How to Install a French Drain for Garden Beds (San Diego)

Move Water With Intent

Use French drains for soggy lawns, downspout discharge, and slope seepage when you have somewhere legal for water to exit. Keep continuous fall and fabric/gravel layering clean.

Build the Drain Step by Step

1. 1

   Map the low path

   Watch during a storm. Mark where water sits and where it can exit without flooding a neighbor or foundation.

2. 2

   Confirm a legal outlet

   Daylight to a safe landscape area, approved storm connection, or dry well per local rules. Do not aim at the property line.

3. 3

   Dig with continuous slope

   Maintain roughly 1–3% fall. Flat trenches puddle; reverse grade backflows.

4. 4

   Fabric, gravel, pipe, gravel

   Line with fabric, set pipe holes oriented per manufacturer guidance, surround with clean rock, wrap, and backfill.

5. 5

   Backfill and test

   Run a hose test before final landscaping. Keep surface inlets clear of mulch dams.

San Diego French Drain Tips

• This is site drainage infrastructure — different from the gravel-under-soil myth in raised beds.
• Combine with mulch and vegetation on slopes for erosion control.