A. Comprehensive data tables
B. Equivalences—units of measure
1 ha = 10,000 m2
100 ha = 1,000,000 m2 = 1 km2
1 km3 = 1,000,000,000 m3
1 L = 0.001 m3
Amount of water yield, runoff, evapotranspiration
1 mm (depth) is equivalent to 0.001 m3/m2 = 1 L/m2 = 10,000 L/ha
Abstraction: defined as the amount of water that is removed from any source, either permanently or temporarily, in a given period of time.Note 1 Wastewater discharged becomes available for re-abstraction downstream. The System of Environmental–Economic Accounting (SEEA) focuses on the inland water system, although sea or ocean water abstracted for production or consumption is included. It covers water used for the purpose of production and consumption activities and includes abstraction of soil water by plants and water used for hydro-electric-generation.
Aquatic ecosystem: An ecosystem is a community of interacting organisms and its physical environment. Aquatic ecosystems are located in a body of water. Subsets include marine and freshwater ecosystems. The latter include ecosystems in lakes, ponds, rivers, streams, wetlands and floodplains.
Aquifer: geological formation of permeable rock or material such as sand or gravel capable of holding significant quantities of water.
Biome: complex biotic community covering a large geographic area and characterized by the distinctive lifeforms of dominant species of plants and animals that are adapted to the particular conditions of the region.
Climate regions: Environment and Climate Change Canada presents climate trends and variations data for 11 climate regions across the country: Arctic Mountains and Fiords; Arctic Tundra; Atlantic Canada; Great Lakes/St. Lawrence; Mackenzie District; Northeastern Forest; Northwestern Forest; Pacific Coast; Prairies; South British Columbia Mountains and Yukon/North British Columbia Mountains. See Map 2.1 Canadian climatic regions in Statistics Canada, 2011, Human Activity and the Environment: Detailed Statistics, Catalogue no. 16-201-S.
Drainage regions: Statistics Canada groups 974 sub-sub-drainage areas representing all land and interior freshwater bodies into 25 drainage regions (Map 1.1). These drainage regions can be further grouped according to their outflow into one of 5 ocean drainage areas: the Pacific Ocean, Arctic Ocean, Gulf of Mexico, Hudson Bay or Atlantic Ocean. This geography is a variant of Statistics Canada’s official classification of drainage areas, the Standard Drainage Area Classification (SDAC) 2003.
Ecosystem functions: the biological, geochemical and physical processes that take place within an ecosystem.
Effluent: water or wastewater discharge from a treatment plant or industrial process.
Evapotranspiration: combined processes by which water is transferred from the earth’s surface to the atmosphere by evaporation from the land and ocean surfaces and by transpiration from vegetation.
Freshwater: water having a low concentration of dissolved salts.
Groundwater: water located below ground between particles of soil and fractured rock in the saturated zone below the water table (see for comparison soil moisture).
Groundwater discharge: the release of groundwater from the saturated zone. Depending on the characteristics of the aquifer including the permeability and porosity of confining rocks, groundwater flows slowly from recharge areas to discharge areas at springs, streams, lakes, wetlands and oceans. Groundwater discharge is a major contributor to the flow of streams and rivers.
Groundwater recharge: inflow of water from the surface into the saturated zone of the ground.
Hydrological cycle: the natural cycle in which water evaporates from the earth’s surface including the oceans to the atmosphere and returns to the earth as precipitation (see also water cycle).
Hydrometric data: data pertaining to the flow of water.
Instream flows: the amount of flowing water in a stream channel. Instream flow requirements refer to the amount of water needed in a stream to sustain ecological functions, aquatic habitat and water quality, as well as other instream water uses such as recreation or navigation.
Peatlands: organic wetlands, which contain accumulations of partially decayed plant matter. They include bogs, fens and swamps and are typically found in the north.
Permafrost: soil or rock in arctic, subarctic or alpine regions at variable depth beneath the earth’s surface in which a temperature below freezing has existed continuously for at least two years.
Phosphorus-source (P-source): the estimated amount of dissolved phosphorous potentially released from agricultural soils (mg/kg) in a census year. The P-source dataset provides information on the relative risk of phosphorus release and is produced as part of Agriculture and Agri-Food Canada’s Agri-environmental indicators. It is based on a function of cumulative phosphorus additions and removals over a 35-year period (1976 to 2011) and the degree of soil P saturation. P-source by itself does not estimate the risk of water contamination, which is dependent on both the P-source and a transport hydrology function.
Precipitation: water, in either liquid or solid form, that falls to the earth’s surface from the atmosphere. For example, rain, snow, hail or freezing rain.
Primary energy: Primary energy refers to energy in its naturally-occurring form (e.g., coal, crude oil, natural gas, primary electricity [hydro and nuclear] before conversion to end-use forms [e.g., refined petroleum products, secondary electricity]).
Renewable freshwater: refers to the water that regularly replenishes our rivers, lakes and aquifers. Non-renewable freshwater describes water that is stored in deep aquifers, ice caps and glaciers that have a negligible rate of recharge on a human time scale. Some freshwater in the Great Lakes and other major water bodies can also be considered non-renewable since the renewal rates are very low.
Residual soil nitrogen (RSN): the amount of nitrogen remaining in agriculture soils (kg/ha) in a given year after accounting for atmospheric deposition, nitrogen fixation, crop inputs (fertilizer and manure), crop removals (harvesting) and gaseous losses of ammonia, nitrous oxide and nitrogen gas. The RSN dataset produced as part of Agriculture and Agri-Food Canada’s Agri-Environmental Indicator dataset provides a calculation of the amount of nitrogen in the top 60 cm of the soil at the end of the cropping season for Canadian agricultural lands. RSN by itself does not estimate the risk of water contamination. Surplus nitrogen can remain in the soil and be used by subsequent crops or it can be lost to the environment.
Runoff: the portion of precipitation and melt from snowpack and glaciers that, by a variety of paths above and below the surface of the ground, reaches the stream channel. Once it enters a stream channel, runoff becomes streamflow.
Saturated zone: the region below the water table that is saturated with water. This water is called groundwater.
Soil moisture: water located in the unsaturated zone above the water table but below the surface of the earth (see for comparison groundwater).
Thermal electric power generation: refers to power generation that uses a fuel source (e.g., fossil fuels or nuclear energy) to produce heat or steam, with which to generate electricity.
Turbidity: a measure of the relative clarity or cloudiness of a liquid, caused by suspended particles (e.g. clay, silt, metals, organic matter, microorganisms), and measured in nephelometric turbidity units (NTU).
Unregulated flow: refers to natural streamflow, as opposed to controlled releases of water, in a stream or river. In a regulated river, downstream flows are regulated based on releases from a major storage or dam. Unregulated flows can occur in regulated rivers.
Unsaturated zone: subsurface zone above the water table that contains both air and soil moisture.
Wastewater discharge: refers to water that is returned to the environment in its liquid state, usually close to an industrial establishment. Discharged water may be treated or untreated.
Water cycle: the natural cycle in which water evaporates from the earth’s surface including the oceans to the atmosphere and returns to the earth as precipitation (see also hydrological cycle).
Water intake: the amount of water extracted from water bodies (see also water withdrawal).
Water quality: term used to describe the physical, chemical and biological characteristics of water. These characteristics can include temperature, turbidity, pH, dissolved solids, metals, oxygen, total coliforms, e. coli, and other parameters. Water quality is normally considered in relation to its suitability for a specific use.
Water use: Water use is the amount of water withdrawn from water resources to support society in both the economic and residential sectors. Water withdrawals are also referred to as water intake. Water use estimates included in this report include water loss and leakages through water treatment and distribution systems. They exclude the use of water for hydro-electricity production.
Water withdrawal: the amount of water extracted from water bodies (see also water intake).
Water yield: is an estimate of freshwater runoff into streams and rivers and provides information on Canada’s renewable freshwater supply. It is derived from data on the unregulated flow of water in rivers and streams in Canada. Although the water yield provides an estimate of renewable freshwater, it can include some water that is considered non-renewable (e.g., melt water from receding glaciers).
D. Summary of methodology for water yield and the intake to yield ratio map
Water yield methodology
Estimates of the monthly and annual water yield for Canada, southern Canada, and for the 25 drainage regions, covering the 1971 to 2013 period, are produced by Statistics Canada. These data are part of the Environmental Accounting Program and, along with other measures of natural capital such as land, timber, minerals, energy and greenhouse gas emissions, provide time series data on elements of the environment following the United Nation’s statistical standard System of Environmental–Economic Accounting.Note 2 These estimates of renewable freshwater for Canada are produced using a peer-reviewed, approach and are updated regularly.
The main purpose of these estimates is to provide measures of the stock of renewable freshwater in Canada and its drainage regions, in and by themselves useful measures to track through time, but also useful denominators against which to analyze the flows of water to and from the economy such as abstraction and discharge by industry and households.
The estimates may also be used for other purposes; however, users should be aware of data limitations in instances where finer resolution or more precise data may be required.
The water yield estimates are derived from monthly volumes of unregulated flows in Canada’s rivers and streams. A database of natural streamflow data was compiled and combined with upstream basin delineations for each of the gauging stations from which observations were taken. These data cover the 1971 to 2013 time period. Streamflow values were converted to a runoff depth, geo-located at the basin centroid and then interpolated using a geospatial estimation method (ordinary kriging) to create spatial estimates of runoff. These spatial estimates were summed at the drainage region level to create various regional and temporal estimates over a 42-year period.
The methodology and results were validated using several techniques to understand the uncertainty of the estimates. For example, the data were compared against other estimates and streamflow observations and various types of analysis were performed.
Results and limitations
Results were included in this study where reasonable validation was possible. Generally, results were included where data points were denser, as seen for example in southern Canada; where mean standard error was lower; and where validation results were good.
Results were not included where uncertainty was too high as indicated by the mean standard error or a declining data density, as seen for example in many northern areas; where further validation is required because insufficient data was available for comparison; where the spatial arrangement of stations had changed over time; or where the scale was finer than what the model was originally intended to support. Few northern results were included because northern networks are sparsely populated, with fewer stations available across larger distances.
Nationally, the number of stations gradually increased from 1971 to the late 1980s when station density peaked. The number of stations then declined to their lowest level by the late 1990s, with the steepest drop in 1993 and 1994. The overall number of stations has since remained relatively constant. Many individual drainage regions follow a similar pattern, with the exception of some drainage regions in the southern areas of the country where more consistent station densities were maintained since 1971.
For a more comprehensive review of the methodology including validation steps please refer to: Statistics Canada, 2009, “The Water Yield for Canada as a Thirty-year Average (1971 to 2000): Concepts, Methodology and Initial Results,” Environment Accounts and Statistics Analytical and Technical Paper Series, Catalogue no. 16-001-M, no. 7.
Intake to water yield ratio map
The surface freshwater intake to water yield ratio map highlights a number of important regional relationships between the supply of and demand for surface freshwater in Canada. The indicator map divides the total surface water intake of manufacturing, mining, thermal-electric power generation, agriculture and drinking water plants by the renewable freshwater supplied (water yield) for the month of August, a month with a higher potential for stress. The results provide insight on broad regional issues such as potential pressure on the availability and accessibility of the resource, stress on aquatic ecosystems reliant on appropriate flows, and economic value of the services provided by the resource.
Consumptive use and water supplied by non-renewable water sources in some lakes and other water stocks are not the focus of this indicator. However, these issues are also important aspects to consider when assessing the supply-demand relationship.
Surface freshwater intake sums the water use data from the Survey of Drinking Water Plants, 2013 and Industrial Water Use Survey, 2013, with estimates of agricultural water use for 2013 based on various years of the Agricultural Water Use Survey and Alberta Irrigation Information report. Withdrawals performed by the upstream oil and gas industry, as well as withdrawals from groundwater, groundwater under the influence of surface water and marine waters are excluded from the calculations.
E. Additional information for drainage region profile maps and land cover and land use categories
Maps included in the drainage region profiles in Section 3 were produced by Statistics Canada, Environment, Energy and Transportation Statistics Division. Complete reference and background information is as follows:
Land use maps
The main data source for the land use class information is: Agriculture and Agri-Food Canada (AAFC), 2015, Land Use, 2010, (accessed September 16, 2015).
- Built-up area is based on classes 21 (Settlement) and 25 (Roads).
- Agricultural land use is based on classes 51 (Cropland) and 61 (Managed grasslands). Note that the sources used for the agricultural land use classes shown on the maps differ from those used to produce the arable and natural land for pasture statistics in the tables and charts, which are based on data from the Interpolated Census of Agriculture.
- Natural and semi-natural area is the residual area remaining after subtracting built-up and agricultural land use areas from the total area.
Water is taken from: Natural Resources Canada (NRCan), Canada Centre for Mapping and Earth Observation (CCMEO), 2014, CanVec+, (accessed August 10, 2015).
For northern areas outside the agricultural ecumene, land use data has been supplemented using: NRCan, 2009, Land cover, Circa 2000–Vector, Earth Sciences Sector, (accessed December 15, 2016).
In addition, the built-up areas for these northern regions were estimated using data from Statistics Canada’s road network files and Settlements program: Statistics Canada, 2011, Road Network File, 2011 Census, Catalogue no. 92-500-X; Statistics Canada, “Introducing a new concept and methodology for delineating settlement boundaries: A research project on Canadian settlements,” Environment Accounts and Statistics Analytical and Technical Paper Series, Catalogue no. 16-001-M, no. 11.
Additional reference information for the maps (e.g., US boundaries and digital elevation models) come from United States Census Bureau, 2014, States, Cartographic boundary shapefile: cb _2014_us_state _500k.zip, (accessed October 29, 2015); Danielson, J.J. and D.B Gesch, 2011, Global multi-resolution terrain elevation data 2010 (GMTED2010): U.S. Geological Survey Open-File Report 2011-1073, 26p.
Land cover and land use charts and tables
These statistics are based on the methodology developed for Human Activity and the Environment, 2015 (Appendix B – Data sources and methods)
- Built-up area is based on classes 21 (Settlement) and 25 (Roads) from AAFC Land Use, 2010.
- Arable land is composed of the cropland, tame or seeded pasture and summerfallow land from the Interpolated Census of Agriculture.
- Natural land for pasture is taken from the Interpolated Census of Agriculture.
- Natural and semi-natural land is the residual area remaining after subtracting built-up area, arable land and natural land for pasture from the total area.