This product provides the ratio of surface freshwater intake to water yield for August 2013, with the exception of drainage regions 7, 8, 16, 17 and 18, which use the ratio of August intake to the long-term minimum monthly water yield. Surface freshwater intake aggregates data from the Survey of Drinking Water Plants, 2013 and the Industrial Water Use Survey, 2013 with estimates of agricultural water use for 2013 based on the Agricultural Water Use Survey and the Alberta Irrigation Information report. Data for water use by the oil and gas industry and households not supplied by a public water provider are also excluded.

This product provides the median of monthly maximum turbidity values (in nephelometric turbidity units) for drinking water facilities by drainage region. Turbidity refers to the relative cloudiness of water, caused by suspended particles in water. The Survey of Drinking Water Plants collected this monthly maximum turbidity data for surface water sources from facilities reporting turbidity data for at least 10 months in 2013. These facilities served 24 million people and produced 4,091 million cubic metres of potable water from surface water sources in 2013. Source water turbidity was monitored continuously at 42% of these drinking water plants in 2013, daily at 34% of plants and less frequently at the remaining plants.

This product provides the variability index for selected drainage regions in Canada. Variability is measured using a coefficient of variation (CV) to compare all months over a 42-year time period and is a measure of the dispersion or variation in the monthly yield values from 1971 to 2013 (and 1971 to 2012 for drainage region 1). It is defined as the ratio of the standard deviation to the mean or the standard deviation divided by the mean, with higher CVs indicating more variability in monthly water yields. The monthly variability was not calculated for drainage regions 5, 7, 8, 16, 17, 18, or the Labrador portion of 25.

Polygon features representing the geographical extent of a source area that contributes water to a drinking water system. A drinking water system is any domestic system servicing anything other than a single-family dwelling, as defined in the Drinking Water Protection Act. Source Area is a broad term used to describe any area that could potentially contribute water to the drinking water system; it does not mean that hydrologic analyses have been completed to determine likelihood of connectivity. These source areas most often represent the entire aquifer extent (for ground water systems) or the watershed upstream from the intake (for surface water systems). This is one of three Drinking Water Sources datasets (along with the DWS - Intakes/Wellheads points dataset, and DWS - Protection Zones polygons dataset). Note: these polygons have unique Source Areas IDs used to relate them to the Intakes/Wellhead points.

Province-wide spatial view showing licensed water sources (streams and lakes), under the Water Act, (current and historical), not captured (displayed) on TRIM base mapping (or Freshwater Atlas base mapping).

The locations of coastal ferry routes in British Columbia. This includes ferries in coastal waters like BC Ferries, barges, water taxis, etc. but does not include freshwater ferries on inland rivers or lakes.

Data represents surface water occurrence frequency (percentage), which describes the frequency for each grid appeared as water in the 30 years time period of 1991 to 2020. The data covers Canada’s entire landmass including all transboundary watersheds, and is at 30-meter spatial resolution. The surface water occurrence frequency is derived using the surface water model of Wang et al. (2023) from all-available monthly water data observed by the Landsat satellites (Pekel et al., 2016). Here, permanent waters are represented by 100%, and permanent land surfaces by 0%, of water occurrence for a 30-meter by 30-meter grid.References:Pekel, J.-F., A. Cottam, N. Gorelick, A.S. Belward, 2016, High-resolution mapping of global surface water and its long-term changes. Nature, 540, 418-422.Wang, S., J. Li, and H. A. J. Russell, 2023, Methods for Estimating Surface Water Storage Changes and Their Evaluations. Journal of Hydrometeorology, DOI: https://doi.org/10.1175/JHM-D-22-0098.1.

Data set includes the smaller areas of sensitivity (a standard radius around water intake points) and the larger areas of concern (determined by land, soil and water characteristics of the surrounding area).

Knowledge of the location of Earth’s surface water in time and space is critical to inform policy decisions on environment, wildlife, and human security. Dynamic surface water maps generally represent water occurrence, also referred to as inundation frequency, depicting the percentage of valid observations when water is detected at the surface. The location and duration of surface water varies from areas of permanent water with 100% inundation frequency where water is always observed, to areas of permanent land with 0% inundation where water never occurs. Between these two extremes are areas of ephemeral water that experience periodic flooding with inundation frequencies between 0-100%. National-scale dynamic surface water information was generated for years 1984-2023 at 30m spatial resolution from the historical Landsat archive over Canada. The complete dataset consists of annual water maps and derived products including inundation frequency and inter-annual wetting and drying trends calculated using per-pixel logistic regression. The complete dataset enables an assessment of the timing, duration, and trends towards wetting or drying at regional to national scales.Associated publication:https://www.sciencedirect.com/science/article/pii/S0034425722002358

Assessment Watersheds are mesoscale aquatic units designed to replace the 3rd order 1:50K watersheds. Assessment Watersheds are based on groupings of fundamental watersheds using FWA watershed code and local code, with a target size of between 2,000ha and 10,000ha.