French drains
On flat coastal lots, a French drain lives or dies by its outlet. Here's how they work in Savannah and when they're the right call.
A French drain is a trench lined with filter fabric, filled with washed stone and fitted with a perforated pipe near the bottom. Water in saturated soil moves into the stone more easily than it moves through the ground, drops into the pipe and runs to an outlet. It's the right tool when the ground itself is staying wet, not just when water sheets across the surface.
When does a French drain make sense here?
- A low part of the lawn that's still squishy two days after a storm
- A narrow side yard between houses where water collects along the fence
- Seepage at the edge of a slab, patio or paver walkway
- Wet ground at the bottom of a raised bed, berm or retaining edge
Why is Savannah different?
Two things: very little fall and high ground water. Much of Chatham County sits within about 20 feet of sea level, so a long pipe may only have a few inches of drop to work with. And in low areas the water table can rise close to the surface in the wet months. A trench that goes deeper than the outlet just becomes a buried pond. Contractors here often keep drains shallower, use the gentlest slope that still flows, and spend more time finding a lower discharge point than digging a deeper trench.
Where will the water go?
Ask this first. Common outlets are the street gutter where the city allows it, an existing roadside ditch or swale, or a pop-up emitter at a lower part of your own yard. Don't let anyone route a drain straight onto a neighbor's lot. If your property borders salt marsh, ask how the outlet relates to Georgia's 25-foot marsh buffer before any digging starts.
What should the quote spell out?
- Trench route, length and depth, and the fall from start to outlet
- Pipe type and diameter, fabric and stone
- The outlet location and how it's protected from clogging
- Who submits the Georgia 811 request and how sod and beds are restored
Pricing comes from the contractor after a site visit, once they've seen how the lot sits, how high the ground water is and where the water can be sent. We don't quote prices, and any figure given over the phone before someone walks the yard is only a rough guess.
Where we connect you with help
Common questions
Will a French drain lower the water table in my yard?
Only near the trench, and only if the outlet is lower than the wet ground. It can't drain water below the level of wherever it discharges.
Do French drains clog in sandy soil?
Fine sand and silt can work into the stone over time. Filter fabric and a cleanout port make it easier to keep the drain flowing.
Related services
- Downspout drain lines
- Yard grading and swales
- Sump pumps and crawl space water
- Catch basins and channel drains
More background: Chatham County drainage guide.
Yard still underwater a day after the storm?
Call now and a local drainage contractor will help you work out where the water should go.