Water availability indicator: data sources and methods, chapter 3

3. Data

3.1 Data source

Streamflow data used to calculate water supply were obtained from the Water Survey of Canada's HYDAT database. The HYDAT database includes average daily streamflow in cubic metres per second (m³/s) for a network of 2792 hydrometric stations across Canada. Water intake data were taken from three surveys: Statistics Canada's Industrial Water Use Survey 2009 and Agricultural Water Use Survey 2010 as well as Environment Canada's Municipal Water and Wastewater Survey 2009.

3.2 Spatial coverage

The Water Availability indicator is calculated for Canada's 164 sub-drainage areas (SDAs),^{Footnote [1]} excluding 22 sub-drainage areas in northern Canada.

3.3 Temporal coverage

The Water Availability indicator is calculated for 2009.

3.4 Data completeness

The data for some SDAs in Yukon, the Northwest Territories, Nunavut, Labrador and northern portions of British Columbia, Alberta, Saskatchewan, Manitoba and Ontario were merged because of low levels of human activity and the large surface-water supply in the rivers. The Okanagan Valley was evaluated at the sub-sub drainage area level. Northern Quebec was not evaluated due to a lack of available water flow data. The method used to calculate the Water Availability Indicator for some of the Arctic Ocean drainage areas could not be applied because of hydraulic regime (e.g., frozen streams) and extreme climate conditions.

3.5 Data timeliness

There is a time lag between 2009 (the year being reported on) and the publication of this indicator. This delay is due to several intertwining factors, including the time required to collect and verify the raw data; compile the data obtained from all partners at the national level; and analyze, review and report the data.