French Drain Cost
A French drain costs $10–$30 per foot in the yard, $30–$90 for deep exterior perimeter runs, and $4,000–$17,000 for an interior basement system. Price your water problem by type and length.
French drain pricing follows where the water problem lives — a soggy lawn, a wet foundation, and a leaking basement call for different drains at very different depths — and how many feet the drain runs. The third question is gravity's: whether the water has a downhill escape, or needs a pump to make one.
Where's the water problem?
A soggy yard gets a surface or curtain drain. Water pooling against the house gets an exterior perimeter drain dug to the footings. Water already inside gets an interior system — along the basement perimeter or through the crawl space.
How long is the run?
Pace off the path the drain will take. Yard drains run from the wet spot to the discharge point; perimeter systems follow the foundation — a typical basement perimeter is 100–200 feet, and exterior drains price per side of the house (about 30–50 feet each).
Does it need a sump pump?
Drains want gravity — a downhill path to daylight or a storm drain. When the yard can't provide one, the water collects in a sump basin and a pump ejects it. Basement systems already include their pump.
Cost of 50 ft of a surface yard drain
$500–$1,500
excavation, gravel, perforated pipe, fabric, and backfill
Match the drain to the water — not the price
The types aren't interchangeable: a surface drain dries a lawn, a curtain drain intercepts water flowing downhill toward the house, an exterior perimeter drain keeps water off the foundation walls, and an interior system manages water that's already getting in. Fixing a basement problem with a yard drain saves money on the wrong solution — the water grades your work, not the invoice.
The rules that make a drain actually work
Gravity is non-negotiable: the drain needs at least a 1% slope — one foot of drop per 100 feet — and somewhere legal to discharge (daylight, a storm drain, or the sump). Exterior drains sit 12–24 inches deep and 2–5 feet off the foundation. And they're low-maintenance, not no-maintenance: roots and silt clog neglected lines, and clearing one runs $80–$500.
Per-foot rates by type: surface yard $10–$30, curtain $10–$35, exterior perimeter $30–$90 (priced per side of the house — a full wrap is all four sides of footage), crawl space $20–$40, interior basement $40–$85 with sump pumps included. Basement retrofits jackhammer the slab perimeter to reach the footings, which is most of their premium. Context for the escalation path: full basement waterproofing runs $6,000–$18,000, and unresolved foundation water can end in $23,000–$48,000 rebuilds.
💡About this calculator▼
A French drain is the rare home upgrade that's older than the country and still the right answer: a gravel-filled trench with a perforated pipe that gives water somewhere better to go than your lawn, your foundation, or your basement. The price spans a huge range — $500 yard fixes to $17,000 basement systems — because "French drain" names five different jobs at five different depths.
The ladder, shallow to deep: a surface yard drain ($10–$30 per foot) dries a soggy lawn. A curtain drain ($10–$35) intercepts water flowing downhill before it reaches the house. An exterior perimeter drain — weeping tile, dug down to the foundation footings — runs $30–$90 per foot and keeps water off the walls. Inside, a crawl-space drain runs $20–$40 per foot, and the big one — the interior basement perimeter system at $40–$85 per foot ($4,000–$17,000 typical) — jackhammers the slab edge to collect water at the footings and route it to a sump pump, included in the price.
The physics is the other half of the estimate: drains need gravity — a 1% slope and a discharge point — and where the yard can't provide one, a sump pump ($600–$2,500) makes the exit.
Pick your water problem below, pace off the run, and you'll have the range — plus the honest guidance on which drain actually fixes which problem, because the wrong one at the right price still leaves you wet.
Where the water is decides the drain; the drain and the footage decide the price.
The outdoor types. A surface-level yard drain ($10–$30 per foot) sits shallow and dries lawns and low spots. A curtain drain ($10–$35) runs across a slope uphill of the house, catching water on its way down. An exterior perimeter drain ($30–$90) is the serious version: excavated 12–24 inches or more down along the foundation — priced per side of the house, typically $1,200–$4,500 each — to relieve the water pressing on your walls.
The indoor types. When water is already coming in, interior systems collect it where it enters: a crawl-space drain runs $20–$40 per foot ($2,000–$8,000 typical), and a basement perimeter system runs $40–$85 per foot — the crew breaks the slab edge, trenches to the footings, lays pipe and gravel, and routes everything to a sump basin whose pump is part of the system and the price. Published basement totals: $4,000–$8,500 at 100 feet, $8,000–$17,000 at 200.
The gravity question. Every drain discharges somewhere: to daylight downslope, a storm drain, or a dry well. Outdoor drains without a downhill escape add a sump pump at $600–$2,500. The build itself is consistent across types — trench, fabric, gravel, perforated pipe, backfill — with depth doing most of the pricing.
📐How it's calculated▼
Total = run length × your drain type's per-foot rate, plus a sump pump where gravity falls short.
Per-foot rates: surface yard drain $10–$30 · curtain drain $10–$35 · exterior perimeter (weeping tile) $30–$90 · crawl space $20–$40 · interior basement perimeter $40–$85, sump pumps included.
Sump pump, when added to an outdoor or crawl drain: +$600–$2,500.
The published typical totals these produce: yard drains $500–$5,300 · curtain drains $1,500–$8,800 · exterior perimeter $1,200–$4,500 per side of the house · crawl spaces $2,000–$8,000 · basement systems $4,000–$17,000 — with the basement by-length pricing being exactly the arithmetic: 100 feet with one pump at $4,000–$8,500, 200 feet with two pumps at $8,000–$17,000.
The engineering constants: 12–24 inches deep, at least 12 inches wide, 2–5 feet off the foundation for exterior runs, and a minimum 1% slope — one foot of fall per hundred feet of drain.
🔍Finding your inputs▼
Where's the water problem? Follow the water, not the price list. Standing water or mush in the lawn: surface drain. Water arriving from a slope above the house: curtain drain, placed uphill to intercept. Damp foundation walls or water pooling against the house: exterior perimeter. Musty, wet crawl space: crawl drain (and consider encapsulation while the crew's under there). Water on the basement floor: the interior perimeter system — no shallower option fixes that one.
How long is the run? Pace it. Yard and curtain drains run from the problem area to the discharge point. Perimeter systems follow the foundation: exterior drains price per side (30–50 feet each, typically), and a full basement perimeter runs 100–200 feet for most homes. When in doubt, measure generously — drains that stop short of the discharge point are the classic DIY failure.
Does it need a sump pump? Walk the discharge path: if the drain can end somewhere lower than it starts — daylight on a slope, a storm drain, a dry well downhill — gravity works free. Flat lots and basements usually can't, so the water collects in a sump basin and a pump ejects it. Basement systems include the pump; for everything else it's the $600–$2,500 question this input answers.
⚠️Special situations▼
My basement leaks — interior drain or exterior excavation?
The honest trade: exterior perimeter drains fix the cause (water never reaches the wall) but require excavating the foundation — costly and landscape-destroying on a finished home. Interior systems manage the symptom brilliantly for less by collecting water at the footing and pumping it out, which is why retrofits usually go interior. Exterior wins during new construction or when the walls themselves need waterproofing repair. Many wet-basement fixes pair an interior drain with grading and gutter fixes outside — cheap prevention plus reliable collection.
Can I DIY a yard French drain?
The shallow yard drain is genuinely DIY-able: rent a trencher, mind the 1% slope (a string level is your friend), wrap the pipe and gravel in filter fabric, and call 811 before digging — buried utilities don't forgive. What separates working DIY drains from decorative trenches: an actual discharge point, fabric to keep silt out, and enough depth. Leave the exterior perimeter (foundation-depth excavation) and anything interior to crews — those are structural-adjacent digs.
Water comes at my house from a neighbor's slope
That's the curtain drain's exact job: placed across the slope uphill of your house, it intercepts subsurface flow before it arrives, at $10–$35 per foot. Two notes: position matters more than length (it must cross the water's actual path — a soil probe after rain finds it), and discharge law matters — most jurisdictions bar you from aiming collected water at the next property. Route to a storm drain, dry well, or your own downslope daylight.
The quote includes a sump pump I didn't ask about
Usually legitimate: flat lots and interior systems have no downhill escape, so the $600–$2,500 sump is how the water leaves. What to verify instead of fighting it: basin placement, where the discharge line runs (10+ feet from the foundation, not onto the neighbor), and — for basements guarding real value — a battery backup, because sump pumps fail exactly when storms knock power out. Our sump pump page prices replacements and backups.
How long does a French drain last — and why do they fail?
Decades when built right; the failure modes are all buildable-out: silt intrusion (missing filter fabric), root invasion (drains near thirsty trees), and crushed or shifted pipe (cheap pipe, sloppy backfill). Clearing a clogged line runs $80–$500 — worth doing at the first sign of the old symptoms returning, because a clogged drain quietly resigns while the water goes back to its old habits. Ask bidders what fabric and pipe they use; it's the longevity question in disguise.
❓Common questions▼
How much does a French drain cost?
Between $500 and $17,000, with the type doing most of the deciding: surface yard drains run $10–$30 per linear foot ($500–$5,300 typical), curtain drains $10–$35, deep exterior perimeter drains $30–$90 per foot ($1,200–$4,500 per side of the house), crawl-space systems $20–$40, and interior basement perimeter systems $40–$85 per foot — $4,000–$17,000 installed, sump pumps included.
How much does an interior basement French drain cost?
Figure $40–$85 per linear foot installed: $4,000–$8,500 for a 100-foot perimeter with one sump pump, up to $8,000–$17,000 for 200 feet with two. The price reflects the work — breaking the slab edge, trenching to the foundation footings, laying the collection system, and re-pouring — plus the sump system it all drains to. It's cheaper when installed during new construction, and it's the standard retrofit fix for chronic basement water.
Do French drains really work?
When matched to the problem and built to spec, very well — the design has drained fields and foundations for centuries. The three build rules that decide success: at least a 1% slope (one foot of fall per hundred feet), a real discharge point (daylight, storm drain, dry well, or sump), and filter fabric around the gravel so silt doesn't clog the pipe. Most 'French drains don't work' stories trace to a missing slope, a missing outlet, or a missing fabric wrap.
How deep should a French drain be?
Yard and curtain drains run 12–24 inches deep and at least 12 inches wide, placed 2–5 feet from the foundation when near the house. Exterior perimeter drains go much deeper — down to the foundation footings — which is why their $30–$90 per foot triples the yard rate. Depth follows the water you're intercepting: surface water needs shallow trenches; water pressing on basement walls needs the drain at the wall's base.
Does a French drain need a sump pump?
Only when gravity can't finish the job. A drain that can discharge downhill — to daylight, a storm drain, or a dry well — needs no pump. Flat lots often do, and interior basement systems almost always do (there's no downhill inside a basement): the drain feeds a sump basin and a pump ejects the water, adding $600–$2,500 to outdoor systems and coming included with basement perimeter installs. If your lot has any usable slope, use it — gravity never loses power in a storm.
What is the difference between a French drain and a trench drain?
What they catch. A French drain is a buried, gravel-wrapped perforated pipe that collects subsurface water — the water already in your soil. A trench drain (the channel with a grate you see in driveways) catches surface runoff before it soaks in. Soggy lawn or wet basement: French drain. Sheet of water crossing the driveway toward the garage: trench drain. Serious drainage fixes sometimes deploy both, each doing its own layer.
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