Spring Safety

Spring weather brings warmer temperatures and creates new opportunities for recreational activities. However, it can also bring an increased risk of flooding from melting snow and ice and unstable conditions in and around bodies of water.

Seasonal Flooding Risks

When the temperatures start to rise in early spring, frozen ground prevents melting snow or rainfall from seeping into the ground (known as runoff or overland flow). This water runs off the ground and flows into Lake Ontario and local rivers and streams, creating the potential for excess water to spill over riverbanks.

Together with seasonal storms, this can result in spring flooding from river systems.

River ice can also form along watercourses during long cold spells in the winter months. This ice cover on rivers can either gradually melt away with steadily increasing air temperatures in the spring, or break up into pieces if air temperatures or water levels change quickly.

An ice jam occurs when those ice pieces are carried downstream along a watercourse and become stuck, blocking the flow of rivers and streams.

follow TRCA spring safety advice and avoid recreational activities near ice jams and bodies of water
Avoid recreational activities near ice jams or ice-covered rivers (shown above), streams, and bodies of water.

Spring Safety Tips

  • Riverbanks can become unstable in the spring due to snowmelt and erosion.
  • Keep family and pets away from the surfaces and edges of all bodies of water to prevent falling through or into cold and fast flowing water.
  • Avoid recreational activities in or around water bodies, especially near ice-covered rivers and streams at this time of year.
  • Do not attempt to walk, skate or drive on ice-covered bodies of water.
  • Never drive through flooded roads or fast-moving water.
  • If you live next to a river or stream, move patio furniture or other objects away from the water’s edge to avoid losing them during potential spring high water.
  • Rescuing another person or a pet from icy or fast flowing water is dangerous. If you see someone has fallen in a body of water, call 911 for help immediately.


How Does TRCA Mitigate Spring Flood Risks?

1. Implementing flood plain management policies is the primary tool in reducing exposure to flood risk.

2. Operating a Flood Forecasting and Warning Program. TRCA issues flood messages to local municipalities, school boards, the media and members of the public who self-subscribe. The program operates 24 hours a day, seven days a week.


3. Monitoring conditions across TRCA’s jurisdiction and providing local agencies and the public with notice, information, and advice so that they can respond during severe rainfall events that could lead to flooding. Visit TRCAgauging.ca to view real-time water levels in your local river or stream.

4. Operating and maintaining a suite of flood control infrastructure, including dams and channels.

Palgrave Dam
TRCA manages 12 dams, including Palgrave Dam in Caledon (above), as well as nine flood control channels, and six dikes across the Greater Toronto Area.

How Do Conservation Authorities Monitor
River Ice and Snow Conditions for the Spring Thaw?

  • Throughout the winter and early spring months, TRCA monitors river ice conditions and takes snowpack measurements in different areas of the TRCA jurisdiction. Staff use this information to assess for the potential risk of flooding due to ice jams and significant snowmelt events.
  • Monitoring information is shared with local municipalities if the flood risk is high.
  • If flood risk is determined to be high based on monitored conditions, TRCA may issue a flood message.
  • The program also includes advanced tools for monitoring in the field, such as Geographic Information System (GIS) mapping services and drone footage.

Learn more by visiting TRCA’s Flood Forecasting and Warning Centre.

melting snow in spring

Who is Responsible for Dealing with Riverine Flooding?

The responsibility for dealing with flood contingency planning in Ontario is shared by municipalities, Conservation Authorities (CAs), and the Ministry of Natural Resources and Forestry on behalf of the Province.

TRCA is responsible for operating a Flood Forecasting and Warning Program, which includes issuing flood messages and providing advice and technical information to local and regional municipalities. LEARN MORE.

Past Spring Flooding Events in the GTA

TRCA team members view impact of spring flooding event on Toronto Islands

In 2017 and 2019, Lake Ontario experienced seasonal higher-than-average water levels. The peak water level is heavily influenced by rainfall over the course of the spring months as well as the unregulated inflow from Lake Erie and the regulated outflow of Lake Ontario into the St. Lawrence River.

Get More Information

Additional Resources