However, French drains can be surprisingly expensive to install, and if you're new ... and says 'Parts you will need are a perforated pipe, gravel, fabric, and catch basins, which are optional.
A French drain is a narrow trench set back from, but parallel to, the top of the bluff and filled with free-draining sand or gravel. A perforated, corrugated plastic pipe at the bottom collects water ...