A drainage basin is an area that drains all precipitation received as a runoff or base flow (groundwater sources) into a particular river or set of rivers. Canada’s major drainage regions are the Atlantic Ocean, Hudson Bay, Arctic Ocean, Pacific Ocean and Gulf of Mexico. Rivers are organized into networks, each with its own recharge area upstream, and drainage channel and mouth downstream. Networks are ordered from ocean to main river to secondary rivers to streams which correspond to ocean basins, river basins, sub-basins, sub-sub-basins, and so forth. The boundary of a watershed is called a drainage divide.

This map shows the five ocean drainage areas in Canada, the major river basins, the internal drainage areas and the diverted drainage areas. A drainage basin, sometimes called a watershed, is an area where all surface water shares the same drainage outlet. Surface water consists of the tiny trickles of water flowing on the surface of the earth that develop into larger streams and eventually combine to form a river. The boundary of a watershed is called a drainage divide.

Contained within the 2nd Edition (1915) of the Atlas of Canada is a map that shows the delineation of drainage basin. The total area drained is indicated in square miles for each basin, and drainage basins of the principal river systems of Canada, along with their areas. This includes the great oceanic drainage basins and the Hudson Bay basin. Only the Canadian drainage area is indicated on the map for basins that lie partly in the United States. There is also a table listing the lengths of major rivers in Canada and their principal tributaries.

Contained within the 1st Edition (1906) of the Atlas of Canada is a map that shows the delineation of drainage basins. The geographic extent of each drainage basin is delineated and the total area drained for each basin is provided in square miles. This includes the great oceanic drainage basin and the Hudson Bay basin. Only the Canadian drainage area is indicated on the map for basins that lie partly in the United States. There is also a table listing the lengths of major rivers of Canada and their principal tributaries.

This dataset consists of drainage basin boundaries for selected transboundary basins draining to the Gulf of Alaska in south-east Alaska. Basins were delineated to the basin outlet using a tidal datum of mean high water (MHW). The drainage basins are provided as polygons attributed with basin drainage area and as polylines attributed with the data source for each line segment, respectively.

Contained within the 5th Edition (1978 to 1995) of the National Atlas of Canada is a map that shows ocean drainage areas with component river basins and diversion areas. There are two tables: one gives data on drainage basin areas, the other on major drainage diversions.

Major Drainage Areas (MDA), as portrayed in this map, are part of the Standard Drainage Area Classification (SDAC) which was developed by Natural Resources Canada, in partnership with Statistics Canada, and Environment and Climate Change Canada. A drainage area, as opposed to a drainage basin or watershed, is a unit of statistical aggregation used for reporting purposes based upon drainage patterns and the underlying basins, delimited by a drainage divide. A drainage basin, sometimes called a watershed, is an area where all surface water shares the same drainage outlet. Surface water consists of water flowing on the surface of the earth that develops into larger streams and eventually combines to form a river. The 11 MDAs presented in this map comprise the uppermost level in the drainage area classification system which then divides into 164 sub-drainage areas, and then is further divided into 974 sub-sub-drainage areas. Relief was derived from the merging of two raster data sets, both resampled to 804 metre resolution: - High Resolution Digital Elevation Model (HRDEM) – CanElevation Series - Canadian Digital Elevation Model, 1945-2011 Further information on all these maps can be found on the Atlas of Canada web site atlas.gc.ca.

A drainage basin is an area that drains all precipitation received as a runoff or base flow (groundwater sources) into a particular river or set of rivers. Canada’s major drainage regions are the Atlantic Ocean, Hudson Bay, Arctic Ocean, Pacific Ocean and Gulf of Mexico. Rivers are organized into networks, each with its own recharge area upstream, and drainage channel and mouth downstream. Networks are ordered from ocean to main river to secondary rivers to streams which correspond to ocean basins, river basins, sub-basins, sub-sub-basins, and so forth. The boundary of a watershed is called a drainage divide.

Contained within the 2nd Edition (1915) of the Atlas of Canada is a map that shows the delineation of drainage basin. The total area drained is indicated in square miles for each basin, and drainage basins of the principal river systems of Canada, along with their areas. This includes the great oceanic drainage basins and the Hudson Bay basin. Only the Canadian drainage area is indicated on the map for basins that lie partly in the United States. There is also a table listing the lengths of major rivers in Canada and their principal tributaries.

A drainage basin is the area that drains all precipitation into a river or stream system into a common outlet such as a lake or sea. There are two main river basins in Nunavut: the Thelon River flows into Hudson Bay and the Back River empties into the Arctic Ocean. Most of Nunavut’s area is not drained through large rivers; instead the water flows directly to the ocean through small rivers and streams.

Contained within the 5th Edition (1978 to 1995) of the National Atlas of Canada is a map that shows ocean drainage areas with component river basins and diversion areas. There are two tables: one gives data on drainage basin areas, the other on major drainage diversions.

The Red River Basin: The International Joint Commission (IJC) of Canada and the United States developed this Esri Web Map Series to provide a structured geographic overview of shared drainage basins that span the Canada-U.S. border. This series was specifically designed to be incorporated into a General Esri Story Map that serves as an introduction to transboundary watersheds, highlighting their geographic, environmental, and hydrological significance.Purpose and UseThe Web Map Series is intended to:Offer a general introduction to shared drainage basins along the Canada-U.S. boundary.Provide a consistent spatial reference for transboundary water governance and policy discussions.Serve as a foundational dataset for broader studies on hydrology, environmental management, and cross-border cooperation.Core Features of the Web Map SeriesThe features included in each Web Map vary by basin but generally include the following:Harmonized Drainage BasinsBased on datasets from the United States Geological Survey (USGS) and Environment and Climate Change Canada (ECCC).Provides a unified representation of drainage basins across the international boundary.Indigenous Communities (as interpreted by federal agencies)Displays Indigenous communities based on datasets from Canadian and U.S. federal agencies.This layer does not represent traditional or historical lands, but rather current federally recognized Indigenous lands.Water Level GaugesIncludes real-time and historical water level monitoring stations.Provides hydrological data critical for flood forecasting, drought assessment, and water resource management.Major Hydrological FeaturesDams and Diversions – Identifies hydropower facilities, flood control structures, and major water diversions impacting shared basins.Rivers and Lakes – Highlights significant hydrologic networks that define transboundary watersheds.Populated Places and Place NamesIncludes official municipalities, towns, and cities within and near the basin boundaries.Features official geographic place names from federal, state, and provincial authorities.Protected AreasDisplays Federal, State, and Provincial Parks within transboundary basins.Highlights protected lands relevant to watershed conservation and ecological management.Significance of the Web Map SeriesThe IJC Web Map Series is designed to serve as a foundational geographic tool for decision-makers, researchers, and the public to better understand the shared hydrological systems of Canada and the United States. By integrating authoritative datasets from both countries, this Web Map Series promotes a standardized approach to visualizing transboundary watersheds, supporting cooperative water resource management and policy development.Important Note: The representation of Indigenous or First Nation lands in this Web Map Series does not indicate traditional or historical territories; rather, it reflects data provided by federal agencies in Canada and the United States.This Web Map Series will continue to evolve as new datasets become available, ensuring that transboundary water governance is supported with the most up-to-date and authoritative geographic information.

Drainage basins of Manitoba. Hydrologic drainage basins found within Manitoba. The Assiniboine River basin is divided to indicate the Shellmouth Reservoir subbasin, to better illustrate local impacts and conditions. Basin names are in English and French.

This Esri Group Layer presents the U.S. Army Corps of Engineers (USACE) National Inventory of Dams (NID) dataset, spatially clipped to the drainage basins that cross the Canada–United States international boundary.The National Inventory of Dams (NID) is the authoritative, federally maintained database of U.S. dams that meet defined criteria. A dam is included in the NID if it is:At least 25 feet (7.6 meters) high with a storage capacity greater than 15 acre-feet (18,500 cubic meters), orHas a storage capacity greater than 50 acre-feet (61,600 cubic meters) regardless of height, orPoses a significant or high hazard potential, regardless of size.The NID includes comprehensive attribute data on dam location, type, size, purpose, ownership, regulatory information, and hazard classification. It is a critical national dataset for infrastructure management, water resources planning, public safety, and environmental assessment.By clipping the dataset to transboundary basins shared by the U.S. and Canada, this Group Layer supports the International Joint Commission (IJC) and its Boards in cross-border water management. It highlights dams with potential influence on binational rivers, lakes, and watersheds, facilitating integrated planning for flood control, water supply, hydropower, recreation, and ecosystem management.This Group Layer is intended to serve as a fundamental reference layer for IJC StoryMaps, Dashboards, and Atlas applications, enabling comparison with Canadian dam and water infrastructure datasets where available.

This hosted feature layer displays the shared harmonized basins andsubbasins for the Souris River as coordinated by the International Joint Commission (IJC) in collaboration with Environment and Climate Change Canada (ECCC), the United States Geological Survey (USGS), Natural Resources Canada (NRCan), and Agriculture and Agri-Foods Canada (AAFC). It also includes drainage delineations from respective states and provinces.This feature layer provides an authoritative representation of the harmonized basins and subbasindelineations for the Souris River, shared by Canada-U.S., created through a collaborative effort between federal and regional agencies. The layer consists of polygons representing the harmonized delineations of HUC 3 (6-digit) basins and HUC 4 (8-digit) subbasins based on the U.S. Watershed Boundary Dataset (WBD) and corresponding Canadian datasets. These delineations have been aligned with federal, state, and provincial interpretations to ensure consistency and accuracy across the international boundary. The dataset supports the management and coordination of water resources and aligns with the IJC’s mandate to promote collaborative water management between Canada and the United States.

Contained within the 1st Edition (1906) of the Atlas of Canada is a map that shows the delineation of drainage basins. The geographic extent of each drainage basin is delineated and the total area drained for each basin is provided in square miles. This includes the great oceanic drainage basin and the Hudson Bay basin. Only the Canadian drainage area is indicated on the map for basins that lie partly in the United States. There is also a table listing the lengths of major rivers of Canada and their principal tributaries.

GIS representation of the WSA Major Drainage Basins. These are watershed boundaries that were derived using Agriculture and Agri-Food Canada's Watershed Project watershed boundaries. The full AAFC Watersheds dataset can be downloaded from here: https://open.canada.ca/data/en/dataset/c20d97e7-60d8-4df8-8611-4d499a796493

The Ontario Watershed Boundaries (OWB) collection represents the authoritative watershed boundaries for Ontario. The data is based on a framework similar to the Atlas of Canada Fundamental Drainage Areas and the United States Watershed Boundary Dataset, however it adopts a more stringent scientific approach to watershed delineation. The Ontario Watershed Boundaries (OWB) collection includes five data classes:OWB Main (OWB) (Download: Shapefile | File Geodatabase | Open Data Service | QGIS Layer )all watershed levels from primary to quaternary, and level 5 and 6 watersheds for select areas of the province;OWB Primary (OWBPRIM) (Download: SHP | FGDB | ODS | QLR-Diverted Flow | QLR-Natural Flow)all primary watersheds or major drainage areas (WSCMDA) in the Canadian classification;OWB Secondary (OWBSEC) (Download: SHP | FGDB | ODS | QLR*)all secondary watersheds or sub drainage areas (WSCSDA);OWB Tertiary (OWBTERT) (Download: SHP | FGDB | ODS | QLR*)all tertiary watersheds or sub-sub drainage areas (WSCSSDA);OWB Quaternary (OWBQUAT) (Download: SHP | FGDB | ODS | QLR)all quaternary watersheds or 6-digit drainage areas (WSC6).*Display issues in QGIS are currently being investigated for these services. See the RSS feed below for details.IMPORTANT NOTE: The OWB data replaces the following data classes:Provincial Watersheds, HistoricalAdditional DocumentationUser Guide for Ontario Watershed Boundaries (Word)Watershed Delineation Principles and Guidelines for Ontario (Word) Atlas of Canada 1,000,000 National Frameworks Data, Hydrology - Fundamental Drainage Areas United States Geological Survey Watershed Boundary Dataset (Website)

Status Completed: Production of the data has been completed

Maintenance and Update Frequency Irregular: data is updated in intervals that are uneven in duration - usually after the completion of major updates to source data (e.g. OIH), but could also include spot updates and expansion of the dataset over time based on user needs. RSS FeedFollow our feed to get the latest announcements and developments concerning our watersheds. Visit our feed at the bottom of our ArcGIS Online OWB page.

Contact Ontario Ministry of Natural Resources - Geospatial Ontario, geospatial@ontario.ca

This hosted feature layer displays the shared harmonized basins and subbasins for the Winnipeg River as coordinated by the International Joint Commission (IJC) in collaboration with Environment and Climate Change Canada (ECCC), the United States Geological Survey (USGS), Natural Resources Canada (NRCan), and Agriculture and Agri-Foods Canada (AAFC). It also includes drainage delineations from respective states and provinces.This feature layer provides an authoritative representation of the harmonized basins and subbasin delineations for the Winnipeg River, shared by Canada-U.S., created through a collaborative effort between federal and regional agencies. The layer consists of polygons representing the harmonized delineations of HUC 3 (6-digit) basins and HUC 4 (8-digit) subbasins based on the U.S. Watershed Boundary Dataset (WBD) and corresponding Canadian datasets. These delineations have been aligned with federal, state, and provincial interpretations to ensure consistency and accuracy across the international boundary. The dataset supports the management and coordination of water resources and aligns with the IJC’s mandate to promote collaborative water management between Canada and the United States.

Summary of statistics, regression analyses, LOADEST regressions, mean annual flow-weighted concentrations/values, and Kendal tau trend analyses of flow-weighted constituent concentrations of dissolved chloride, suspended sediment, dissolved oxygen, pH, and Temperature values of water samples collected intermittently at USGS streamgages on the Canadian River or its tributaries from northeastern New Mexico, to Lake Eufaula in Oklahoma from 1949-2013. Water-quality data were retrieved from the USGS NWIS system in 2014.