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Flood Proofing Program

In the 1960s, The Don Mills Channel was realigned and confined to a relatively narrow corridor through urban development.  The current system of open channels and culverts does not have enough capacity to handle storm water runoff during large storm events causing floods in the area of both businesses and major roads.

1954 FLOOD MAP
Don Mills Channel Area in 1989 developed

 

 

 

 

 

 

 

 

 

 

 

 

To help property owners and tenants within the area withstand larger storm events, the City of Markham is developing a Flood Proofing Program. This program will help owners and tenants identify site-management and flood proofing measures that can help protect their properties and assets from damage. Through this program, the City has researched various site-specific options for commercial properties including manufactured products, buildings modification, emergency preparedness planning, and other practices.  

 

Know Your Risks

Businesses surrounding the Don Mills Channel (DMC) have flooded numerous times after heavy rainfall. Major roads in the
DMC area, including Woodbine Avenue, can also be impassable during severe storms.

The reason this area is at higher risk of flooding is its limited capacity for carrying floodwater. The current system of storm
sewers, open channels, and culverts was designed in the 1960’s to carry moderate storm events. The system does not have
adequate capacity to handle stormwater during intense rainfall events. 

Damage to property and assets may occur during severe thunderstorms and flooding.

flood images from Markham
Image of flooding in a parking lot in the Don Mills Channel area
Be Prepared

You can take the following steps to prepare for a flood and reduce the likelihood of damage

Before a Flood:

Flood Preparedness and Response Plan

Develop an emergency preparedness and response plan for your property and share it with your employees. 

Review the City of Markham’s flood emergency preparedness recommendations and the TRCA’s flood preparedness tips to make sure you are protecting your business from damage.

See here for a template and instructions on how to complete your Flood Emergency Response Plan.

Here are some key items in the preparedness and response plan for flood emergencies:

1Plans to relocate critical contents into higher floors, taking into account the time and attention needed to move such contents safely. Hazardous materials should be relocated or sealed.
2Notification to car owners to avoid parking their vehicles in flood-prone areas.
3Evacuation plans to ensure that occupants are not stranded in the building, including driving routes to avoid flooded roads.
4Turn off power, gas, and water at the main switch.
5Ensure sump pump is working; have a battery back-up.
6Clear eaves troughs, catch basins, culverts and drainage ditches.
7After the flood, do not enter your business until municipal authorities state it is safe to do so.
8Check building for foundation damage and make sure all overhangs are supported.
9Contact professionals for basement dewatering, cleaning of contaminated material and servicing appliances.

Additional resources are available at York Region’s Business Continuity Template and Flooding: Health, Safety and Environmental Issues Fact Sheet.

 

Flood Insurance

Review your insurance policy to ensure you are adequately covered, and ensure your insurance coverage includes sewer back-up provisions. Visit the Insurance Bureau of Canada: Disaster – Water for flood protection and insurance tips.

The City of Markham has made significant infrastructure investments in flood control improvements, which will help protect public and private property and will make critical infrastructure more resilient to extreme weather. Markham is challenging the insurance industry to consider these changes as part of the insurance rate setting.  You are encouraged to share information about the City’s flood mitigation work with your insurance agents as part of their policy renewal discussions.

 

During a Flood:

Remember that lives are more important than property. This is why sharing your Flood Preparedness and Response plan with all employees is key prior to a flood event. Key phone numbers and contacts to reach during a flood can be found on the back of this brochure.

 

After the Flood and Recovery:

  • Do not enter your business until municipal authorities state it is safe to do so
  • Check building for foundation damage
  • Contact professionals for basement dewatering, cleaning of contaminated material and servicing appliances

If you have costs related to a natural disaster, visit The Disaster Recovery Assistance for Ontarians program to see if you qualify for assistance.

Stay Informed

Flood Information Sources

  • Environment Canada issues Special Weather Statements when heavy rainfall has the potential to cause local flooding.
  • You can also sign up for flood forecasting and warning messages at www.trca.ca/get-flood-messages.  These messages range from water safety statements, early notice of potential for flooding to flood warning when flooding is occurring or is about to occur.

Follow social media alerts and notices for extreme weather events that may result in flooding in the Don Mills Channel area:

Who to Contact during a Flood

If you are in danger or there is a threat to life and safety, call 911 immediately.

  • To report sewer back-up, localized flooding on municipal roads, blocked catch basins or other municipal infrastructure, call the City of Markham at 905.477.7000. 
  •  For hydro-related questions including safety tips for flooding, call Alectra’s Customer Service at 1.877.963.6900 and Press 2.
  • To report river flooding, call TRCA floodline at 416.661.6514.

If you see any potential property damage, call your insurance representative as soon as possible.

Flood Proofing Techniques

Floodproofing Techniques

Below is a list of techniques that are available for flood proofing commercial properties along with fact sheets explaining each technique in more detail.

Building Modifications:

Site Modifications:

Owner / Tenant Responses:

Owner / Tenant Practices:

Site-Investigation and Recommendation:

As part of this program, the City has completed site investigations and a flood risk assessment for eligible properties.