Canada1Water Digital Terrain Model with Bathymetry dataset

National integrated water modelling of Canada required a (DEM) Digital Elevation Model for all continental Canada at a single resolution, with bathymetry, and inclusion of transboundary watersheds with the United States. Such a model was not available and hence the Canada1Water project developed a Digital Terrain Model (DTM) that integrates high resolution elevation data from derivative Arctic (2 m) and NASADEM (30 M) DEM with open-source bathymetry data for lakes ≥10 km 2 . The DTM was brought to a standard datum and projection, resampled to a standard horizontal scale, and corrected for void issues and canopy biases. The result is the 1-arcsecond grid (∼20 m) Canada1Water Digital Terrain Model (C1W-DTM). The new DTM provides a standard elevation datum for all subsurface modelling as well as a constraint for the surface hydraulic flow system. A seamless DTM with lake Bathymetry was essential to support the control volume HydroGeoSphere modelling environment being used. This dataset supports a wide range of applications requiring a DTM with lake bathymetry thus enabling more accurate and informed decision-making.