French drains
A French drain gives water a faster path than the clay around it. Here's how they work and when they make sense in Clarksville yards.
A French drain is a trench lined with filter fabric, partly filled with washed gravel, with a perforated pipe in the bottom. Water soaks into the gravel faster than it can move through the surrounding soil, enters the pipe and flows downhill to an outlet. It's the usual fix when water isn't just running across the surface but saturating the ground.
When does a French drain make sense?
- A low part of the lawn that stays soft or squishy for days after rain
- A slope above the house that sends water toward the foundation
- Seepage along a retaining wall or at the bottom of a hill
- Wet spots that come back even after the surface has been regraded
Why does Clarksville clay matter?
Highland Rim subsoils are often clayey, and clay moves water slowly. A drain only works if the trench is deep enough to reach the wet layer, the fabric keeps fine clay out of the gravel, and the pipe has steady fall to a free outlet. A French drain that ends in a pit dug into the same clay will just fill up and sit.
Where does the water go?
That's the most important question to ask. Good outlets are a curb or street gutter where allowed, an existing ditch or drainage swale, or a pop-up emitter in a part of your own yard that drains well. In karst areas, don't let anyone simply aim the pipe at a sinkhole: Montgomery County says increasing runoff into a sinkhole needs a TDEC Underground Injection Control permit.
What should the quote say?
- Trench route, depth and length
- Pipe type and size, fabric and gravel
- Where the outlet is and how it's protected
- Who calls Tennessee 811 and how lawn and landscaping will be restored
The contractor prices the job after walking the yard and seeing where the water comes from and where it can go. We don't quote prices, and any number given over the phone before a site visit is only a rough starting point.
Where we connect you with help
Common questions
How long does a French drain last?
It depends on how well fine soil is kept out. Fabric, clean gravel and cleanouts help. Ask the contractor how the drain can be flushed later.
Is a French drain the same as a curtain drain?
Close. A curtain drain is a French drain placed across a slope to intercept water before it reaches the house or a wet area.
Related services
- Downspout drain lines
- Yard grading and swales
- Sump pumps and crawl space water
- Dry wells and channel drains
More background: Montgomery County drainage guide.
Standing water in the yard or a wet crawl space?
Call now and a local drainage contractor will help you figure out where the water is coming from.