ᐅ Installing a cistern by lowering it into the ground after initial placement

Dear community,

I built my house 2 years ago and have a soakaway pit in the garden to manage rainwater drainage. The dimensions are approximately 7 meters (23 feet) deep and 3 meters (10 feet) in diameter. At the top, it narrows to an 80cm (31 inches) concrete ring with a cover. The bottom is filled with gravel, and the pit itself is made of concrete rings.

I would now like to convert it into a kind of rainwater cistern to reuse the water, as currently it just soaks away into the ground (gravel).

Do you have any ideas on how to install a container inside the pit to collect the water so that I can then use a submersible pump to water the garden, wash the cars, and so on?

Thank you very much

Hello Markus,

try searching online for a concrete cistern. I bought one from a store in Berlin.
It was then delivered by truck and precisely lowered into the hole prepared by our landscaping contractor.
It worked perfectly and took only 30 minutes.
They come with a 2.5-meter (8 feet) diameter and various depths. We have a submersible pump connected to it, which supplies three faucets on our property.
It works great.
For example, the one with a depth of 4.25 meters (14 feet) holds 15,000 liters (3,962 gallons). 😉

You will hardly be able to convert the soakaway shaft into a cistern with reasonable effort. You would need to completely empty the shaft (how do you get several cubic meters of gravel out through a small opening?) and waterproof the bottom and sides. It is more practical to install a proper cistern in between. Its overflow can then be directed to the soakaway shaft.