Flood mitigation

Edmonton has experienced flooding caused by intense rainfall events. The impacts of flooding can affect homes, businesses, infrastructure and public spaces throughout the city.

There are four types of flooding that may occur in Edmonton:  

• Overland flooding: Overland flooding occurs when rain falls faster than the ground or sewer system can absorb it. Water can collect on streets, sidewalks, parking lots and low-lying areas, potentially causing damage to homes, businesses and infrastructure.
• Sewer surcharging: Sewer surcharging occurs when the stormwater system reaches capacity during heavy rainfall. When this happens, water levels in the sewer network can rise and increase the risk of basement flooding or sewer backups.
• River flooding: River flooding can occur when significant rainfall and runoff throughout the North Saskatchewan River watershed increase river flows and water levels. If river levels rise high enough, water may move beyond the riverbanks and affect nearby properties, infrastructure and areas within the river valley.
• Groundwater flooding: In times of heavy rainfall, the groundwater table can rise and potentially increase the risk of basement flooding. Groundwater flooding is caused by water travelling through the ground, not over the land. Efforts are underway to better understand groundwater in Alberta.

Edmonton's stormwater system is designed to manage typical rainfall events and help reduce the impacts of larger storms. During unusually intense or prolonged rainfall, however, the amount of water entering the system may temporarily exceed its capacity, resulting in localized flooding or delays as water moves through the drainage network.

Learn more about Edmonton’s drainage system design standards.

We've been actively addressing stormwater flooding through EPCOR projects in higher-risk areas across Edmonton while also supporting residents and customers in private property mitigation. 

Capital flood mitigation improvements have been completed in several Edmonton neighbourhoods, with additional projects currently underway across the city. For a list of current projects, visit Edmonton Construction Projects.  

Low Impact Development (LID) or green infrastructure, is an approach that helps manage rainwater where it falls through features such as rain gardens, bioretention areas and other green infrastructure. Programs like the RainWise Rebate Program help residents take part in these solutions on their own properties.

EPCOR also offers programs and services that help residential, multi-residential, commercial and institutional property owners better understand and reduce their flood risk. These programs include the free Flood Prevention Program and the Backwater Valve Subsidy Program.

We're also creating a smarter stormwater network that will allow us to anticipate and react to storms in real time using monitoring and control technology, and will optimize existing stormwater management infrastructure.  

Our Stormwater Integrated Resource Plan (SIRP) guides our flood mitigation work across Edmonton. The plan focuses on five interconnected approaches to reduce flood risk: SLOW, MOVE, SECURE, PREDICT, and RESPOND.

The plan was originally presented in 2018 as a framework of a 20-year, $1.6-billion plan that addressed flooding risks from health and safety, environmental, social and financial perspectives. The original plan is detailed in the May 2019 Utility Committee report.

Every Edmontonian can help our city reduce its flood risk. Whether you own a home, operate a business or simply want to help your neighbourhood recover after severe weather, small actions can make a difference.

Here are some steps you can take to help protect your property and community.

Regular property maintenance can help reduce the risk of flooding and water damage. 

• Clean and repair your eavestroughs and downspouts
• Maintain your window wells and check if they’ve been properly installed
• Clean and check sump pumps and weeping tiles annually 
• Use rain barrels to reduce the amount of water flowing on your property
• Clean debris from backwater valves to prevent sewage from flowing back into your basement.
• Install a backwater valve to prevent sanitary sewer backups
• Seal foundation cracks to prevent groundwater infiltration
• Prevent water from pooling by ensuring your property slopes correctly away from your home

For more information, visit Flood Prevention at Home or read The Homeowner’s Guide to Lot Grading and Drainage.

Our Flood Prevention Program provides eligible Edmonton residents with a free property assessment conducted by trained flood prevention advisors.

During the assessment, we'll help you:

• Identify flood risks specific to your property
• Understand ways to help reduce those risks
•  Learn about available EPCOR programs and supports
• Determine whether you may be eligible for additional flood prevention measures

Help to protect your home from a sanitary sewer line back-up by installing a backwater valve. Our Backwater Valve Subsidy offers financial assistance by providing up to $800 for the installation of an interior or exterior backwater valve.

Note: homes built after 1989 are required to have a backwater valve; anything prior to that year may not have one.

The RainWise Rebate Program makes it easier and more affordable for Edmonton residents to protect their properties from flooding and reduce flood risk in the community through effective stormwater management.

If you are a property owner or renter in Edmonton, you may be eligible for rebates from EPCOR on projects that help manage stormwater on your property.

Small actions can make a big difference during heavy rainfall. By helping water move where it's supposed to go, residents can help reduce localized flooding and protect their neighbourhood.

• Help keep catch basins clear. If it's safe to do so, remove leaves, debris or other materials that may be blocking nearby catch basins and preventing water from draining properly.
• Keep swales on your property clear. Swales help direct stormwater away from homes and into the drainage system. Avoid filling them in, blocking them or allowing debris to accumulate.
• Report drainage concerns. If you notice a blocked or frozen catch basin, drainage issue or localized flooding concern, contact EPCOR or call 311 so it can be investigated.
• Stay back from stormwater ponds. Stormwater ponds and dry ponds fill up during a heavy rain to protect your neighbourhood from flooding. Water levels can change fast and the edges aren't as stable as you think. They are not safe for recreation.