French drains redirect subsurface water away from foundations, yards, and basements. They're one of the best DIY drainage solutions — materials are cheap and the installation is straightforward if you don't mind digging.
Quick answer: French drains cost $10–$30/linear foot for DIY materials and $25–$60/linear foot professionally installed. A 50ft exterior drain runs $160–$300 DIY or $1,250–$3,000 installed. Interior basement drains cost 2× more.
| Drain Length | DIY Materials | Professionally Installed |
|---|---|---|
| 25 ft | $80–$150 | $625–$1,500 |
| 50 ft | $160–$300 | $1,250–$3,000 |
| 75 ft | $240–$450 | $1,875–$4,500 |
| 100 ft | $320–$600 | $2,500–$6,000 |
| Material | Cost |
|---|---|
| Gravel (washed 3/4") | $100–$180 |
| Perforated pipe (4" PVC or corrugated) | $25–$50 |
| Landscape fabric | $15–$30 |
| Fittings and connectors | $20–$40 |
| Drain sock (optional) | $15–$25 |
| DIY Total (50 ft) | $160–$300 |
| Factor | Exterior | Interior (Basement) |
|---|---|---|
| Cost per linear foot | $25–$50 | $40–$100 |
| What it solves | Yard drainage, foundation water diversion | Basement waterproofing, water table issues |
| DIY feasible? | Yes — digging is the hard part | No — requires breaking concrete, sump pit |
| Disruption | Yard torn up, landscaping damage | Concrete floor removed and repoured |
| Additional costs | Landscaping repair ($200–$500) | Sump pump ($300–$600), concrete repair ($500–$1,000) |
| Best for | Surface water, soggy yards, downspout drainage | Basement water intrusion, high water table |
| Factor | DIY | Professional |
|---|---|---|
| Cost (50 ft exterior) | $160–$300 | $1,250–$3,000 |
| Time | 1–2 days (full day of digging) | Half day with equipment |
| Skill level | Beginner to intermediate — slope is critical | N/A |
| Tools needed | Shovel (or rent trencher $150–$250/day), level, wheelbarrow | Included |
| Quality risk | Incorrect slope = water doesn't flow | Guaranteed proper slope and drainage |
| Best for | Exterior yard drains on flat/gentle slopes | Interior drains, complex routing, steep slopes |
Drain length — longer drains cost more in materials and labor, but the per-foot cost decreases slightly for longer runs due to setup efficiency.
Trench depth — deeper trenches (2ft+ for foundation drainage) require more excavation and gravel. Standard yard drains are 12–18 inches deep.
Soil type — clay soil is harder to dig and drains poorly, requiring more gravel. Sandy soil is easy to dig but may not need a french drain at all.
Interior vs exterior — interior basement drains cost $40–$100/lf because they involve breaking up and repouring concrete floor, plus a sump pump installation.
Discharge point — draining to daylight (pipe exits on a slope) is cheapest. A dry well ($500–$1,500) is needed if you can't outlet to a slope. Connecting to storm drain may require a permit.
Obstacles — tree roots, utilities, and rocky soil increase excavation difficulty and cost.
Calculate your exact french drain materials with our French Drain Calculator.
A 50ft exterior french drain costs $160–$300 in DIY materials (gravel, pipe, fabric, fittings). Professionally installed, expect $1,250–$3,000. Interior french drains (basement waterproofing) cost $2,000–$5,000 for the same length.
Yes — exterior french drains are a solid DIY project. The hardest part is digging the trench (1–2ft deep, 6–12in wide). A 50ft trench takes a full day by hand. Rent a trencher ($150–$250/day) to cut that to 2–3 hours. The actual drain installation is straightforward.
Most exterior french drains don't need a permit unless you're connecting to a storm drain system. Interior french drains (basement) may require a plumbing permit. Check with your local building department.
A properly installed french drain with landscape fabric to prevent soil intrusion lasts 20–30 years. Without fabric, sediment clogs the gravel in 5–10 years. PVC pipe lasts indefinitely; corrugated pipe may need replacing after 15–20 years.
French drains handle subsurface water (groundwater seeping through soil). Catch basins collect surface water (rain pooling in low spots). Channel drains handle concentrated surface flow (bottom of a driveway). Many yards need a combination.