ᐅ Groundwater level too high for a basement.

Sorry, I wasn’t sure which forum this would fit best in.
Here’s the situation...
We did a soil survey in February, and it already showed groundwater at a depth of 1.8m (6 feet). However, because of the basement, we need to dig more than 3m (10 feet) deep. Our immediate neighbors didn’t have any issues with groundwater. They built basements and everything was fine. The only difference is that they started excavation in May/June, while we planned to start in March.
The construction company suggested that to keep costs efficient, we should wait 1–2 months until the groundwater level settles. We suspect there was a lot of rain in January/February.
The builder said we could also pump out the water, but that would add around 10,000 USD in extra costs. Is it really that expensive?
We plan to wait until the end of May, then check again if the groundwater is lower and start construction. If there’s still groundwater, I guess our only option is to pump it out, right?

Or redesign the floor plan without a basement. I would seriously consider that with such a groundwater level.

nordbayer schrieb:

Or redesign the floor plan without a basement. I would seriously consider that with such a high groundwater level.

The strange thing is that just 10m (33 feet) away in a straight line, there were no problems at all. But that was only a few years ago. The same company built 50% of all the houses there and was surprised themselves...

Groundwater at 1.80 meters (5 ft 11 in) is not a problem if you build a waterproof concrete basement ("white tank"). Pumping costs include machinery, electricity, and personnel. It can easily reach 10,000. Earthworks are simply not without surprises.

Keishadow schrieb:

The strange thing is that just 10 meters (33 feet) away in a straight line there were no problems at all.

Not strange. If neighbors’ conditions were the same as your own, all plots would be identical somehow. Somewhere the groundwater begins, somewhere the clay layer. Somewhere underground lies a hill that you only sense at about 1000 meters (3300 feet) depth.
I wouldn’t want a basement with groundwater. What you see when digging will eventually press against your own house – even if a waterproof concrete shell promises security, it still feels uneasy.

What do you need the basement for? Is the plot large enough to create storage space elsewhere?

What does the basement cost, including soil removal (pollution class Z0 or worse?) and pumping out?

Technically, it’s not a big problem with a waterproof concrete shell (white tank) with high monitoring level; the question is only whether it’s cost-effective. Even the smallest material defect can cause long-term issues...