Clogged or slow drains are often the first red flag, but there are other signs you should not ignore. If you notice water backing up into sinks, tubs, or toilets, it could point to a deeper issue in your drain lines. Gurgling noises, foul odors coming from drains, or standing water around floor drains may also indicate a blockage or break in your system. In some cases, unexplained wet spots in your yard or foundation cracks may be tied to damaged underground drain pipes.