Walnut Creek · Lafayette · Orinda · Danville
Yard Drainage and French Drains in Walnut Creek, CA
Standing water, hillside runoff or a French drain that stopped working? See your options and costs, then request a quote from a local drainage contractor.
Most yard drainage problems here come down to three fixes:
Start with the symptom
What's happening in your yard?
Pick the closest match. Each page explains the likely cause, the usual fix, and what it involves.
- Puddles that sit for daysLow spots, compacted or heavy soil, no outlet
- Water against the houseDownspouts and grade sending water to the foundation
- Runoff coming down the hillUphill water, erosion, a wet strip at the toe of the slope
- A French drain that quitSilted rock, crushed pipe, roots or a buried outlet
- Ready for a French drainLayouts, outlets, trees and permits
- Not sure what's wrongMatch the symptom to the fix before anyone digs
Hillside lots
On a hill, water arrives from above as well as from the sky
Lamorinda and the Walnut Creek and Danville foothills put many homes below a slope. In long storms, rain soaks the hillside and shallow groundwater moves downhill until it surfaces at a patio, a retaining wall or the back of the house.
The U.S. Geological Survey found that most damaging landslides in Contra Costa County from 1950 to 1971 occurred on ancient landslide deposits and followed long storms (USGS Bulletin 1388). Drainage can't stabilize a moving hillside, but keeping water out of the soil is part of every good hillside plan.
The workhorse fix
How a French drain works
A French drain is a trench filled with washed rock around a perforated pipe, usually wrapped in filter fabric. Water in the surrounding soil moves into the rock, enters the pipe and flows downhill to an outlet: a curb or storm connection where allowed, a dry well, or a spot where it can daylight safely.
It solves soggy soil and seepage. It does not fix a yard that is graded toward the house or a downspout dumping on the foundation; those need surface fixes first.
Budget
What drainage work costs here
$35–$90+ per linear foot
That is the Bay Area range one local contractor publishes for French drains, with most projects between $3,500 and $13,500+ (Cardona Construction, 2026). Depth, slope access, hand digging, concrete and landscape restoration move the number most. Real quotes can land below or above.
See the full cost guide- Tell us what's happeningCall or send the short form. Where the water sits, when it shows up, whether you're on a slope.
- A local drainage pro follows upThey ask a few questions and set a time to walk the yard, ideally when you can point to where water collects.
- Get a written quoteCompare it against our quote checklist: linear feet, depth, outlet, restoration, permits.
Where we help
Walnut Creek and the hills around it
Walnut Creek, Lafayette, Orinda, Moraga, Danville, Alamo, Blackhawk, Diablo, Pleasant Hill, Concord and Clayton.
Walnut Creek specifics
- Walnut Creek runs its own building department; check permit needs through the city permit portal before grading or connecting to the street.
- Native oaks are highly protected, and trees 28 inches or more in circumference need a permit to remove (tree ordinance). French drain routes near oaks should be planned around the roots.
- Walnut, Tice and Grayson creeks run through town. The city notes a 26% chance of flooding over a 30-year mortgage for homes in the 100-year flood zone (city flood protection). Yard drainage handles rain on your lot, not creek flooding.
Check any contractor before work starts
In California, work over $1,000 in labor and materials requires a CSLB license (AB 2622). Look up the license number on the CSLB website, confirm it's active, and confirm workers' comp if the contractor has employees.
Quote checklist & red flagsQuestions homeowners ask
Who do I call for yard drainage?
For water problems in the yard itself (puddles, soggy lawn, water against the house, hillside runoff), call a drainage contractor. Many are licensed landscape (C-27) or earthwork (C-12) contractors. If the ground is cracking or walls are tilting, talk to a geotechnical engineer first. See how to choose a drainage contractor.
How much does a yard drainage system cost?
Bay Area French drains commonly run about $35–$90+ per linear foot, and most local projects land between $3,500 and $13,500+ (Cardona Construction, 2026). A single downspout line or catch basin costs far less; deep hillside drains cost more. Real quotes can come in below or above these ranges. Details: French drain and yard drainage cost.
What are the best drainage options for my backyard?
It depends on where the water comes from. Roof water needs downspout lines and an outlet. Low spots that hold rain need regrading or a catch basin. Soil that stays soggy for days needs a subsurface (French) drain. Water coming down a hill needs an interceptor drain across the slope. The standing water guide matches symptoms to fixes.
How do I fix a waterlogged backyard?
Start by finding the source: watch the yard during a storm, check where each downspout empties, and look for low spots and uphill runoff. Then fix the cause: redirect roof water, reshape the grade, or install a French drain with a proper outlet. Aerating or adding topsoil alone rarely holds up through a wet winter.
When is the best time to install a French drain here?
Before the rain. Concord's long-term normals show about 3.2 inches of rain in each of December, January and February and essentially none in July (NOAA normals). Dry-season trenching is cleaner, and you can test the system on the first storms.
Next step
Get water out of the wrong places before the next storm
Call to describe what's happening, or send the short form and a local drainage pro will follow up to schedule a look and a written quote.
Call (925) 489-1563