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.

Note: This data has been replaced by the [Ontario Watershed Boundaries (OWB)](https://geohub.lio.gov.on.ca/datasets/mnrf::ontario-watershed-boundaries-owb). We are no longer updating this data. It is best suited for historical research and analysis. A watershed, also known as a catchment basin, includes all land that is drained by a watercourse and its tributaries. Watersheds are split into four categories: * primary * secondary * tertiary * quaternary These divisions are based on the federal framework originally known as the Water Resources Index Inventory Filing System. Ontario has 3 primary watersheds: * Great Lakes – St. Lawrence * Southwestern Hudson Bay * Nelson River Secondary watersheds are subdivisions of primary watersheds in Ontario. Most secondary divisions are either large river systems or groupings of small coastal streams. Tertiary watersheds are subdivisions of secondary watersheds in Ontario. Quaternary watersheds are subdivisions of tertiary watersheds. There are more than 1000 quaternary watersheds in Ontario.

Units dividing the Columbia Basin in to BC Hydro reservoir-based watersheds

This collection represents the authoritative watershed boundaries for Ontario. The data is based on a framework similar to the [Atlas of Canada Fundamental Drainage Areas](https://open.canada.ca/data/en/dataset/a4b190fe-e090-4e6d-881e-b87956c07977) and the [United States Watershed Boundary Dataset](https://www.usgs.gov/core-science-systems/ngp/national-hydrography/watershed-boundary-dataset?qt-science_support_page_related_con=4#qt-science_support_page_related_con), however it adopts a more stringent scientific approach to watershed delineation. The Ontario Watershed Boundaries (OWB) collection includes five data classes: * OWB main: all levels from primary to quaternary and 5th and 6th levels in select areas * OWB primary: all primary watersheds or major drainage areas in the Canadian classification * OWB secondary: all secondary watersheds or sub drainage areas * OWB tertiary: all tertiary watersheds or sub sub drainage areas * OWB quaternary: all quaternary watersheds or 6-digit drainage areas. The OWB data replaces the following data classes: * [Provincial Watersheds, Historical](https://data.ontario.ca/dataset/provincial-watersheds-historical)

100 year peak flow isolines in cubic metres per second (m3/s) for 100 square kilometre watersheds and 100 year return period

This data includes the projected capacity, energy potential and cost of possible hydro sites throughout the Yukon. Other sites will be added as the data becomes available.Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection.For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

This dataset was developed to provide a complete record of salmon rivers within the province of Newfoundland and Labrador. It is organized by DFO detachment area and can be used for resource planning and management purposes. It is suitable for general mapping, visualization and query. It is derived from the National Hydro Network (NHN) data.The geodatabase contains feature datasets for each of the 8 DFO detachments in Newfoundland and Labrador (Bay Roberts, Clarenville, Goose Bay, Marystown, Rocky Harbour, Springdale, Stephenville, Twillingate). Each of the feature datasets contain 4 feature classes that describe aspects of the salmon rivers within each detachment area. The RiverBasins feature class contains polygons outlining the extent of each of the salmon river watersheds that fall within that DFO detachment area. Polygons were delineated using provincial DEMs, National Hydro Network (NHN) river features, the DFO detachment area boundary, and tools contained in the ArcHydro toolset for ArcPro GIS software. The SalmonNetwork feature class contains lines which show the flow (undirected) of the river network through each of the salmon river watersheds that fall within that DFO detachment area. The flow is depicted by lines that run through rivers and streams and through waterbodies. The lines were imported from the National Hydro Network (Primary Directed Flow feature class) and then organized by salmon river watershed, to create a dataset with one line feature for each watershed. The SalmonRivers feature class contains lines which show salmon rivers within each of the salmon river watersheds that fall within that DFO detachment area. The lines were imported from the National Hydro Network (SLWater feature class) and then organized by salmon river watershed, to create a dataset with one line feature for each watershed. Only "single-line" rivers are included. Larger, "two-sided" rivers are depicted as polygons in the "Salmon Waterbodies" dataset.This SalmonWaterbodies feature class contains polygons which show salmon waterbodies within each of the salmon river watersheds that fall within that DFO detachment area. The polygons were imported from the National Hydro Network (Waterbody feature class) and then organized by salmon river watershed, to create a dataset with one polygon feature for each watershed. Larger, "two-sided" rivers are also depicted as polygons in the "Salmon Waterbodies" dataset.The geodatabase contains attribute information on the name, zone and class of each salmon river as reflected in the following documents: (i) Anglers' Guide - Scheduled Salmon Rivers of Newfoundland and Labrador and (ii) Conservation and Protection - Scheduled Salmon Rivers & DFO Detachment Regions Newfoundland and Labrador. It also provides links to online information on current in-season status

All fundamental watershed polygons generated from watershed boundary lines, bank edges, delimiter edges, coastline edges, and administrative boundary edges

Boundaries (polygons) of areas designated as community watershed by government - that are all or part of the drainage area that is upslope of the lowest point from which water is diverted for human consumption by a licensed waterworks, if satisfied that, to protect the water that is diverted for human consumption, the area requires special management that is not otherwise provided for under this regulation or other enactment: to conserve the quality, quantity and timing of water flow; or to prevent cumulative hydrological effects that would have a material adverse effect on the water . Supercedes the '(DEPRECATED) BC Community Watersheds' dataset BC_COMMUNITY_WATERSHEDS

All named watershed polygons