My yard seems to be collapsing in the back in a ring pattern around a smallish circular mound. What is going on? One hole, while not very wide is more than three feet deep. Is this my cesspool collapsing or is it something else? Otherwise we seem to have no sewer problems at all; no weird gurgling, no slow draining, nothing backing up.
Sounds like your sewer might be leaking and causing a washout. If there is water in the hole take some color egg dye and flush down toilet and see if it comes in hole are have a camera run through the sewer.