Possible building plot - shaft on the property

First of all, the idea with the rod is not bad. You always need a measuring level where you want/must check groundwater. This indicates a high groundwater level. For building on a slab, it doesn't mean much yet. With a basement, the costs are significantly higher. Just ask the responsible waterworks and/or building authority. Someone there should be able to give comprehensive information. And of course, the owner should also know.

Then I will definitely “arm” myself with a latte for the next visit.

I will also try to get some information at the local building authority. However, it is probably uncertain whether I will receive an answer from there in the near future considering the Corona situation. Additionally, the real estate market in our area (Greater Frankfurt) is extremely tense, meaning the seller dictates the pace and wants to go to the notary as quickly as possible (and does not want to provide any warranties for anything), so I can only rely on their statement to a limited extent.

Regarding groundwater: about 200 m away from the shaft (as the crow flies) a small stream flows parallel to the narrow side of the property; however, the terrain slopes slightly downward from the property to the stream, according to Google Earth there is a height difference of about 4-5 meters between the shaft (i.e., the cover in the photo) and the stream. On the other side of the stream, the terrain slopes downward for another approx. 100m (about another 3-4 meters in height) before it slowly rises again. Between the property and the stream there are also houses, wouldn’t they also be affected by any potential groundwater issues?

Hello BananaJoe

do not confuse a stream with groundwater. They have nothing to do with each other. I do not consider it likely that this is a well. Measure how deep the shaft is. And if you want to know for sure, pump out the shaft. Someone among your acquaintances must have a sewage pump. Otherwise, you can rent one for 20 euros at a tool rental place.

Steven

It's clear that the owner wants to sell quickly. But at least he must be able to provide information. And he should do so, otherwise the seriousness of the deal is also questionable.

So, after the sun made another appearance this afternoon, I spontaneously went for a walk with a latte.

Upon closer inspection, I was able to observe the following:
- The shaft is located about 20m away from the road providing access to the property (the road was only laid out in 2019, before that the area was agricultural or, as I was able to find out, used as a small allotment garden settlement)
- The thing is made of concrete, not masonry (see pictures)
- It is not just a vertical shaft, but also has a horizontal channel branching off in one direction (if relevant: towards the road = the direction where the stream is)
- The water level is about 1.40m below the ground surface/shaft opening and the water is quite clear
- The water has a depth of over 1.20m – how deep exactly, I couldn’t find out because my latte was too short (please no jokes )
- The upper edge of the horizontally branching channel is just under 1m below the shaft opening
- A few centimeters below the water surface there is presumably a (horizontal) pipe or something similar; in any case, I was able to rest my latte on it

What has less to do with the shaft itself but is also confusing to me:
- In the drainage plan of the street, which was also created in 2019, neither the shaft nor the channel nor anything else is marked on the property

All this leads me to the following questions:
- If the thing was installed by the city, it should have appeared in the drainage plan, right?
- Are there usually sewer plans that provide a complete overview (in case I cannot reach anyone at the building authority due to Corona)?
- Can this thing spoil house construction without a basement? The vertical shaft, as mentioned, is outside or possibly at the rear end of the building window, but the channel, if it extends to the street, would run directly under the house...
- Which service provider can especially answer the last question? A geologist who also prepares soil reports? Or is there something more specialized?

Many thanks for all previous and hopefully future answers!

Hello

Could it be that the stream was "tapped"?
Both agriculture and allotment gardens always need water.
In an emergency, let concrete run in. End with a shaft.

Steven