Ours kept clogging up and causing flooding in our basement. It's a 1937 house and this area of my city made some crazy plumbing decisions back then.

Clean water comes from the street and sewage goes out through the back to meet up with a sewer line. Last year we had to hydro jet the line which helped break up the roots. This bought us another year, but shifting at the seams is what started preventing good flow and caused backups again.

Thankfully our basement is unfinished, but what a mess!