What is the best way to install inside flood control?
The city sewer backed up last September and flooded our basement with a foot of rain water. I want to prevent that from happening again, so I'd like to install some sort of flood control. I've been given several different options by several different plumbers, but none of them could really state why their method was the best.
1) External flood control in front yard - $7000
2) Internal flood control connected to catch basin - $3500
3) Internal flood control connected to "stack" - $3800
I like option 1 because I understand it, but it's so expensive! Also, since the sump pump is in the front yard, we would have no way of knowing when it failed until it backed up.
It's the other two options that I don't quite understand. In both cases, the plumbers said they would redirect all our basement plumbing (the floor drain, the basement sink, etc.) to a new sump hole and pump everything out. There would be no backup because the pump out line would have a valve on it. But one guy said he'd have it pump back out to the catch basin, and the other guy said he'd connect it to the "stack".
Is there any reason one method is better than the others?
I'm concerned about too much water collecting in the catch basin - it is only 3 feet from our back wall and that wall already has a lot of seepage. And I don't understand the stack at all - where does that go? Does it connect to the main sewer line below our house? And is there a problem with having the valves inside? One plumber said he'd go with the external flood control because if water fills the sewer line that runs under our basement the pressure could crack our floor!
I have asked all of them to explain why their method is better, but none of them seems to be able to explain it very well.
Any help would be greatly appreciated!