French Drain Cost Per Foot: 2026 Pricing Guide for Homeowners
Most homeowners pay between $25 and $50 per linear foot to have an exterior french drain installed, with material-only costs running closer to $10 to $25 per foot. The average french drain cost per foot lands around $35 installed for a typical shallow yard trench, though basement and interior systems routinely push past $60 a foot once you add a sump pump, wall sheathing, and concrete work. Total projects range from about $1,000 for a 50-foot DIY trench to $10,000-plus for a full perimeter basement system.
That spread exists because a french drain is never just a pipe in the ground. Gravel, landscape fabric, trench depth, access, soil type, and whether you handle the work yourself all move the per-foot price in either direction. This guide breaks the number down line by line so you can estimate your own project with confidence and know exactly what a contractor’s quote should include.
What Is a French Drain and Why It Costs What It Does
A french drain is a gravel-filled trench holding a perforated pipe that captures groundwater and carries it away from your foundation, yard, or retaining wall. Water seeps into the trench, filters through the stone, enters the pipe through its perforations, and flows by gravity to a safe discharge point — a storm drain, a dry well, or a downhill slope.
The per-foot cost reflects more than the pipe. A properly built french drain layers four materials in a specific order:
- Perforated pipe (usually 4-inch corrugated PVC or rigid PVC)
- Washed gravel or crushed stone (the “reservoir” that lets water in)
- Landscape fabric (keeps silt from clogging the pipe over time)
- Backfill and topsoil (to restore the surface)
Skip the fabric or use the wrong stone, and the drain silts up within a few seasons — which is exactly the kind of hidden failure that turns a cheap quote into an expensive re-excavation.
French Drain Cost Per Foot: Breaking Down the Numbers
Here’s where the rubber meets the trench. The exact french drain cost per foot depends on whether you’re counting materials only or a full installed system, and whether the trench sits outside in the yard or inside along a basement wall.
Material-Only Costs
If you rent a trencher and do the digging yourself, your per-foot budget is mostly pipe, stone, and fabric:
| Item | Cost per foot (approx.) | Notes |
|---|---|---|
| 4-inch corrugated perforated pipe | $0.50–$1.00 | HDPE or PVC, with sock |
| Washed gravel (1.5-inch) | $4–$9 | Depth-dependent; 2 ft deep needs more stone |
| Landscape fabric | $0.50–$1.50 | Non-woven geotextile, not weed barrier |
| Fittings, couplings, pop-up emitter | $1–$3 | Averaged across the run |
Realistically, a DIY exterior french drain runs $10 to $25 per linear foot in materials, plus a half-day trencher rental of $100 to $200 (or the cost of a shovel and a weekend).
Installed (Labor Included) Costs
Hiring a drainage contractor or landscaper adds excavation labor, disposal, and markup:
- Shallow exterior yard drain (12–24 in. deep): $25–$50 per foot
- Deep foundation drain (3–6 ft. deep): $50–$90 per foot
- Interior basement drain with sump pump: $45–$100 per foot
- Under-slab or crawl space work: $60–$150 per foot
Depth is the single biggest labor driver. Digging a two-foot trench by hand is slow; digging a six-foot foundation trench requires shoring, wider access, and more removed soil — all billed by the hour.
Photo by Wayee Tan via Pexels
Exterior vs. Interior French Drains
Not all french drains do the same job, and the two main types differ sharply in price.
Exterior french drains run around the outside of the foundation or through a soggy yard. They intercept water before it reaches the house and are the cheaper option per foot because the trench is open and accessible. Expect $25 to $50 per foot installed for yard work and $50 to $90 per foot for deeper foundation waterproofing.
Interior french drains run along the inside of a basement wall, beneath the slab edge, channeling seepage into a sump basin. They’re common where exterior digging is impossible — tight lots, walkways, or neighboring structures. They cost more per foot ($45 to $100) because they involve breaking concrete, and they almost always require a sump pump, adding $600 to $1,800 to the total. Many contractors recommend an interior drain when you’re already finishing a basement or installing a new retaining wall, since the excavation is easiest during other work.
What Drives Your Per-Foot Price Up or Down
Beyond the exterior/interior split, six factors routinely shift a french drain quote by thousands:
- Trench depth and soil type. Rocky or clay soil is slow to dig; sand is fast. Deep trenches cost more.
- Access. A backyard with no machine access forces hand digging, which doubles labor.
- Discharge distance and slope. A long, flat run needs a deeper trench and sometimes a catch basin or pop-up emitter.
- Permits and code. Some municipalities require permits for drain discharge into storm systems.
- Landscaping restoration. Re-sodding or re-seeding after backfill adds $1–$3 per square foot.
- Regional labor rates. Coastal metro areas bill $75–$120 per hour; rural areas often $45–$65.
Ask any contractor to itemize these six line items. A quote that lumps everything into one number hides exactly where the money is going.
DIY vs. Hiring a Pro
A short, shallow yard french drain is one of the more approachable exterior DIY projects. A deep foundation drain is not.
| Feature | DIY Exterior Drain | Pro Installed System |
|---|---|---|
| Material cost per foot | $10–$25 | $25–$90 |
| Total for 50 ft. | $500–$1,300 (plus trencher) | $1,500–$4,500 |
| Equipment needed | Trenching shovel or rented trencher | Excavator, laser level, dump trailer |
| Risk of error | High — slope, fabric, clogs | Low — licensed and warrantied |
| Best for | Yard drainage, shallow slope | Foundation waterproofing, basements |
The most common DIY mistake is an inadequate slope. A french drain needs about 1 inch of fall per 8 feet of pipe to move water reliably. Too little fall and the pipe sits full of stagnant water; too much and the water outruns the soil’s ability to shed it. Get the slope wrong and you’ll be re-digging your own trench in two years — which is when most DIYers call the pro they should have hired first.
Photo by David McElwee via Pexels
How to Keep Your French Drain Cost Per Foot Honest
Getting a fair price is mostly about getting a complete, comparable quote. Before you sign:
- Get three itemized bids that break out excavation, materials, disposal, and restoration.
- Specify the pipe. Rigid PVC costs more but resists crushing; corrugated with a filter sock is fine for shallow yard runs.
- Verify the discharge point. A drain that dumps water into your neighbor’s yard or the street may be illegal — confirm the plan ends at a legal outlet.
- Bundle the work. Installing a french drain at the same time as a yard drainage project or a new retaining wall saves on mobilization and equipment fees.
The cheapest quote is rarely the best french drain. A $20-per-foot trench with no fabric and no proper slope will cost more per foot over its life than a $45-per-foot system that lasts 20 years.
Frequently Asked Questions
How much does a french drain cost per foot installed?
Plan on $25 to $50 per linear foot for a shallow exterior drain and $50 to $90 per foot for a deep foundation drain, including labor. Interior basement systems run $45 to $100 per foot.
Is a french drain worth the cost?
Yes, when water is actively threatening a foundation, flooding a basement, or pooling in a yard. A $2,000–$6,000 drain that prevents $15,000–$40,000 in foundation repair is one of the better returns in home maintenance.
How long does a french drain last?
A properly installed drain with washed stone and geotextile fabric typically lasts 20 to 40 years. The pipe itself can outlive that; failure usually comes from silt clogging the fabric or crushed pipe, not from the pipe rotting.
Can I install a french drain myself?
A shallow yard french drain is a reasonable DIY project if you can dig a trenched, sloped channel and are willing to haul gravel. Foundation and basement drains are better left to licensed waterproofing contractors because of the depth, access, and structural risk involved.
Does a french drain need a permit?
It depends on your municipality and where the water discharges. Drains tied into a storm sewer or crossing a property line often need a permit. Check with your local building department before digging, and call 811 to mark underground utilities first.
The Bottom Line
A french drain is one of the few home projects where a few dollars per foot makes the difference between a 30-year fix and a two-year disappointment. Expect the french drain cost per foot to run $25 to $50 installed for exterior yard work and $45 to $100 for interior or deep foundation systems, with materials alone at $10 to $25 if you dig it yourself. Match the drain type to the problem — exterior for groundwater and yard flooding, interior for seepage you can’t reach from outside — and get three itemized bids that specify the pipe, the stone, the fabric, and a legal discharge point.
For more on what adjacent drainage and wall work should cost, see our guides to retaining wall costs per linear foot and yard drainage pricing. According to the home-improvement experts at This Old House, a properly installed french drain is one of the most effective ways to keep groundwater away from a foundation, and Bob Vila similarly ranks drainage correction among the highest-value basement fixes. Get your quotes, check the slope, and you’ll pay once instead of twice.
