Earthworks/basement construction in high groundwater areas – any experiences?

Many thanks . That helps me a lot and calms me down a bit.

30l/s is quite substantial. That equals 2,592,000 liters per 24 hours.
We haven't even pumped a third of that amount.

Can you put the pump rate of 30l/s into perspective? Considering our 3 drilling sites/pump shafts, how much can such a line handle at peak?

Reading your logical explanation that the required total pumping capacity decreases over time makes me somewhat more optimistic. Would you confirm that?

If I look at my submersible pump from my cistern... with 120l/min=2l/s... then 30l/s is a lot. And the pumping capacity decreases with lift.

If there is a pump with a C hose attached, one pump is sufficient.

In my opinion, the well shaft works better than a deep drilling.

If there is a pump with a C hose attached, one pump can manage that.

You can’t say that in general. It depends on the delivery height and the pressure of the pump as well as its pumping capacity in general. I had 2x 2 inch (B hose) run up to the distributor. There, 2x B were increased to 1x A and then passed through the meter, and afterwards again through a distributor into 2x B towards the settling basin. As I said, hydraulic calculations have to be made here to answer that.

Can you put the pump rate of 30l/s into perspective for me? Considering our 3 boreholes/pump shafts, how much can such a pipeline handle at peak?

When I read your logical explanation that the necessary total pumping capacity decreases over time, it makes me somewhat more optimistic. Would you confirm that?

In what relation would you like it? I don’t know either the design of the boreholes or the datasheets of the pumps used or the pumping height, etc.

Just stick to the facts:
- well-permeable soil, very low risk of settlement of neighboring buildings
- due to the well-permeable soil, a comparatively economical method for groundwater lowering is feasible.
- The city/municipality has approved the project and does not grant this approval based on “hearsay” but based on corresponding documents.
- A (construction) contractor carries out the groundwater lowering

The only thing that comes to mind: you discharge into a sewer. Are wastewater fees charged for this, and if so, how high are they? In our case, it was billed per cubic meter of water.