Atlas of Canada National Scale Frameworks data are standardized national coverages of commonly used geospatial datasets at the 1:1 000 000 scale. A variety of framework layers (e.g. hydrology, roads, ferry routes, railways, administrative boundaries, census subdivisions, population ecumene, drainage areas, protected areas and Canadian place names) have been integrated so that their relative positions are correct. Hydrology (which includes coastline) is the base layer to which all others are fitted.

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 (FDA) dataset (sub-sub-basin level), of the WSC and the National Atlas of Canada (NA) (AC) 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.

• Drainage
• Hydrography
• Lakes
• Surface water
• discharge
• flow