This product provides the boundaries for the 25 drainage regions in Canada and the five ocean drainage areas. These drainage regions cover all of the area within the coastal boundaries of Canada.These files were produced by Statistics Canada, Environment, Energy and Transportation Statistics Division, 2009, special tabulation of data from Pearse, P.H., F. Bertrand and J.W. MacLaren, 1985, Currents of Change: Final Report of the Inquiry on Federal Water Policy, Environment Canada, Ottawa.

This theme includes the drainage areas of various watercourse monitoring stations (physicochemical and bacteriological, benthic organisms, diatoms, pesticides, etc.) carried out by the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP) as well as lake catchments (MELCCFP) as well as lake catchments including the majority of lakes in the Voluntary Lake Monitoring Network (RSVL).The drainage area and the watershed represent the territory whose water flows to the sampling station or to the outlet of the lake. Boundaries are generated using a geographic information system (GIS) from topographic maps, numerical elevation models and flow models, and watershed boundaries produced by the Main Directorate of Water Expertise (DPEH).The drainage area and watershed are used to calculate the area drained upstream of the sampling station or lake, to characterize the drained territory (for example, to determine land use), and to meet specific mapping needs. The linked tables also provide compilations of land use according to three classifications to contextualize the various monitoring carried out at the stations. Note that the use of land outside Quebec, drainage areas and transboundary watersheds is not calculated and that the percentages in each category correspond to the Quebec area only.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

The "Areas of Non-Contributing Drainage within Total Gross Drainage Areas of the AAFC Watersheds Project - 2013" dataset is a geospatial data layer containing polygon features representing the areas within the “total gross drainage areas” of each gauging station of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project that DO NOT contribute to average runoff. A “total gross drainage area” is the maximum area that could contribute runoff for a single gauging station – the “areas of non-contributing drainage” are those parts of that “total gross drainage area” that DO NOT contribute to average runoff. For each “total gross drainage area” there can be none to several unconnected “areas of non-contributing drainage”.These polygons may overlap with those from other gauging stations’ “total gross drainage area”, as upstream land surfaces form part of multiple downstream gauging stations’ “total gross drainage areas”.

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)

The "Total Effective Drainage Areas of the AAFC Watersheds Project – 2013” dataset is a geospatial data layer containing polygon features representing the areas within the “total gross drainage areas” of each hydrometric gauging station of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project that would contribute to average runoff. A ‘total gross drainage area’ is the maximum area that could contribute runoff for a single gauging station – the ‘total effective drainage areas’ are those parts of that ‘total gross drainage area’ that would contribute surface runoff to an average runoff. For each “total gross drainage area” there can be only one “total effective drainage areas”.These polygons may overlap with those from other gauging stations’ “total gross drainage area”, as upstream land surfaces form part of multiple downstream gauging stations’ “total gross drainage areas”.

The “Gross and Effective Drainage Area Boundaries of the AAFC Watersheds Project - 2013” dataset is a geospatial data layer containing line features representing boundaries associated with the ‘incremental gross drainage areas’ of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project. The project is subdivided by hydrometric gauging station. The maximum area that could contribute runoff to each station, less that of its upstream neighbour(s) is called its ‘incremental gross drainage area’. Two types of boundary are provided: ‘gross’ and ‘effective’. ‘Gross’ boundaries separate adjacent incremental gross drainage areas. ‘Effective’ boundaries delimit, within each incremental gross drainage area, the separation between areas that supply runoff, based on average runoff, from those that don’t.

The “Incremental Gross Drainage Areas of the AAFC Watersheds Project - 2013” dataset is a geospatial data layer containing polygon features representing the incremental gross drainage areas of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project. The Project area is subdivided by hydrometric gauging station. The maximum area that could contribute runoff to each station, less that of its upstream neighbour(s) is called an ‘incremental gross drainage area’.

The “Non-contributing Portions of the Incremental Gross Drainage Areas of the AAFC Watersheds Project – 2013” dataset is a geospatial data layer containing polygon features representing the areas within each incremental gross drainage area of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project that DO NOT contribute to average runoff. The Project is subdivided by hydrometric gauging station. The maximum area that could contribute runoff to each gauging station, less that of its upstream neighbour(s) is called an “incremental gross drainage area”. The “incremental gross drainage” areas can be subdivided into portions that either supply surface runoff to an average runoff, or do not. Those portions that are NOT part of the effective drainage area are called ‘non-contributing'.

The “Incremental Effective Drainage Areas of the AAFC Watersheds Project– 2013” dataset is a geospatial data layer containing polygon features representing the portions of each incremental gross drainage area of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project that could be expected to contribute to surface runoff under average runoff conditions. An ‘incremental gross drainage area’ is a hydrometric gauging station's drainage basin, less that of the next upstream gauging station(s)’. ‘Effective drainage’ occurs in areas that are expected to supply surface runoff in an average runoff.

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, 1945-2011Further information on all these maps can be found on the Atlas of Canada web site atlas.gc.ca.