Bathymetry is the measurement of water depth in lakes. From the 1940s to the 1990s, the Ministry of Natural Resources and Forestry produced bathymetry maps for over 11,000 lakes across Ontario. The data can be used by the general public and GIS specialists for: * climate change modelling * fish monitoring and other ecological applications * hydrologic cycle modelling * recreational fishing maps * watershed-based water budgeting The maps were created using simple methods to determine lake depths. They were meant for resource management purposes only. Little effort was made to identify shoals and other hazards when creating these bathymetric maps. Since this data was collected, many constructed and naturally occurring events could mean that the depth information is now inaccurate, so these maps should not be used for navigational purposes. In many cases, these maps still represent the only authoritative source of bathymetry data for lakes in Ontario. __Technical information__ These maps are being converted to digital GIS line data which can be found in the [Bathymetry Line](https://geohub.lio.gov.on.ca/datasets/mnrf::bathymetry-line) data class. The [Bathymetry Index](https://geohub.lio.gov.on.ca/datasets/mnrf::bathymetry-index) data class identifies if GIS vector lines have been created and the location of mapped lakes. The historic paper maps have been scanned into digital files. We will add new digital files to this dataset if they become available. The digital files have been grouped and packaged by regions into 13 compressed (zipped) files for download. Note: package 99 contains scanned maps where the location shown on the map could not be determined.

The dataset has been used for the Great Lakes Conservation Blueprint Project for Aquatic Biodiversity. It can be used for: * research and aquatic species inventories * environmental impact and monitoring * watershed based resource planning and management * fisheries and other aquatic analysis Official GEO title: Aquatic Ecosystems Classification: Great Lakes Basin - Coast, Streams, Lakes and Wetlands

Foreshore Plant Habitat Zones for Okanagan region lakes. The purpose of this data is to support the Large Lakes Protocol, an interagency document that addresses the processes that need to be followed during foreshore development. The required application process varies depending on habitat value zone

All available bathymetry and related information for Twin Lakes were collected and hard copy maps digitized where necessary. The data were validated against more recent data (Shuttle Radar Topography Mission 'SRTM' imagery and Indian Remote Sensing 'IRS' imagery) and corrected where necessary. The published data set contains the lake bathymetry formatted as an Arc ascii grid. Bathymetric contours and the boundary polygon are available as shapefiles.

The Nova Scotia Lake Survey program is a partnership initiative between the Department of Environment and Climate Change and the Department of Fisheries and Aquaculture to inventory lakes throughout the province determining baseline water quality, in support of both sport fisheries and water resource management areas. The following weblink connects to a Department of Environment and Climate Change web map that includes the locations of the monitored lakes within the province and an alternative method for downloading the same lake chemistry dataset: http://nse.maps.arcgis.com/apps/webappviewer/index.html?id=7ded7a30bef44f848e8a4fc8672c89bd"

Kokanee habitat zones for Okanagan region lakes. The purpose of this data is to support the Large Lakes Protocol, an interagency document that addresses the processes that need to be followed during foreshore development. The required application process varies depending on habitat value zone. The data was sourced from Kokanee Shore spawner inventory data

Spot Height Points for the Pasqua, Crooked, Echo, and Round Lakes area within the Qu'Appelle Valley River system in Saskatchewan

Shorelines for the Pasqua, Crooked, Echo, and Round Lakes within the Qu'Appelle Valley River system in Saskatchewan

Contour Lines for the Pasqua, Crooked, Echo, and Round Lakes within the Qu’Appelle Valley river system in Saskatchewan

Flight lines for the Pasqua, Crooked, Echo, and Round Lakes area within the Qu'Appelle Valley River system in Saskatchewan