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

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.

Watercourses are line features - natural or manmade - that represent the location of flowing surface water. This product requires the use of geographic information system (GIS) software.

Delimitation of protective areas for surface drinking water withdrawals forThe territory of the City of Rouyn-Noranda**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

The North America Surface Water Values point dataset contains the current water level and stream flow values as recorded by Canadian and USA hydrometric gauging station locations. Daily values are recorded as well as comparisons with historical measurements, including difference in values from the previous day, the mean level for that calendar date, the annual mean water level, and maximum and minumum recorded levels. Percentile values based on historical average for both water level and stream flow are also included.Real-time gauging station data for Canada is available here: https://wateroffice.ec.gc.ca/search/statistics_e.htmlReal-time gauging station data for the United States is available here: https://waterservices.usgs.gov/rest/Statistics-Service.html

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.

This theme represents an indicator of the availability of summer and winter surface water. It combines a sub-indicator of the pressure of water samples from surface water, and a sub-indicator of the severity of low water levels. The indicator is calculated based on the current and future climate.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

A shapefile of the Nova Scotia Automated Surface Water Quality Monitoring Network monitoring stations. The network was established in 2002 to assess near real-time water quality in surface waters across the province at five river stations and one lake station. The results are used to help manage water resources, determine baseline water quality in lakes and watercourses throughout the province, evaluate the impact of human activities on surface water, and assess long term trends in water quality. The following weblink connects to a Nova Scotia Department of Environment and Climate Change web map that includes the six monitoring station locations and an alternative method for downloading the same dataset: http://nse.maps.arcgis.com/apps/webappviewer/index.html?id=7ded7a30bef44f848e8a4fc8672c89bd

Digitization of long-term water chemistry data collected between 1920's - 1990's from lakes across Saskatchewan by the Saskatchewan Fisheries Research Laboratory. Samples were collected using methods from the Standard Methods for the Examination of Water and Wastewater (APHA, AWWA and WPCF). This data serves as a baseline for water quality.This dataset is a digitization from paper records of water chemistry data across Saskatchewan collected by the Saskatchewan Fisheries Research Laboratory. Data ranges from the 1920's to the 1990's and were sampled using methodes from the Standard Methods for the Examination of Water and Wastewater (American Public Health Association, American Water Works Association and Water Pollution Control Facility) This long-term water chemistry data serves as a baseline for water quality. Different variables of water chemistry are organized into individual fields. The units of measurement appear at the end of each field name. Due to the historical nature of the data some uncertainty exist in values.  Additonal notes on data: ND: no detection Trace: trace amounts Nil: zero NA: no data