If water pools in your yard after every rain, you don't have a landscaping problem. You have a drainage problem. And in North Texas, where the soil is heavy clay that doesn't absorb water well, drainage issues are everywhere.
What a French Drain Actually Is
It's a trench (usually 12 to 18 inches deep and 6 to 12 inches wide) filled with gravel and a perforated pipe. Water enters the gravel, flows into the pipe through the perforations, and the pipe carries it away to a discharge point. That's it. Simple concept, but it works.
The "French" part has nothing to do with France. It's named after Henry French, a Massachusetts farmer who wrote about the technique in 1859.
Do You Need One?
Signs your DFW yard needs a French drain: standing water in the yard 24+ hours after rain, water pooling against your foundation, soggy spots that never seem to dry, water flowing toward your house instead of away from it, or a slab foundation that's showing signs of movement.
That last one is a big deal in Dallas. Our clay soil expands when wet and contracts when dry. If water consistently pools against one side of your foundation, that side swells while the other side shrinks. Over time, that causes cracks and settling. A $1,500 French drain can prevent a $15,000 foundation repair.
How We Install Them
We dig the trench with a slight slope. You need at least 1% grade (1 inch of drop per 8 feet of run) for gravity to move the water. In flat yards, we sometimes trench deeper at the discharge end to create the slope.
Landscape fabric lines the trench to keep clay soil from clogging the gravel. Then we lay 2 to 3 inches of gravel, set the perforated pipe (4-inch corrugated or PVC), and fill the rest with gravel. The top gets covered with soil and sod, or left exposed with decorative gravel.
The discharge point matters. We either daylight the pipe at a lower elevation in the yard, connect to a storm drain, or run it to the curb. Dallas code has specific rules about where you can discharge drainage water, so check before you dig.
Cost in DFW
$25 to $50 per linear foot is the typical range. A simple 30-foot run: $750 to $1,500. A full perimeter system around part of the house: $3,000 to $6,000. The big variable is how much digging is involved and where the water needs to go.
Clay soil tip: If your yard is pure DFW clay (and it probably is), consider adding a catch basin at the low point of your yard in addition to the French drain. A catch basin is a surface-level grate that collects standing water directly. The French drain handles subsurface water. Together they solve most drainage problems.
Can You DIY It?
Technically yes. Rent a trencher from Home Depot for about $200/day, buy the pipe and gravel, and dig. But DFW clay is brutal to trench through. It's dense, sticky, and heavy. What looks like a weekend project often turns into three weekends and a sore back. The other risk: getting the slope wrong. If the pipe doesn't slope consistently, water sits in the pipe and you've built an expensive underground puddle.