French drain
Gravel trench with a perforated pipe.
18 $/m average price in United States
About the material
A gravel-filled trench wrapped in geotextile with a perforated pipe at the bottom. Water seeps through the gravel into the pipe and drains away, while the gravel also stores and spreads flow.
Where it is used
Relieving wet spots and draining along foundations and paths.
