dropped from approximately 330 L/person/day to 250 L/person/day.
- Looking at water use from the final demand perspective, which attributes water use related to the production of goods and services to the end-user of that product rather than to the producer, households were responsible for 53% of total water use in 2013, followed by the production of goods and services for export at 30%.
- Challenges in balancing water supplies to water demand tend to peak in late summer. The highest surface water intake to water yield ratios for August 2013 occurred in the Assiniboine–Red and in the Great Lakes drainage regions, followed by the South Saskatchewan and Okanagan–Similkameen. Higher intake to yield ratios point to a higher possibility for water shortages, conflicts between competing uses and the potential for insufficient instream flows for ecosystem requirements.