French drain · cost
French drain cost
A French drain runs roughly $10–$100 per linear foot outdoors, and more for an interior basement system with a sump. Estimate your run below, then see which type your water problem calls for.
Estimate only — the right fix depends on where the water comes from. Have a contractor diagnose the source first.
Cost by drain type
The wide exterior range reflects depth and access: a shallow yard drain in open ground is cheap; a deep drain alongside the foundation, around obstacles, is not. Interior systems cost more per foot because the basement slab has to be opened and re-poured.
Match the drain to the water
Water pooling in the yard or against the house? An exterior drain (and basic regrading and gutters) often solves it cheaply. Water seeping up through the basement floor or wall–floor joint? That’s hydrostatic pressure, and an interior drain-tile system with a sump is the usual fix. Putting in the wrong one is the most common — and most expensive — waterproofing mistake.
Frequently asked questions
How much does a French drain cost?
An exterior French drain typically runs about $10–$100 per linear foot installed, depending on depth, length, and access. An interior basement drain-tile system (which routes water to a sump pump) costs more per foot because it involves breaking and re-pouring the basement floor.
Interior vs. exterior French drain — what’s the difference?
An exterior French drain intercepts surface and groundwater out in the yard before it reaches the house. An interior drain (drain tile) sits inside the basement perimeter and collects water that has already reached the footing, sending it to a sump pump. Yard water problems favor exterior; chronic basement seepage usually needs interior drainage.
Is a French drain worth it?
If you have recurring water pooling against the foundation or a chronically damp basement, yes — managing that water is far cheaper than repairing the foundation damage it eventually causes. The key is matching the drain type to where the water actually comes from.
Does insurance cover a French drain?
No — drainage and waterproofing are preventive maintenance, which homeowners insurance excludes. You pay for it out of pocket. It is, however, one of the cheapest ways to prevent far more expensive foundation and water damage down the line.
Sources & methodology
- Waterproofing & repair cost data — HomeGuide
- Foundation repair cost data — Angi (national average ≈ $5,000; range ≈ $2,200–$8,100)
- Foundation & basement repair cost guides — This Old House
- A licensed structural engineer / foundation contractor in your area — the authoritative source for diagnosis, scope, and a stamped repair plan
Estimates compiled from the sources above and standard cost models — not engineering, professional, insurance, or legal advice, and may not reflect your policy or local prices. See our full methodology and disclaimer.