Building a French Drain to Redirect Yard Water

A homeowner in Southern Maine has standing water in two backyard spots after heavy rain. The yard slopes slightly from neighboring properties and the driveway. A follow-up asks about running a French drain 75 feet with a slight turn, connecting multiple drains, and proper construction.

French Drain Design and Installation

• Pipe: Use 4" black corrugated perforated drain tile (standard). It’s flexible, inexpensive, and handles turns easily. PVC perforated pipe is stronger but harder to install.
• Slope: Minimum 1/4" per 10 feet. Eyeball the trench downhill, then test with a hose—adjust any low spots where water pools.
• Filter fabric: Wrap the pipe with landscape fabric (or buy pipe with a pre-wrapped sock) to keep soil from clogging the holes. Cover the top holes; bottom holes can clog without harm.
• Gravel: Use cheap “chat” (road base gravel). Fill around and over the pipe, then add soil and grass seed. Trench depth: 5" (4" pipe + 1" soil cover).
• Outlet: Run to a low area, a pop-up emitter, or a rock-filled sump hole (at least 5-gallon bucket size). Check local codes—some prohibit discharging onto sidewalks/streets due to ice risk.
• Multiple drains: Yes, several French drains can feed into one main trunk line.

Distance and Turns

75 feet with a slight turn is no problem—gravity works at any distance if slope is maintained. The corrugated pipe handles curves naturally.