Water withdrawal and consumption by sector indicator: data sources and methods, chapter 3

3. Data

3.1 Data source

Data for water withdrawal in 2005, 2007, 2009, 2011 and 2013 by the thermal power generation, manufacturing, households, agriculture, commercial and institutional, mining, and oil and gas sectors are taken from two Statistics Canada tables: Water use in Canada by sector and Physical flow account for water use.^{Footnote [1]},^{Footnote [2]} These tables summarize results from the Industrial Water Survey (IWS),^{Footnote [3]} Agricultural Water Survey (AWS),^{Footnote [4]} Survey of Drinking Water Plants (SDWP)^{Footnote [5]} and Environment Canada's Municipal Water and Wastewater Survey (MWWS).^{Footnote [6]} Data for the seven economic sectors reported in the indicator summarize data from 91 industrial activities classified by Statistics Canada (see Annex A).

The water consumption figures for the thermal power generation, manufacturing and mining sectors are taken directly from the IWS. For the agriculture sector, the factor used to estimate water consumption for 2005, 2007, 2009 and 2011 was obtained from Agriculture and Agri-Food Canada scientists in the Prairie/Boreal Plain Ecozone region. For 2013, the consumption factor was based on a return rate from water use for irrigation in Alberta and applied across the country.^{Footnote [7]} For the households sector, estimates of water consumption were obtained from Environment Canada's MWWS. For the oil and gas sector, estimates of consumption were based on water recycling rates from the Government of Alberta's Oil Sands - Water website.

3.2 Spatial coverage

The IWS includes all Canadian thermal-electric power generating stations. It also samples mines and manufacturing locations across Canada.

The AWS samples Canadian farm operations that irrigate.

The MWWS ended in 2011, with data up to 2009, and surveyed all Canadian municipalities with a population over 1000 and a sample of those with population under 1000 (excluding federal lands and First Nations communities).

The SDWP replaces data from the MWWS and reports data for 2011 and 2013 from drinking water treatment plants across Canada that serve 300 or more people and that are licensed and regulated by provincial/territorial agencies (excluding First Nations communities).

3.3 Temporal coverage

Survey results from the IWS, AWS and MWWS since 2005 and from the SDWP since 2011 have been included in this indicator.

3.4 Data completeness

Water withdrawal and consumption estimates for the thermal power generation, manufacturing and mining sectors were taken from the IWS. The response rate for the thermal-electric component of the IWS was 88% in 2013, 90% in 2011, 84% in 2009, 92% in 2007, and 88% in 2005. For the manufacturing component of the IWS, the response rate was 64% in 2013,^{Footnote [8]} 62% in 2011,^{Footnote [9]} 70% in 2009,^{Footnote [10]} 72% in 2007,^{Footnote [11]} and 70% in 2005.^{Footnote [12]} The response rate for the mining component was 75% in 2013,^{Footnote [3]} 65% in 2011,^{Footnote [9]} 79% in 2009 and 2007, and 70% in 2005.

Statistics Canada used the AWS to calculate estimates of water withdrawal for agriculture. The response rate for the AWS was 74.3% in 2014,^{Footnote [13]} 75.5% in 2012,^{Footnote [14]} and 57% in 2010.^{Footnote [15]} The 2014 AWS excludes a variety of agricultural practices, such as reserve farms, community pastures, pure hatcheries, and farms producing Christmas trees. Farms with sales of less than $10 000 are also excluded, as are those that reported owning irrigation equipment but did not report any irrigation areas. The seven northernmost drainage regions are also excluded. Imputation was used to deduce the response for a missing or inconsistent field when partial information was available. The 2014 AWS sampled 7937 Canadian farm operations that irrigate.

Water withdrawal estimates for the households and commercial and institutional sectors were based on data from the MWWS and SDWP. Response rates for the MWWS varied by survey year and question. In the 2009 MWWS, residential water service data were available for a responding population of 28 884 690 Canadians. In 2006, residential water service data were available for 28 177 339 Canadians, and, in 2004, the responding population represented 25 454 421 Canadians.^{Footnote [16]}

The SDWP is a census of drinking water plants serving 300 or more people. Treatment plants are asked to report information on volumes of water treated, type of treatment, financial aspects of the operation, as well as the quality of the raw water used as a source for the plant. The survey excludes systems that supply water to communities with less than 300 people and other regulated systems that service schools, camp grounds, commercial establishments, provincial parks, etc. Approximately 2000 drinking water facilities were included in the 2013 SDWP.

Consumption estimates for the households, commercial and institutional, agriculture, and oil and gas sectors were calculated using factors applied to withdrawal estimates from government reports or scientific opinion. Refer to the Methods section for a complete explanation.

3.5 Data timeliness

This indicator uses the most recent survey data available. The IWS is conducted every two years with the most recent results published in October 2015.^{Footnote [3]} The AWS is also conducted every two years; the most recent results were published in September 2015.^{Footnote [4]} The most recent results for the SDWP, conducted every two years, were published in June 2015.^{Footnote [5]} The MWWS was conducted every two to three years from the early 1980s to 2009, with data released approximately two years after the calendar year to which the collected data applied.^{Footnote [16]}