When Environment Canada warns of an atmospheric river, the Lower Mainland can get days of heavy rain on ground that is already soaked. That's when sump pumps fail, floor drains back up and perimeter drains overflow. An hour of checks before the rain arrives prevents most of the basement calls we get during these storms.
Before the rain: the checklist
- Test the sump pump: pour a bucket of water into the pit and make sure the pump starts, empties the pit and shuts off.
- Check the sump discharge line outside: it should be clear, not frozen or crushed, and send water well away from the foundation.
- Look at the backwater valve if you have one: open the cleanout cap, make sure the flap moves freely and nothing is stuck in it.
- Pour water down the basement floor drain: it should drain quickly. Slow or gurgling means a partial blockage worth clearing now.
- Clear gutters and downspouts, and make sure downspouts empty away from the house or into a working drain.
- Clear leaves off the catch basin or yard drain grates on your property.
- Move valuables, paperwork and electronics off the basement floor.
- Know where your main water shut-off is and make sure it turns.
During the storm
- Keep an eye on the sump pit and the floor drain, especially overnight.
- Cut water use if the floor drain starts to gurgle or seep: laundry and long showers send more water into a line that may already be full.
- If water is coming in, keep clear of electrical outlets and equipment in the wet area.
If water starts coming in
Water coming up through the floor drain usually means the sewer or storm side is backing up; see our guide to a basement floor drain backing up. Water coming through the walls or floor near the edges points to the perimeter drains or the sump. A sump that runs nonstop, or doesn't run at all with water in the pit, needs attention right away; our sump pump troubleshooting guide covers the checks.
For backups, sewage or a failed sump pump, call. We handle sump pump repair and replacement, drain and storm drain cleaning and sewer backups 24/7.
Common questions
Does a backwater valve stop all basement flooding?
No. A backwater valve stops sewage from the city line coming back into the house. It does nothing for groundwater coming through walls or the floor; that's the job of the perimeter drains and sump pump. Our post on backwater valves explains the difference.
How do I know if my perimeter drains are working?
Water seeping in where the wall meets the floor during heavy rain is the usual sign they're blocked or failed. See our post on perimeter drain problems.
Who do I call if my basement starts flooding?
A plumber answers (604) 870-1442 24/7, and every job starts with a free estimate.