FAQ

A backwater valve is a mechanism installed on the main drain that closes when the level in the municipal sewer rises, stopping it from backing up into your basement. It matters most in houses where the basement drain sits lower than the street sewer, which is common in flat areas built before 1970.

Camera inspection alone, with a video report, generally runs $250 to $450. If cleaning is needed first to see the inside of the pipe clearly, add the cost of that cleaning. The exact price depends on the drain's length and how easy it is to access.

A slow drain that gets worse after every rain, an auger that snags at the same distance every time, or a recurring sewer smell are typical signs. Only a camera inspection confirms roots are present and shows which joint they got in through.

Some cities and boroughs offer financial assistance for a backwater valve, but the criteria and amounts vary and change from year to year. Check with your own city or borough before the work rather than relying on a figure found elsewhere.

Cut power to the affected area if it's safe to do so, avoid walking in the water without waterproof boots, and photograph the damage before you start cleaning up — furniture, boxes, walls, the waterline on a door or wall. Those are the things an insurer generally asks for to process a claim.