ᐅ Old basement from 1910 with water drainage shaft

Hello,

We have purchased a house built in 1910.

The basement is completely dry, which is already a positive sign.

In the basement, there is this opening, fully tiled except for a 2 cm (1 inch) gap where a gravel bed is located. The water inside is also very clear. What could this be? According to the seller, the water has always been used for irrigating the garden. I’m concerned that it might overflow since there is no pump or similar system installed.

The building is situated on a slope, and one side is only 0.5 m (20 inches) below ground level. It should therefore be considered a high basement.

Unfortunately, the photo is too dark and does not show any details. Investigating such hydraulic conditions is an analytical task that can only be carried out on site, taking into account all potentially related factors: topographical conditions, soil composition, soil permeability, groundwater level, etc. A lot of information needs to be researched or newly collected.

In your case, it could either be an old well or a type of "sump pit" where water accumulates, entering through water-bearing layers in the specific slope towards the house—possibly only during heavy rainfall events. If the basement is only a partial basement, and furthermore just a so-called "crawl space" with a height of only 1.20–1.50 meters (3.9–4.9 feet), this would indicate that the groundwater level might be relatively high.

Based on the description, I would also consider it to be an inspection chamber, which obviously serves to pump water away during heavy rain events. You might possibly have a high groundwater or perched water table? As mentioned before, this remains speculation. However, in our street, we also have several basements with these types of openings because we are built on clay/marl soil, and during heavy rain, water is pushed up against the old basement floors from below.

In this context, a word of caution about pumping water away: doing so can often lead to drawing in new water under the house, which may have unpredictable consequences for the surrounding soil stability.

I will take better photos of the opening etc. later. Regarding the groundwater level, unfortunately, there is no information available from my local authority.

It is simply a constant water level.

walkers schrieb:

It's always a constant water level.

How long have you been living in the house? 20 years? Have you experienced multiple heavy rain events and monitored the water level each time?

No. You have no idea how the water level varies from summer to winter, from dry periods to heavy rainfall. Therefore, you need to a) show more photos and especially b) keep an eye on the shaft over the coming months and years.

nordanney schrieb:

How long have you been living in the house? 20 years? Have you experienced multiple heavy rain events and always checked the water level?

The house was only recently purchased.... However, the seller didn’t specify exactly what it is. The only thing he mentioned was that he always used it for garden irrigation. So that's basically the question here...