ᐅ Are backwater valves always necessary in flood-prone areas?

Created on: 22 Jan 2018 22:41
M
McEgg
Since we are currently planning the plumbing, I brought up the topic of backflow preventers. We have three points in the basement where wastewater is discharged outside. For some reason, they didn’t channel everything to one location...

The plumber says that backflow preventers are not planned for our system. Apparently, they are only required if rainwater is also discharged into the sewer system. In our case, this is not allowed, meaning only wastewater goes into the sewer.

Since we are building in a flood-prone area, I believe it is still possible that water could back up through the sewer system.

What do you think? Wouldn’t I need backflow preventers after all?
P
Pädda
27 Jan 2018 12:14
What does it look like when building without a basement? Do you even need a backwater valve in that case?
McEgg27 Jan 2018 12:34
As far as I understand, no. You don’t have any openings below the backwater level. It would be different if you were building your floor slab below the backwater level, but that would probably be unwise and, I believe, not permitted. At least not in our area.
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Baumfachmann
28 Jan 2018 00:58
In most cases, not with a slab foundation