A French drain is a trench, backfilled with gravel or crushed stone around a perforated pipe (pipe side up), that collects and carries away excess surface or ground water.1 A filter fabric around the gravel is typically needed to keep soil from clogging the system over time.2 Despite their common use, French drains have a reputation for being unreliable as a permanent solution and are better suited to temporary or supplementary drainage than critical, long-term control.3