Abbotsford council is considering four options, ranging in cost from $100 million to $2.3 billion, to prepare the city for the next major flooding event on Sumas Prairie.
Among the options is the city acquiring properties in the floodway and designating them only for flood-resistant crops.
The flood-protection plan was presented at council’s committee of the whole meeting on Monday (April 4) and now moves to the community-engagement process.
The city has been working with engineering consulting firm Kerr Wood Leidal to develop the project.
Mayor Henry Braun emphasized that the plan is in the initial stages, and the fine details – including how it will be funded – will be worked out later.
He said he has had numerous discussions with senior levels of government, stressing the need for their financial support.
“They are well aware of the magnitude of the costs. This has to be done,” Braun said.
Rob Isaac, general manager of engineering and regional utilities, told council that the series of atmospheric rivers and the overflow from the Nooksack River in Washington State last November sent approximately 29 million cubic metres of water across Sumas Prairie.
This was a one-in-100-years event in a diking system designed to handle a one-in-35-years event, council was told.
Provincial guidelines call for flood-mitigation infrastructure to be built to withstand a one-in-200-years event.
Only one of the four options being considered – and the most expensive – would meet those standards.
The first option involves maintaining the status quo, with some improvements to the Barrowtown pump station.
Dike breaches that were temporarily fixed in November would be permanently repaired, and all the low spots along the dike would be filled.
The projected cost is $100 million, providing protection for a one-in-35-years event.
Option 2 builds on that by adding a new Sumas River pump station. The total estimated cost is $800 million, with flood protection for a one-in-50-years to a one-in-100-years event.
Option 3, estimated to cost $2 billion and providing protection for a one-in-180-years event, includes everything in options 1 and 2, but would also involve reinforcing and raising some of the existing diking system and relocating and setting back part of the Sumas River dike.
As well, new dikes would be constructed, including to protect the Huntingdon area and the industrial area around Riverside all the way to Highway 1 and along the right bank of Saar Creek and along the border.
Highway 1 would be raised for a portion, but there would be no flood-protection improvements to Southern Railway.
Option 4 adds to the previous three options by also raising the railway; adding other pump stations at Marshall, Saar and Arnold creeks; and creating a new dike on both sides of the Sumas River and along the border in west Sumas Prairie.
This option is estimated to cost $2.3 billion and provides protection for a one-in-200-years event.
“This option provides the largest number of protected properties out of all options,” said Stella Chiu, acting director of utilities infrastructure.
Both options 3 and 4 would include the acquisition of properties in the floodways, with the land then being used for flood-resistant crops, and covenants put in place to prohibit building. The plan doesn’t indicate what those crops would be or what specific properties would be impacted.
But Isaac said any farmers affected would be “made whole” by the property acquisitions, and fewer properties would be impacted in option 4 due to greater flood protection than in option 3.
Additional costs under consideration for each option are $32 million for flood-protection upgrades to Clayburn Village and $77 million for water-source resiliency. Isaac said the November floods resulted in the primary water source at Norrish Creek being out of commission for two months.
An additional cost under consideration for options 2 to 4 is $388 million to enhance the Matsqui dike.
These additional costs put the total range of the options from $209 million to $2.8 billion.
The city’s engagement process now includes discussions with the public, First Nations, senior levels of government, Washington State, the City of Chilliwack and the Fraser Valley Regional District.
More information about the options and an opportunity to provide feedback are available at letstalkabbotsford.ca.