Ontario Hydro Network (OHN) - Hydrographic

Revision Note: Please note that this dataset has been revised and is available from the Land Information Ontario (LIO) Warehouse

Natural or manmade features that occur on waterbodies or watercourses which may pose hazards or impediments to waterflow or navigation. Some features are represented as all three types, point, line and polygon for use at different scales while other features are represented only as points or lines or polygons.

· Falls - A perpendicular or steep drop in a body of water over which water flows.

· Rapids - A fast-flowing, often turbulent, section of a body of water, generally containing exposed rocks or boulders.

· Rocks - A rock or earthen formation always visible above the water surface.

· Dam - A feature representing an obstacle that disturbs or impedes the flow of surface water, excluding beaver dams, water-crossings and culverts.

· Hydro Wall - A manmade structure built in a waterbody and possibly extending onshore, or built along a waterbody forming the shoreline, that does not allow water to pass under it, but allows water to pass around it. Hydro walls may extend along and/or may be contained within a waterbody, and may include wharfs, docks, piers, jetties, headwalls, groynes, locks, berms or embankments.

· Lock-Gate - A gate on a navigable canal used to raise or lower the water level so that boats may pass from one level to another.

· Sea Lamprey Barrier - A feature on a watercourse or waterbody that forms a barrier (either electrical or physical) to the migration of Sea Lamprey.

· Wreck - The remains of a grounded ship that is partially above the water surface.

Supplementary look-up data tables are used and are referenced in the additional documentation - SNIF report.