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

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)

Note: This data has been replaced by the [Ontario Watershed Boundaries (OWB)](https://geohub.lio.gov.on.ca/datasets/mnrf::ontario-watershed-boundaries-owb).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.

Watershed boundary delineated for Canada-BC hydrometric stations. Currently, watersheds were delineated using 1:50,000 scale boundaries in 1996, and many watersheds encompass entire drainages, instead of just the upstream watersheds. Note - Not yet available, but we are in the process of generating BC hydrometric station upstream watersheds using updated base data, using the following method: Within BC, watershed boundaries are based on the 1:20,000-scale Freshwater Atlas fundamental watersheds, and trimmed using the BC TRIM DEM used to approximate the height-of-land at the station locations. Outside of BC, but within Canada, watershed boundaries were approximated using Canada CDED DEM data for delineation (no "stream burning" was used) and some manual editing of boundaries was done to approximately match hydrology data after the fact. Within U.S.A., the USGS Watershed Boundary Dataset was used (at the best scale available for each drainage) to delineate the watershed boundary, with the watershed trimmed using the USGS National Elevation Dataset to approximate the height-of-land when necessary.

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.

The Drainage Areas dataset is largely based on the Water Survey of Canada (WSC) drainage area boundaries at the sub-sub-basin level. The data model supports the derivation, from the Fundamental Drainage Areas dataset (sub-sub-basin level), of the WSC and Atlas of Canada drainage area hierarchies and the data is available in all three schemes. Drainage area definitions for both WSC and Atlas of Canada boundaries were reviewed resulting in some modifications. Larger scale reference data sources were used for further manual boundary adjustments. This dataset has been integrated with other National Scale Frameworks hydrology datasets and is considered a component of the Hydrology Theme (see Supplemental Information for more details about the Atlas of Canada National Frameworks data at the 1:1,000,000 scale). The Atlas Frameworks are a set of integrated base map layers which form part of a larger National-Scale Frameworks data collection. These data have been compiled at a scale of 1:1 000 000 with the primary goal being to indicate correct relative positioning with other framework layers rather than absolute positional accuracy. 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)

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).

This dataset is the digital hydrologic unit boundary layer for the 8-digit subwatershed boundaries for the conterminous United States. This dataset is intended to be used with the following two tabular dBase files: https://water.usgs.gov/lookup/getspatial?ds573_tillage_lu92e and https://water.usgs.gov/lookup/getspatial?ds573_tillage_lu01. The two tabular datasets contain the Tillage Practices in the Conterminous United States, 1989-2004---Datasets Aggregated by Watershed. This dataset and the two tabular datasets can be linked using the common attribute HUC8_N. Information about how the tabular data and geospatial data can be related are given in the data series report: https://pubs.usgs.gov/ds/ds573/ .The original dataset is the 12-digit Subwatershed boundaries (WBD_archive_17nov2009_9.2_file). The 12-digit boundaries were dissolved to 8-digit boundaries to be used with the two tabular .dbase data files containing the tillage practice data for the United States. ORIGINAL METADATA: This data set is a complete digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the entire United States. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "Federal Guidelines, Requirements, and Procedures for the National Watershed Boundary Dataset; Chapter 3 of Section A, Federal Standards, Book 11, Collection and Delineation of Spatial Data; Techniques and Methods 11-A3" (04/01/2009). http://www.ncgc.nrcs.usda.gov/products/datasets/watershed/index.html . Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, 6th level subwatersheds, name, size, downstream hydrologic unit, type of watershed, non-contributing areas and flow modification.