Lowering of groundwater according to soil report - Your experiences?

When the pump is running, and a [Pegellatte] shows you that the water level has not dropped in 3 days, you can still install a second pump

The route to the channel (approx. 25m) runs through the parental property and is therefore uncritical

If the parents live there, you also have daily supervision to check if "everything is running," we had that too and it is worth its weight in gold.

If the parents live there, you also have the daily control whether "everything is running," we had that too and it is worth its weight in gold.

Can you still remember how high the costs regarding authorities were and how many days in total you had to pump? You probably don't remember the subsidized cubic meters anymore :) That would still be interesting. I found a website that offers various construction formulas for calculation purposes. There I entered the data from the soil survey and the tool spits out a water volume of 39.55 m³/h. That would mean I have to size the pump a bit larger. We just went for a walk and looked at an excavation pit down the street that is enclosed with sheet piling and even there a fairly large submersible pump hangs about half a meter deep in the water trench. They are building an underground garage close to the property boundary, so full program and thus not quite comparable. We hope the weather is on our side and the groundwater already stands as low as possible during excavation.

I would have the pit for the basement excavated and drive 2 lances for suction wells into the ground. The idea with the drain pipe is good, but I can only imagine it if the pipe is at least 1.2-1.5m below the basement slab.

I can answer your question about the basement. I have had no problems with leaks for 20 years. The architect/site manager and I have also been meticulous to ensure that the basement was built exactly according to plan. I then installed a drainage under the basement shafts as a precaution, in case the groundwater rises higher than planned.

I then laid a drainage under the basement shafts as a precaution in case the GW should rise higher than planned.

we had that several times already, then the water flows from the drainage into the basement light shafts :oops: . So we closed the basement light shafts, placed the pump inside the vertical drainage pipe, and pump for 2-8 weeks until the GW has dropped again.