Emergency Management Facts
Learn more about the hazards for which MNR has been assigned lead responsibility and about the things you can do to protect yourself and your family.
You must have a PDF reader to view the fact sheets in PDF format. A free PDF reader is available from the Adobe website.
MNR has responsibility to lead the management of the following seven hazards:
A forest fire is an unplanned and uncontrolled fire burning in vegetation fuels such as forest, grass and brush. Forest fires are part of nature and occur either from lightning or human activity.
When referring to the hazard of forest fires we are specifically speaking about those unwanted fires having a negative impact on people, property, economic stability and the environment.
The number of fires in Ontario averages 1500 annually. Yearly forest fires may cause the evacuations of communities and cottage subdivisions due to the proximity of the active fire or as a result of smoke produced by the fire and the related health issues.
The control of forest fires requires an organized and coordinated response. By keeping the majority of forest fires to a relatively small size, MNR reduces the threat to most property and infrastructure across the forested landscape.
A flood is an overflowing or influx of water beyond its normal confines. Floods can occur at any time of the year and are caused by storms, heavy rains, ice jams, wind related storm surges across large lakes, or the failure of dams. Vulnerable areas are called flood plains or flood hazard lands.
Ontario has a history of severe flood events, including the devastating Hurricane Hazel flood of 1954 that caused 81 deaths and an estimated $133 million in damages. In response to flooding, Ontario created Conservation Authorities which mitigate the impact of flooding.
The Ontario Ministry of Natural Resources Surface Water Monitoring Centres maintains a watch of stream flow levels and weather forecasts to predict when and where flooding is likely to occur.
Drought is defined as weather and low water conditions characterized by below normal precipitation for an extended period of time.
Droughts cause many severe impacts on the environment and communities including: water shortages for human consumption, industrial, business and agriculture needs, decline of water quality, increase in wildfires, increases in insect infestations and plant disease and wind erosion.
Historically, periods of dry weather and low water levels or drought are relatively uncommon in Ontario (about every 10-15 years).
Erosion is the loss of land, due to human or natural processes. Erosion is a natural process near all rivers, streams and lakes in Ontario. The rate of erosion is sometimes accelerated as a result of flooding and increased runoff associated with changing land uses in the watershed.
On the Great Lakes, lake level fluctuations, storm events and related natural processes continuously reshape the coast. In 1985-86, property owners on the Great Lakes coasts experienced record high lake levels in the century. The high lake levels combined with a number of severe storms caused substantial damages to public and private properties.
Unstable soils (leda clays and organic soils) and unstable bedrock (karst formations) are naturally occurring and have shaped and re-shaped the landscape for thousands of years.
Leda clays were deposited as sediment during the last glacial period. Undisturbed, the clays can appear solid and stable, but when disturbed by excessive vibration, shock or when they become saturated with water, the clays can turn to liquid, sometimes in minutes. The triggers that bring on the change can vary: earthquakes, thunder, heavy traffic, blasting, heavy rainfall or water from spring runoff, loss of vegetation, or placement of heavy buildings or fill on the site.
Organic and peat soils are formed by the decomposition of vegetative materials. This rotting process can release various acids to the ground water system and create methane gas, which is highly explosive. Peat soils are usually formed in association with water such as within wetlands.
Unstable bedrock sites in Ontario are usually karst formations. Karst formations are areas where water flowing over and through limestone and dolomite bedrock creates sinkholes, trenches and underground caverns.
A dam is a barrier across a river, lake, pond or stream, intended to hold back water in order to raise its level or divert the flow of water. A dam failure results in the rapid uncontrolled release of water which may cause rapid flooding.
Dam failures can be the result of natural events such as prolonged rain or earthquakes or they can be the result of human activities.
There are about 2400 dams in Ontario, approximately 1,000 of which are privately owned. The federal or provincial government, Ontario Power Generation and Conservation Authorities own the rest.
Ontario has not directly experienced a large disaster related to dam failure. Today’s dams are typically designed and operated to safely pass very large flood flows without failure, while ensuring the ongoing structural and functional integrity of the dam.
An emergency in this area is defined as an event that poses threat to public safety from the uncontrolled release of oil and/or natural gas from wells or storage systems. Crude oil can have devastating impacts on the environment if it escapes wells or storage facilities. There have been several incidents of oil spills in Ontario. In 1997, there was a “blowout” of a production well which spilled oil and brine over a large area resulting in soil and groundwater contamination. About 20 homes were evacuated.
