Is wastewater drainage possible in the basement?

We will surely find out when the OP reports later.

Rhenish greetings

One of our clients built without a lifting system, and water stood in the basement, about one meter high, about a year after moving in during an extreme rain event. Although or because there is a slope here. There was more water than the sewage system could drain. One year later, it is still being disputed who will pay, but at the moment it looks like the owners are "liable" because the development plan stated that a lifting system should be used for drainage below street level. The costs, trouble, and effort are significant...

And was that with separated rainwater drainage? It can happen if a floor drain is installed and no check valve is fitted. And it is cleaned occasionally. Otherwise, rainwater cannot escape from the toilet, sink, or shower with separate channels.

No separate sewer system, but discharging rainwater is prohibited for the properties here. However, I would be cautious, because instead of "can’t," I would rather say "should not." If it is a requirement to use a lifting system, it is certainly not a hassle, but sensible. Unlike the non-return valve (which can clog and jam faster than you think), such a pipe bend above the backwater level is 100% protection that cannot fail.

I will then report how it really is. But it may take a while. Just wanted to know if someone can tell from the channel plan whether the channel is deep enough for the toilet/shower in the basement to work without a lifting station.

Moin Moin

The possible problem is not recognized here.
It is not only or not just about rainwater.

If the sewer is lower than the drains in the basement, of course everything drains away.
But what happens if the sewer between the house and the inspection chamber or even in the street area is clogged or the wastewater pumping station fails and a backup occurs?
Right.... then, with an installation without a lifting station, sewage-containing wastewater flows into the basement.
Not only your own but possibly also that of the neighbors.
With a lifting station and pumping the wastewater from the basement above the backwater level, the manhole cover on the street or the shaft cover on the property is the lowest point.



Olli