Homeowner guide
Hillside drainage solutions for Bay Area yards
Short answer
Hillside drainage usually combines two things: catching surface water (swales, catch basins, channel drains) and carrying it in solid pipe to a safe outlet, plus handling water moving through the soil with French drains or drainage behind retaining walls. Which ones a yard needs depends on its slope, soil and where water collects, which Alfonso checks on site.
Start with where the water goes
Watch the yard during a rain: where water comes from uphill, where downspouts empty, and where it pools against the house, patio or walls. That tells you which problem to solve first.
Surface water: swales, catch basins and channel drains
A shallow swale or a row of catch basins intercepts water running down a slope before it reaches the house. Channel drains work across patios and driveways. The water then travels in solid pipe to an approved outlet.
Water in the soil: French drains
A French drain is a trench with perforated pipe in drain rock that collects water moving underground and carries it away. It helps soggy areas and uphill sides of a house.
Drainage behind retaining walls
Water trapped behind a wall builds pressure that can make it lean or crack. Drain rock and perforated pipe behind the wall let that water out. Restoring an older wall is a good time to add it, as on our Lafayette wall restoration.
Do it before the heavy rains
Erosion and water damage get worse with every storm. Alfonso can walk the property, look at the uphill side, existing drains and problem spots, and give you a free written estimate.