The Ontario Hydro Network (OHN) is a provincial medium scale originating from data with regional scales of 1: 10,000 in Southern Ontario, 1: 20,000 in Northern Ontario and 1: 50,000 in the Far North. The shoreline is taken from the OHN - Waterbody data class. This data is used for cartographic purposes and web mapping services. This product requires the use of geographic information system (GIS) software. [Ontario Hydro Network (OHN) User Guide (Word)](https://www.sdc.gov.on.ca/sites/MNRF-PublicDocs/EN/CMID/OHN%20-%20UserGuide.docx)

Data has been collected primarily using a depth measurement device, such as an echo-sounder, in combination with a Global Positioning System (GPS) for horizontal positioning. Other survey methods, such as bathymetric LiDAR may also have been used. The survey method used in each body of water is shown in the [Bathymetry Index](https://geohub.lio.gov.on.ca/datasets/mnrf::bathymetry-index ).

This spatial dataset represents the boundaries of the areas of responsibility for aggregate inspectors working on behalf of the Ministry of Natural Resources and Forestry. In southern Ontario, inspectors may use various criteria to determine their area of responsibility, including: * geographic township boundaries * the number of licences and permits in a given area * geographic size In northern Ontario, areas of responsibility generally follow MNRF district boundaries. Use our interactive [Pits and Quarries map](https://www.ontario.ca/page/find-pits-and-quarries) to learn more about active aggregate sites and designated areas.

A feature is a representation of a real world object, such as a lake, stream, dam or rapid. There are three hydrographic feature classes:  points, lines and polys. All may impede or be hazardous to waterflow and/or navigation on a watercourse or waterbody. This data shows natural and manmade point features. Examples include: * waterfalls * rapids * rocks * Sea Lamprey barriers * shipwrecks This product requires the use of geographic information system (GIS) software. [Technical Bulletin: Data migrated to new Ontario Hydro Network (OHN) - Hydrographic Feature Data Classes (PDF)](https://geohub.lio.gov.on.ca/datasets/mnrf::ontario-hydro-network-ohn-hydrographic-point/)

A building is a structure that has a roof and walls and stands more or less permanently in one place. Symbols are used when buildings and structures are permanent landmarks. Symbolized buildings have no side larger than 50 metres for 1:20,000 data or no side larger than 30 metres for 1:10,000 data. Small structures (including buildings less than 50 square metres) are not shown unless they constitute a point of orientation. This product requires the use of geographic information system (GIS) software. [Land Information Ontario: Data Class Fact Sheet - Building to Scale (PDF)](https://www.sdc.gov.on.ca/sites/MNRF-PublicDocs/EN/CMID/Building%20to%20Scale%20-%20Data%20Description.pdf)

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.

This dataset represents the locations of licenced and permitted pits and quarries regulated by the Ministry of Natural Resources and Forestry under the Aggregate Resources Act, R.S.O. 1990. Aggregate site data has been divided into active and inactive sites. Active sites may be further subdivided into partial surrenders. In partial surrenders, defined areas of a site are inactive while the rest of the site remains active. The data includes: * site location and size * licensee name * approval type (licence or permit) * operation type (pit or quarry) * maximum annual tonnage limit * the MNRF district responsible for the site Use our interactive [pits and quarries map](https://www.ontario.ca/page/find-pits-and-quarries) to find active sites. This data does not include [aggregate sites regulated by the Ministry of Transportation](https://data.ontario.ca/dataset/ministry-of-transportation-aggregate-sites).

The Ontario Road Network (ORN) Composite product is a segmented derivative of the ORN Road Net Element (ORNELEM) data class. You can use it for mapping and general spatial analysis. Road segment information includes: * addressing * full street name * alternate street name * speed limit * number of lanes * pavement status * road class * jurisdiction * route number * direction of traffic flow * shield type information The ORN is a provincewide geographic database of over 250,000 km of: * municipal roads * provincial highways * resource and recreational roads The ORN is the authoritative source of roads data for the Government of Ontario. This product is derived from the [ORN Road Net Element](https://geohub.lio.gov.on.ca/datasets/mnrf::ontario-road-network-orn-road-net-element/about) data class. It combines three types of geometry: * road elements * ferry connections * virtual roads This product also includes additional road feature layers including: * blocked passages * underpasses * toll points * structures

This Ontario Hydro Network (OHN) small scale dataset is intended for cartographic and web mapping display purposes, not for analytical work. Small scale waterbody, watercourse and shoreline data is available at the following seven scales: * 1:100,000 * 1:200,000 * 1:500,000 * 1:1,000,000 * 1:2,000,000 * 1:5,000,000 * 1:10,000,000 Search the [Land Information Ontario (LIO) Warehouse OHN Products Composite File Geodatabase](https://geohub.lio.gov.on.ca/datasets/land-information-ontario-lio-warehouse-ontario-hydro-network-ohn-products-composite-file-geodatabase) to download a file geodatabase of all the OHN’s publicly available (Open) derivative cartographic products taken from the LIO Warehouse on a bi-weekly basis.

The National Hydro Network (NHN) focuses on providing a quality geometric description and a set of basic attributes describing Canada's inland surface waters. It provides geospatial digital data compliant with the NHN Standard such as lakes, reservoirs, watercourses (rivers and streams), canals, islands, drainage linear network, toponyms or geographical names, constructions and obstacles related to surface waters, etc. The best available federal and provincial data are used for its production, which is done jointly by the federal and interested provincial and territorial partners. The NHN is created from existing data at the 1:50 000 scale or better. The NHN data have a great potential for analysis, cartographic representation and display and will serve as base data in many applications. The NHN Work Unit Limits were created based on Water Survey of Canada Sub-Sub-Drainage Area.