In the hydrogeological unit, quantity of water that replenishes groundwater beneath the water table, expressed in mm/yr. Recharge is usually calculated using hydrology balance, integrating information from precipitation, hydrology data, drainage, soil properties, evapotranspiration, etc. The result is a raster dataset in which each cell has a given value for the recharge of the aquifer. It can be calculate using HELP software, developed by the US EPA. The methods used to create the dataset are described in the metadata associated with the dataset. The dataset represent a raster in which each cell has a mean value describing the global annual recharge of the hydrogeological unit.

Polygon features represent developed ground water aquifers in BC (that have been mapped). Most aquifer boundaries are delineated based on geology, hydrology and topographic information. Some aquifer boundaries stop at the border of BC mapsheet boundaries due to resource or data constraints at the time of mapping.

Zones of homogeneous low flow characteristics

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)

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.

Zones that represent areas of homogeneous hydrologic and geomorphological characteristics

The “Terrestrial Ecoprovinces of Canada” dataset provides representations of ecoprovinces. An ecoprovince is a subdivision of an ecozone and is characterized by major assemblages of structural or surface forms, faunal realms, and vegetation, hydrology, soil, and macro climate. For example, the Newfoundland ecoprovince (no. 6.4) is one of six ecoprovinces within the Boreal Shield Ecozone

The BC Hydrologic Zones represent regions of similar climate and terrain resulting in somewhat homogeneous hydrology characteristics. The zones were defined previously by Obedkoff and others. This dataset has been extended into the neighbouring province, territories, and states for regional flood frequency analysis studies. See Bulletin 2020-1-RFFA British Columbia Extreme Flood Project – Regional Flood Frequency Analysis – Technical development report and manual to complete a regional flood frequency analysis.

Ontario Integrated Hydrology (OIH) data is used to generate watersheds and support provincial-scale hydrology applications including: * watershed generation * hydrologic modelling * watercourse network analysis Four key datasets are represented in each data package: * stream network (Enhanced Watercourse) * hydrology-enforced digital elevation model [DEM ] (Enforced DEM) * flow direction grid (Enhanced Flow Direction - EFDIR) * raster representation of the stream network (StreamGrid) __Technical information__ For the first time, OIH data is complete for the entire province making it possible to create a watershed for any location in Ontario. This includes areas flowing in from neighbouring provinces and Minnesota with the following exceptions: * points on the international border that drain to Lake Superior, south of Pigeon River * points on the international border that drain the Great Lakes connecting channels and St. Lawrence River stateside * points along the Ottawa River that drain from Quebec __Special note: North West package__ The North West package contains hydrography data for the entire Rainy River Basin, an area which straddles the international border between Canada and the United States. The data stateside originates from the National Hydrography Dataset (NHD) as of February/March 2014. This data has been harmonized with the Ontario Hydro Network (OHN) to create the Enhanced Watercourse and Integrated Waterbody layers found within the North West package. For more information on when the data was initially extracted and incorporated, refer to these fields stored in the attribute table of each vector layer in the geodatabase: * Effective Date (EFF_DATE) * Geometry Update Date (GEO_UPD_DT) The data stateside is a static snapshot of NHD intended to support regional modeling. Please refer to the [United States Geological Survey (USGS)](https://www.usgs.gov/core-science-systems/ngp/national-hydrography) website for the most current version of NHD. Data is updated after the completion of major updates to source data (such as OHN and/or the Provincial DEM).

The Baseline hydrology statistics (stream flow regime) in the Southwestern Hudson Bay and Nelson River watershed systems were produced for the Water Survey of Canada's HYDAT database. These baseline statistics provide information on the water quantity at each Water Survey Canada gauge location . They also provide a summary at a primary watershed scale. This data helps address the previous data gaps in the Far North region. Applications include: * land use planning * integrated watershed management * climate change studies * hydropower studies