We recently bought a 100 year old historic home and have a cistern on the property. The cistern is about 10-12 feet in diameter is at least 12 or more feet deep and is completely built out of brick. (The bricks are staggered so that the inside of the cistern looks like the inside of a ball; it's round. Yes, the "roof" of the cistern is brick too.) It seems as if originally all of the gutters and downspouts were routed to the cistern to collect rain water from the roofs of the house and garage. It doesn't appear to have been connected to the house water but was to supply water for the greenhouse on the property.

Now for the questions...

The cistern is now under a driveway. We have been careful not to park on it for fear of weakening it and possibly causing it to fall in. However, I'm not sure we need to worry. Thoughts?

We also need to replace the driveway in the next 3-5 years or so and I'm wondering if jackhammering the driveway above the cistern will damage it.

Last, several of the clay pipes to the cistern have been crushed or are filled with debris. We plan on digging up and replacing the pipes where we can. However we anticipate the need to run new pipe from some of the other gutters. Is it safe to break through another opening for the new pipe from the other gutters? Or would this damage the structural integrity of the cistern?

If anyone has any experience with brick or similar cisterns and could share any insight, thoughts or experience I would greatly appreciate it. Thank you!