SANDY - My Checkvalve Failed Me - What went wrong

[chefwong]

We got flooded last year - and part of the renov included gutting up the floor and installing a checkvalve from the street sewar.
In Hindsight, I would have also installed a ball valve right behind that.

So Sandy has come and gone.
Unfortunately, we lost power as well.
The checkvalve did not work at all as we got backup that just coming and coming......
I wad hauling out 5 gal buckets until 3 AM
I hesitated on owning a generator (just due to infrequency of usage - maybe 1X every 3 years) but since have gone ahead and ordered one...

I still have a couple of days....till I pry the cover open to check the door operation, but if anyone can shed some light aside from something restricting the door from closing....as to why it would have failed/let water past the door, I'd love to hear some feedback.

And OR advisable solutions on whatever other plumbing things I could do to prevent the water backup.
Regardless of Sandy or not, it seems more reoccuring that if we get HEAVY water in a short amount of time, the city sewars just can't keep up.
It's not localized to my property but everyone on the block.

[hj]

There could be many possibilities. Some plastic checkvalves use a flexible rubber gate and hinge. After a fairly short time period, the rubber hinge hardens and/or the disc distorts, so it either cannot close, or seal if it does close. In addition, ALL backwater valves will fail if ANYTHING lodges in the opening so it cannot close tightly. You should only count on a backwater valve slowing the flooding down, and have a backup plan to deal with the water that does get by it. When I was in the Chicago area, we installed combination backwater valve and pump systems to take care of both problems.

[chefwong]

Do you suppose a camera check would be beneficial ?
I'm going to assume the entire block is tied to the main pipe.

My next door to my right, 4 houses to my left all flood.
The STRANGE thing is the 2nd house to my Right - Nary a drip of overflow !

[hj]

Old thread, but because of the laws of physics, water will fill the lowest vessel and you and your neighbors are probably lower than the one who did not flood. He should probably buy you a beer in gratitude for protecting his house. If you had NOT bucketed out the water, he would have eventually flooded also.