Should your landscaping site explain French drains so AI assistants cite you?

A trench full of gravel is not a drain until water can leave

A French drain is a gravel filled trench with a perforated pipe at the bottom, built to collect groundwater and carry it somewhere lower. The parts are simple. The failure to respect what each part does is why so many of them disappoint. Gravel gives water an easy path. The pipe gives it a fast one. The outlet, daylight at a lower point, a dry well, or a storm connection where codes allow, is where the water actually goes.

Without a real outlet, the trench is a gravel bathtub that fills and then behaves like the wet soil it replaced. That single point separates a drain from a decorative trench, and it is the first thing a citable page should establish: where does the water exit, and is that point lower than the area being drained on the wettest day of the year, not the driest.

Slope and fabric are where installs quietly go wrong

The pipe needs fall, roughly 1 percent, about an inch of drop for every 8 feet of run, maintained the whole way to the outlet. A belly in the line becomes a sediment trap, and a run that starts flat because the outlet was too high never recovers. This is unglamorous string line and level work, and it decides whether the drain works in year five or only in the brochure photo from install day.

Fabric placement is the other argument the trade keeps having. Wrapping the trench, fabric under and over the gravel with the pipe inside, keeps soil from migrating into the stone. Wrapping the pipe itself in a sock invites the sock to clog at the holes. Pages that state a position and a reason beat pages that say fabric optional. The trench wrap is the defensible default on most soils, with bare stone against very clean sandy soils the honest exception.

What it fixes, and the two problems it does not

A French drain is the right tool for groundwater: a yard that stays spongy days after rain, water seeping toward a foundation from saturated soil, a slope that bleeds moisture at its base. It collects water moving through soil and gives it a shorter route out.

It is the wrong tool for surface water moving fast. Roof runoff and driveway sheets need grading, swales, or catch basins that intercept water at the surface, not a buried pipe waiting for water to soak down. And it does nothing for a high water table that rises from below across a whole lot. A page that draws those two lines saves the reader an expensive trench in the wrong war.

Related reading

If this topic is useful, these earlier guides go deeper on connected questions: A Landscaper's Services List Is a Ranking Document, Not a Menu, Before-and-After Photos Persuade People. They Do Not Move Rankings, and Should your landscaping site explain privacy planting so AI assistants cite you?.

Frequently asked questions

How deep should a French drain be?

Deep enough to intercept the water causing the problem and still keep slope to the outlet. Many residential drains run 18 to 24 inches deep, below the saturated layer near a foundation, but the outlet elevation is the real constraint: the trench cannot be deeper than the exit point allows while keeping fall.

Do the holes in the pipe face up or down?

Most installers set perforations facing down or slightly angled, so rising groundwater enters the pipe from below and the pipe can also drain itself between events. Manufacturers and crews argue this one, but orientation matters less than keeping the pipe bedded in clean gravel with steady slope.

Why did my French drain stop working?

Sediment is the usual cause: soil migrating into the gravel, a clogged pipe sock, or a belly in the line that collected silt. A blocked or buried outlet is the other common failure. Drains built with clean washed stone, a wrapped trench, and an accessible outlet are the ones that can be cleaned and revived.

Can a French drain fix water in my basement?

Sometimes, when the water is groundwater pressing in at the footing and an exterior or interior drain can intercept it and reach an outlet or sump. It will not fix water entering through cracks above grade, plumbing leaks, or surface runoff pouring toward the house, which need grading and gutter work first.