Analysis of Canada's water use: tracing water flow from source to end use

Freshwater is a critical natural resource and fundamental to social and environmental activities, including industrial activities, food production, and residential needs. Hence, it is important to understand provincial water supply and demand. However, there are large gaps in provincial and sectoral water use data. This study provides estimates for disaggregated water use by regional subsectors and uses Sankey diagrams to depict the water flow from intake to consumption and discharge. The study uses a bottom-up method in the oil and gas and hydropower sectors and top-down methods in the residential, commercial and institutional, manufacturing, mining, agricultural, and power sectors. Surface and ground water are considered separately. Water use in the year 2017 was analyzed for British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, the Atlantic Provinces, and the Territories. Water-use intensities were also calculated by region and sector. A total of 40 billion m(3) of water use is traced from source to either discharge or consumption. New disaggregated data is developed provincially and by sector for oil and gas, mining, and power generation. Water use in the oil and gas sector was disaggregated into 5 subsectors, with oil sands surface mining in Alberta as the largest consumer with 138 million m(3) of water consumed. Hydro power was estimated to consume the most water out of all sectors, with 3393 million m(3) of water consumed. Alberta was also found to have the largest consumptive water use per capita. The results provide important insights on water supply and demand in Canada. Such information supports both regional and federal governments in formulating appropriate regional and sectoral policies and can support water managers and the public in understanding water supply and demand in Canada. Modelling efforts requiring regional and sectoral water use can also use these results.