Flooding

Introduction

Some waterways in Lambton County are capable of “nuisance” flooding caused by heavy rainfall, melting snow or ice dams.  Such flooding commonly results in local road closures during the spring, but rarely does it cause home or property damage.  Even so, there are some residents who live in areas that are susceptible to serious flooding such as the Port Franks area in Lambton Shores.  Port Franks has experienced significant flooding caused by ice jams in the Ausable River, which flows into Lake Huron.  Any waterway can become dangerous after a heavy rainfall or spring-melt, so keep watch over young children and be cautious around deep or fast flowing water.

Fortunately, the threat of widespread catastrophic flooding in Lambton County is low.  This is due in part, because of province-wide restrictions adopted after Hurricane Hazel in 1954, which prohibit or restrict construction in flood prone areas.  Intense rains that accompanied the hurricane caused extensive flood damage and loss of life in Ontario (81 people were killed in the Toronto area).  Restrictions on construction within waterways are now enforced through municipal Zoning By-laws and Conservation Authority Regulations, and have reduced the risks to property and human life associated with flooding.

You can obtain more information about your watershed from the Ausable-Bayfield Conversation Authority (which covers portions of Lambton Shores and Warwick) or the St. Clair Region Conservation Authority (which covers the remainder of the County).

You can also visit the Ministry of Natural Resources website to read current flood messages for the Province.

Watersheds of Lambton County and surrounding area.
Watersheds of Lambton County and surrounding area.

Types of Flooding

Flooding can result from snow-melt, ice dams and heavy rainfall.  Flooding is especially common in the spring following a snow melt or heavy rainfall when the ground is either frozen or saturated.  Rivers, streams and ditches can flow very fast and high, and even over-flow their banks.

Anywhere in the Province is susceptible to extreme rainfall events when a large amount of rain falls in a short period of time.  Areas not usually prone to flooding have been severely impacted by such events, such as Peterborough in July 2004 (see photo below) and Toronto in July 2013.

Peterborough Flooding
Downtown Peterborough flooding due to nearly 275mm
(7 inches) of rain received on July 15, 2004.

When you notice that it has been raining very hard and/or steadily for a long period of time, be alert to the possibility of flooding, even if you do not live near a watercourse.  Listen to a weather radio or visit the Environment Canada alerts website for information and issued weather alerts.

Know the Difference Between A Heavy Rainfall Warning, Flood Watch and Flood Warning.

Environment Canada is the official source for weather information, forecasts and alerts in Canada.  When Environment Canada determines that damaging, heavy rain is likely or is occurring, a Heavy Rainfall Warning will be issued.

  • HEAVY RAINFALL WARNING is issued when heavy or prolonged rainfall is sufficient to cause local/widespread flooding.  Expect 50 mm of rain over 12 hours or less, or 80 mm of rain in less than 24 hours.

The Ontario Ministry of Natural Resources and local Conservation Authorities are responsible for forecasting when and where flooding is likely to occur, and for issuing three types of flood messages:

  • Watershed Conditions Statement – Flood Outlook/Water Safety – is issued when general watershed conditions are being assessed for high runoff potential that could lead to flooding, and to remind the public of general river safety issues.
  • Flood Watch notifies the public that flooding is possible within specific watercourses and municipalities.
  • Flood Warning this is the most serious message.  It means that flooding is imminent or occurring within specific watercourses and municipalities.  Municipalities and residents should take action to deal with flood conditions, which could include road closures and evacuations.

Visit the website of the Office of the Fire Marshal to read information about flood safety, and view this Flood Pamphlet to learn how to prepare for flooding.

Before a Flood

When a Flood Watch has been issued for your area, you should:

  • Retrieve your 72 Hour Emergency Supplies Kit.  (If you do not have an Emergency Supplies Kit you need to prepare one, in advance of any type of emergency situation.)
  • Listen to a weather radio, or local radio station for updated emergency information.
  • Follow the instructions and advice of local authorities.
  • Make sure you have bottled water in storage, as flooding can contaminate water sources.
  • Bring in outdoor furniture and secure any items that could be swept away or damaged by floodwaters.
  • Move your furniture and valuables to higher floors in your home, as they are less likely to be damaged.
  • Turn off gas and electricity if you are asked to by authorities.  Learn where the shut-offs are located.

Floods can be unpredictable – be alert to the signs of flooding and be prepared to evacuate with your Emergency Supplies Kit immediately.

When a Flood Warning has been issued for your area, you should:

  • Retrieve your Emergency Supplies Kit.
  • Listen to a weather radio, or local radio station for updated emergency information.
  • Follow the instructions and advice of local authorities.
  • If you live in a flood-prone area or believe that you are at risk, evacuate immediately and move to higher ground.  Do not worry about personal belongings as they can be replaced – you cannot.
  • If you are advised to evacuate, do so immediately following the recommended evacuation routes.
  • Stay away from valleys and low-lying areas because they can become filled with water quickly.
  • When you are driving, and water is flowing across the road, so that you cannot see pavement, “TURN AROUND, DON’T DROWN!”  (watch video)

There are many instances of roads and culverts being washed away, but not visible below the surface of the water.  People have driven into these holes and drown.  If you are walking and come across a flowing stream where the water is above your ankles, stop, turn around, and go another way.  You can be swept away in as little as 15 centimetres (6 inches) of water.

Finch Ave Flooding
Finch Avenue culvert washed out following heavy rains in Toronto, August 2005.

After a Flood

Flood dangers do not end when the water begins to recede.  Take the following precautions after a flood:

  • Check on elderly neighbours and those with medical conditions that may need assistance.
  • Avoid entering any building before local officials have said it is safe to do so.  Buildings may have hidden damage that makes them unsafe (i.e., gas leaks, waterline or electrical damage).
  • When local authorities allow you to enter your home, be extremely careful of dangers such as electrical shock.
  • Report any broken utility lines to the appropriate authorities.  If you smell gas or hear a hissing sound, leave the building immediately and call the emergency number for your gas company.  You should have this information on-hand.
  • If electrical power is on in a flooded area, consult with your local electricity utility for assistance.
  • Do not use flooded appliances, electrical outlets, switch boxes, or fuse breaker panels until they have been checked by your local authority.
  • Make sure the building is structurally safe.  Look carefully for buckled walls or floors and watch out for broken glass and debris.
  • The water in your home could be heavily contaminated with sewage and other pollutants after a flood.  This is a health hazard.  Listen for instructions from your local public health unit as to what to do.
  • Household items that have sustained flood damage will have to be bagged, tagged, and discarded according to local regulations.  Special garbage pick-up might be arranged by your municipality.
  • Food items that have come into contact with floodwaters should be disposed of, with the exception of sealed canned goods.  The outside of sealed canned goods must be thoroughly washed and disinfected.
  • Special measures such as testing and decontamination may be needed to ensure the safety of private drinking water wells that have been flooded.
  • Contact your insurance provider if necessary.

For more information about flooding and protecting your home, visit The Canadian Mortgage and Housing Corporation website.

Culvert wash-out flooding in Dawn-Euphemia
Heavy rains cause a culvert wash-out in Dawn-Euphemia. Cracks from slumping indicate that the entire road width is unstable and unsafe to use.