Sumas Prairie Flood Mitigation Options to be Presented to Council


City of Abbotsford staff will be presenting flood risk reduction and mitigation options to Abbotsford City Council for their information on April 4, 2022, as community engagement with residents, businesses and neighbouring governments commence.

Following the devastating floods in November 2021, the City of Abbotsford has been working with engineering consulting firm Kerr Wood Leidal, to develop a long-term flood mitigation plan for Sumas Prairie. Through the plan, the City is considering different options designed to enhance the City’s existing flood related infrastructure and reduce flooding impacts to residents and the community.

The options being presented to Council have been developed for discussion with residents, businesses, governments and stakeholders. Options range in cost from an estimated $209 million to nearly $2.797 billion and offer a range of flood mitigation and protection measures for residents and businesses of Sumas Prairie.

  • Option 1: Status quo with enhancements to Barrowtown Pump Station.
  • Option 2: Status quo with enhancements to Barrowtown Pump Station and a new Sumas River pump station.
  • Option 3: Added floodway and storage area, enhancements to Barrowtown Pump Station and a new Sumas River pump station.
  • Option 4: Added narrow floodway, enhancements to Barrowtown Pump Station and a new Sumas River pump station and more.

Options provide varying levels of enhanced flood mitigation compared to current infrastructure in place. The City of Abbotsford needs to take immediate action to implement a solution within our municipality so that our community is not as significantly impacted when future weather events occur.

Over the coming months, Abbotsford residents, businesses, and neighbouring governments will have the opportunity to learn more about each option and share their feedback on what matters most to them. The City of Abbotsford recognizes some of the options may cause people to have questions about potential impacts to their property. City of Abbotsford staff have proactively reached out to Sumas Prairie residents and businesses will be engaging directly with them over the coming weeks to discuss and gain their feedback and input. Additionally, the City of Abbotsford is committed to hearing from the entire community on what is most important to them. All residents are encouraged to visit Let’s Talk Abbotsford to provide their feedback and sign up for engagement opportunities.

The City of Abbotsford has also begun it’s intergovernmental conversations with Semá:th, Màthexwi and Leq’á:mel First Nations leadership. Provincial and Federal governments, City of Chilliwack, Fraser Valley Regional District, and Whatcom County, Cities of Everson and Sumas in the Washington State in United States, will also be engaged.
The City of Abbotsford will use the feedback we receive to identify a preferred flood mitigation option and complete the long-term flood mitigation plan. The plan will be used to inform funding discussions with senior levels of government.

Background information:

In November 2021, Abbotsford experienced one of Canada’s largest flooding disasters when the Nooksack River overflowed and breached its dyke and floodwater headed straight to Abbotsford, flooding Sumas Prairie. This event forced the closure of the US/Canada Border and Highway 1, effectively stopping the flow of people, goods and services and led to a significant loss of livestock and poultry, as well as the evacuation of over 1,100 properties and over 3,300 people from their homes.

The flood protection system in Sumas Prairie is designed to protect against flood risks from the Fraser River freshet (in Spring) and Nooksack River overflow (in Fall). This system includes Sumas River/Vedder dykes, Barrowtown Pump Station and flood boxes. The Barrowtown Pump Station operates all year to drain water from the former Sumas Lake Bottom via the Sumas Canal. The flood boxes allow water to be moved from the Sumas River into the Fraser River and must be closed when downstream rivers are high to prevent backflooding into Sumas River.

Currently, when the Nooksack River overflows its banks, the water floods adjacent land and flows towards the flood boxes on Sumas River in Abbotsford. If these flood boxes are closed due to the water levels of the Fraser and/or Vedder rivers, water is held back and can flood properties as demonstrated by the latest atmospheric events. Depending on the volume, water can overflow the Sumas Dyke into the former lake bottom area of Sumas Prairie. The November 2021 rainfall in Abbotsford was estimated to be approximately a one in 100-year event.

Due to increased weather events and impacts from climate change, more flood events could occur if improvements are not made. The flood mitigation options explore how to store and spread the volume of water to different areas of the floodplain and guard against different levels of flooding. Options 3 and 4 meet the flood protection guidelines in B.C., which are to support a 1-in-200 year event with climate change. These options are an important initial step in the City of Abbotsford’s effort to discuss how to manage the impact of future floods to properties and reducing the risk of repeating the devastation experienced this past year.


To learn more about the options and engagement on Abbotsford flood mitigation, visit:

For more information contact:

Aletta Vanderheyden Communications and Public Relations Manager
City of Abbotsford