Flooding and Drainage Repair in Abbotsford: Sumas Prairie, the Dikes and Your Own Lot

Three kinds of water, three responses

Regional flooding, when the Nooksack or the Fraser rises or the prairie drainage cannot keep up, is a matter of the City’s dikes and pump stations, the province’s flood programs and evacuation orders, and your insurer; no sump pump answers it. Groundwater is what most Abbotsford homeowners actually deal with: the winter water table rises, perimeter drains silt up, and water appears at the basement wall-floor joint or in the crawlspace. Sewer backup arrives from below, through the floor drain, in heavy rain in the older parts of the city, and smells like sewage.

Photograph where the water first appeared and when. On the flats, look at the ditch in front of the house; if it is full and not draining, the problem may start at the road.

What the City owns and what you own

The City of Abbotsford owns and maintains the dikes, the Barrowtown pump station and the network of ditches, canals and culverts that drain Sumas Prairie and Matsqui Prairie, and the storm and sanitary sewers in the urban areas. If a roadside ditch or a culvert under your driveway approach is blocked and flooding your frontage, report it to the City. Everything inside your property line is yours: the perimeter drains, the sump if there is one, the crawlspace and the grading. Rural properties on the prairie often drain to private ditches and field tiles that connect to the City system, and keeping those clear is the owner’s job.

Since 2021 the City has been working through dike and pump-station upgrades and flood-plain mapping. Those affect what can be built where; ask the City before planning an addition on the prairie.

Fixing what is yours

For groundwater, a drainage contractor should inspect or camera the perimeter drains, flush or replace silted sections, install a sump and pump where the lot cannot drain by gravity, and, in a crawlspace, lay a sealed vapour barrier over the soil. For sewer backup, a plumber installs a backwater valve on the sanitary lateral; while it is closed nothing in the house drains, so do not run water during a storm. Extend downspouts well away from the foundation and make sure the ground slopes away from the house before spending on anything underground.

Rural homes on wells should have the well head sealed and above grade; a flooded well needs to be shocked and tested before the water is used again, and Fraser Health publishes the procedure.

• Photos of where the water appeared and when
• Condition of the roadside ditch and driveway culvert
• Perimeter drains inspected by camera
• Downspouts extended away from the foundation
• Insurance: sewer backup and overland water coverage checked

Insurance and contractors

Sewer backup and overland water are separate add-ons on a BC home policy, and overland flood coverage is not offered at every Abbotsford address; after 2021 some insurers withdrew it on the prairie. Check what you have before the winter rains, and photograph the basement now. The province’s disaster financial assistance program applies after a declared event, with limits.

Drainage work is unlicensed in BC. Ask for a certificate of liability insurance and a WorkSafeBC clearance letter, and for a written quote that states what was inspected, what is being replaced, where the water will go and the warranty. Excavation near a dike, a ditch or a City easement needs the City’s approval.