Safety Around Dams/Flood Control Structures

Stay off Dams and Flood Control Structures

These structures were created for a specific purpose and only qualified personnel are allowed on the structures.

(Source: Ministry of Natural Resources, Published: July 18, 2014)

Stay off dam structures unless an area is clearly marked for public travel. You should also be alert to changes in water levels.

Summer

  • always stay outside booms and away from all dam structures
  • never swim above a dam or dive from a dam structure (currents can pull you through the dam or against flow structures with such force that you could not escape)
  • never fish, boat, or swim below a dam (water levels and flows can change very quickly and you may not be able to react in time to avoid the danger)
  • personal watercraft and boats should always stay clear of dams
  • never moor, tie or anchor your boat below a dam
  • never sunbathe, picnic or camp in an area which may become flooded due to dam operations

Autumn

  • be aware of possible changes in water flows or levels from dam operations
  • always obey posted signs, and do not enter fenced areas to hike or gain access to other areas

Winter

  • beware of thin ice that may develop due to dam operations
  • never venture out on the ice alone
  • always wear a floatation suit and carry a throw rope
  • dam operators often lower water levels during winter and spring
  • always be aware of the potential for slush under the snow

Spring

  • stay clear of dams when fishing (water flows and levels can change quickly)
  • always stay clear of dams when canoeing or kayaking

Dam hazards

Regardless of their size, type or intended use, all dams present certain hazards to those who work or play near them. Pay attention to signs, booms, buoys and fencing.

Low head weirs

  • while low head weirs may appear insignificant, they pose considerable dangers to those boating or playing around them
  • water that continuously re-circulates at the base of low head weirs creates underwater hydraulics which can easily trap someone underwater at the base of the dam
  • low head weirs may have no visible structure above the water line (boaters approaching a weir from the upstream side may not be aware of the dangers present)
  • always watch for and obey signs, booms, buoys and portage markers

Water conditions

  • upstream dam leakage between and around stop logs can pull swimmers in and drag them below the water level with such force they can’t escape
  • air trapped in water reduces your buoyancy (if you’re caught in foaming water, you will find it harder to stay afloat even with the aid of personal floatation gear)
  • changing water levels and flows below a dam can occur rapidly and without warning
  • never place yourself in a situation where you can’t leave the area you are boating in
  • never camp, picnic or sunbathe in an area below a dam which may become flooded

Retaining walls

Concrete retaining walls above and below dams can block exit routes. These are often present near marine locks.

Want to learn more? Resources on dam safety:

Association of State Dam Safety Officials (ASDSO) – http://livingneardams.org/

Ontario Power Generation – https://www.opg.com/about/safety/water-safety/Pages/water-safety.aspx

Visit TRCAgauging.ca for gauging and water level information.