Flood season is arriving to regions across Canada, posing a significant risk to infrastructure and potential loss of life.
Changing temperatures, melting snow and higher-than-normal precipitation all contribute to the threat of spring floods, according to B.C.’s Parliamentary Secretary for Emergency Preparedness Jennifer Rice. Provinces are pouring more money into disaster preparedness to battle these factors, but for now, cities cannot eliminate the possibility that flood waters will hit.
Since 2000, Canada has seen more than 80 big flood events. Last spring, record high-water flows washed through B.C’s Thompson Okanagan, forcing about 2,500 residents from their homes and communities, while torrential rainfall drowned the streets of Vancouver. Montreal had to declare a state of emergency and record-breaking springtime water levels in Lake Ontario caused the worst flooding the Toronto Islands, a popular tourist destination, have seen in decades. Calgary has remained on guard ever since the 2013 flood, which remains the costliest natural disaster in Canadian history.
Flooding causes millions of dollars in property damage, but it also welcomes increased pest activity and pest-related health risks. Structural damage creates pest-conducive factors, entry points and habourage. Flooding can also interfere with pest prevention methods owners and managers currently have in place. Traps, bait stations and treatments can be damaged or washed away, and when flood waters recede, accumulated debris attracts flies, scavenging beetles and cockroaches that will feed on the abundance of garbage and sewage overflow.
Mould is another unwanted consequence, attracting mould-feeding insects, such as plaster and fungus beetles. Wet or rotting wood left behind after flooding leaves a property at a higher risk for a carpenter ant infestation, and standing pockets of water provide breeding grounds for mosquitoes, midges and gnats.
Even if a property remains dry, it’s still at risk for pest activity as insects, rodents and wildlife seek relief from flood waters. This means that rats and cockroaches found in sewage and drainage systems will seek higher ground untouched by flooding. Crawling insects such as ants, ground beetles and wood roaches will escape the floods by migrating in large numbers into dry buildings.
Urban flooding is a national problem and governments have much work to do on prevention. For now, there are steps to mitigate pest-related damage.
The first step is to implement an Integrated Pest Management (IPM) program before a flood occurs. IPM focuses on preventive controls like exclusion, sanitation and maintenance techniques to defend against pest activity year-round. This will help to keep pests away from a property prior to a flood occurring. And if they are eliminated from a property, chances of pest sightings are greatly reduced during and after a flood.
Before this year’s flooding season begins, identify hot spots for pest activity and establish a preventive action plan, as well as a process for minimizing potential damage.
Proactive measures to reduce pest activity and prevent infestations
- Inspect the exterior of a building and seal any cracks or gaps with a durable, water-proof sealant. This type of sealant lasts longer and will help prevent pests from getting inside. Rats, for example, can fit through a hole as small as a quarter.
- Cap or screen floor drains to prevent rodents and cockroaches from entering the facility through the sewage system. Cap or screen unused pipes as well.
- Cover gutters using aluminum or mesh to help prevent leaves and other debris from clogging gutters during heavy rains. Clogged gutters can provide harbourage for pests seeking relief from the wet conditions.
- Identify outdoor areas around a property where water could pool, including ditches, uneven ground, soft ground, burrows and depressions. Drain, aerate or fill these areas with gravel.
- Make sure that garbage compactors sit on level concrete to prevent pooling underneath. Check that lids are closed so water does not build inside, garbage doesn’t wash out, and pests do not seek refuge there.
Reactive measures once water recedes
- Eliminate standing water around the building. Empty or dispose of containers and other objects that hold water. Be sure that any food or product spills are cleaned.
- Remove clutter that can provide pest harbourage, such as cardboard boxes and unused wooden pallets.
- Clean up fallen tree branches, washed-up vegetation or other objects ferried by the flood.
- Inspect wooden structures. Dry or aerate any wet wood to prevent mould, rot, fungal beetles and carpenter ant infestations.
- Inspect the building for structural damage caused by gusty winds or harsh rains and repair immediately to prevent pest entry.
- Be sure dumpsters are tightly closed during the extended time it may take a waste management provider to pick up the trash.
- Inspect, clean and repair gutters that could be flooded with debris.
- Check to see if existing pest control devices are missing or damaged and have them replaced as soon as possible. It may be necessary to increase the number of devices post flooding as a preventive measure.
- Keep pest management in mind if repairs are needed. Pests that infest a property during construction can be hard to remove afterwards, especially if they are sealed in the walls.
After a flood, a property inspection can help assess damage from a pest management perspective. It can provide recommendations for repairs and how to adapt to an existing IPM approach to respond to changing conditions and excess water left by the flooding.
Alice Sinia, Ph.D. is Quality Assurance Manager – Regulatory/Lab Services for Orkin Canada focusing on government regulations pertaining to the pest control industry. With more than 20 years of experience, she manages the Quality Assurance Laboratory for Orkin Canada and performs analytical entomology as well as provides technical support in pest/insect identification to branch offices and clients. For more information, email Alice Sinia at [email protected] or visit www.orkincanada.com.