Single or two-family house with a hole in the basement

Good day everyone,
we are about to buy a house built around 1955 (unfortunately there is no more building description - also not at the building authority).

The house has a basement, where there is a hole about 40x40 CM and about 1 meter deep.

Water flows there and a pump hangs inside. According to the owner, the pump runs about 1-2 times a year. Next to the house runs a small stream. The neighbors said that even when it rains it does not become a rushing river.
The basement is dry and the exterior walls are dry as well.

I am a bit uncertain whether something like this can cause problems and have one or two questions.
The water is currently flowing.
Can I reuse the water and use it for toilet flushing?

How do you "remediate" such a hole?

Thank you very much for any tips.
Regards
Christian

The pump sump is probably an infiltration shaft; does the pipe come from the roof drainage, the light wells, or something similar? Or is it gray water from a sink or from the washing machine?

"Renovate": well, the floor should not become muddy so that the water can drain away. And I would regularly test the pump. It should then start when the water cannot drain quickly enough. In the past, there were no white tubs and the water surrounding the basement could collect and infiltrate there, keeping the walls relatively dry.

so completely independent of this hole, which I find very unpleasant but cannot justify objectively (except with: which reasonable person would want a hole in the basement):

I would take a closer look at the "small stream," look for flood maps, see where it flows, which bodies of water are nearby and what the drainage possibilities are (map with contour lines).
Because whether you believe in climate change or not, the weather is changing, and heavy rainfall events are becoming more frequent.
I would be very interested to know if trouble threatens me from that side.

The pump sump is probably an infiltration shaft; does the pipe come from the roof drainage, from the light shafts, or something similar? Or is it greywater, from a sink or from the washing machine?

"Renovate": well, the floor should not become muddy so that the water can drain. And I would run the pump regularly for testing. It should turn on if the water cannot drain quickly enough. In the past, there were no white tanks and the water surrounding the basement could collect and infiltrate there, keeping the walls relatively dry.

Hi Scout thanks for the assessment.
No, it is not roof drainage. It is probably a water source/vein?

A hose goes from the hole into the shaft and from there into the sewage according to the owner.

I have uploaded a video, maybe you can see it better here.

[MEDIA=YouTube]oWTctLJkUmg[/MEDIA]

Many thanks and best regards
Christian

My parents have [also], but no small stream!! I would interview the neighbors to find out how often the stream causes problems! The climate is messed up, maybe you constantly have problems

A natural hazard or flood insurance is then rather pointless with the stream next door. I would consider that in times of tornadoes in the suburbs.