Is it permissible to bury bodies above ground due to groundwater flow, and is it permissible to transfer recently buried bodies to new graves, and is it permissible to build over the place of old graves?

The basic principle is that burying bodies above ground is not permissible because it is not considered a burial, unless water springs from the grave during excavation and no other option is available. In such a case, burial above ground is permissible due to the harm water would cause to the deceased. It is not permissible to move bodies after burial except for a legitimate reason, such as the grave being exposed to harm. It is also not permissible to build upon graves until the bodies have decomposed and turned into dust. At that point, it becomes permissible to utilize the cemetery.