French Drain Cost Guide: 2026

Ask three contractors what a French drain costs per foot and you will get three wildly different numbers — and all three might be honest. That is because “French drain” is one name for at least five different jobs: a shallow yard trench that takes an afternoon, a deep exterior trench to the foundation footings that takes a week, and an interior basement perimeter system that requires breaking up your concrete floor. The price follows the depth, the location, and the access — not the name.

This 2026 cost guide breaks French drain pricing down per linear foot by type, shows total project costs for common lengths, names the cost drivers that move quotes, explains what an itemized quote must include, and flags the outlet problem that turns cheap drains into expensive disappointments. Price the water problem first, then the trench.

French drain cost per foot in 2026, by type

These are installed 2026 US market ranges from current contractor pricing data. The tenfold spread is not vagueness — it is five different jobs sharing one name:

Which job you mean	Cost per linear foot	Typical total	What it is
Shallow yard / surface drain	~$10–$35	~$500–$5,300	Trench under ~2 ft deep collecting surface water
Curtain drain	~$10–$25	~$1,500–$8,800	Shallow uphill interceptor catching water before it reaches the house
Exterior footing drain (deep)	~$30–$90	~$1,200–$4,500+ per side	Excavated to foundation depth; the depth is the cost
Interior basement perimeter	~$40–$100	~$4,000–$17,000	Concrete floor broken, tile laid, floor re-poured; sump required
Interior crawl space	~$20–$40	~$2,000–$8,000	Same concept, no concrete demolition

Costs are 2026 US market ranges; get itemized local quotes.

Depth is the single biggest driver. A shallow exterior trench is mostly a day of digging; the same trench taken to the footings is priced by the cubic yard of excavation. Interior basement work adds concrete demolition and re-pour, dust control, and a sump pump — which is why interior per-foot pricing runs roughly triple the shallow yard rate.

Total project costs by length

Per-foot math is useful, but contractors price the whole job. For planning, here is how common lengths translate for the two most-quoted types:

Length	Shallow exterior (~$10–$35/ft)	Interior basement (~$40–$85/ft)
50 ft	~$500–$1,800	~$2,000–$4,300
100 ft	~$1,000–$3,500	~$4,000–$8,500
150 ft	~$1,500–$5,300	~$6,000–$12,800
200 ft	~$2,000–$7,000	~$8,000–$17,000

A 100-foot basement perimeter — roughly a 20-by-30-foot basement — is the classic reference job: expect the mid-single-thousands at the low end and into the teens of thousands with a premium sump, battery backup, and wall membrane included. Interior systems essentially always include the sump pump in the project scope; if a quote does not, ask where the water goes.

The outlet: the part everyone underprices

A French drain is a sloped trench with perforated pipe and stone that moves water to an outlet — and the outlet is where budgets die. If your lot has slope, the pipe can daylight downhill for nearly nothing. If it does not, you need a sump pump to lift the water (roughly $800–$3,000 installed for the pump portion), a dry well, or a connection to a storm sewer — and the outlet can add anywhere from a few hundred to $5,000+ to the project. A drain with nowhere to go is a buried bathtub; confirm the outlet plan before approving any trench work.

Restoration is the second underpriced line item. Sod, mulch, paver resets, and regrading typically add 15–30% to exterior projects and are frequently billed separately. A quote that looks 25% cheaper than the others often just omitted restoration — compare line items, not bottom lines.

What drives the price up (or down)

• Depth and soil. Rocky soil, clay, or a high water table slow excavation and multiply labor. Deep footing drains cost triple shallow ones for this reason alone.
• Access. Tight side yards, fences, mature trees, and utilities in the trench path all add hours. Call 811 for utility locates before anyone digs — it is free and legally required in most states.
• Concrete and finishes. Interior work means breaking and re-pouring the slab; finished basements add protection, dust control, and repair of any disturbed finishes.
• The sump pump. New pump, basin, battery backup, and alarm add roughly $800–$3,000+ to interior projects that cannot drain by gravity.
• Permits and engineering. Many municipalities require permits for drainage work, especially exterior work near foundations or connected to storm systems — typically $50–$250, handled by the contractor.
• Regrading. If the site slope sends water toward the house, regrading can add $500–$5,000 — but it is often the actual fix, with the drain as the complement.

What an itemized quote must include

Never accept a single-line “install French drain” price. A legitimate quote itemizes: linear footage and trench depth; pipe type and diameter; stone type and volume; filter fabric (the sock that keeps the pipe from silting up — its absence is a classic corner-cut); the outlet plan and termination point; sump pump make, model, and horsepower if included; battery backup and alarm; concrete demolition and re-pour square footage for interior work; restoration scope; permits; and warranty terms. Two quotes at the same bottom line can describe very different systems — the itemization is the only way to compare.

Watch for the red flags: a quote far below the per-foot ranges above (corners are being cut — usually fabric, stone depth, or outlet), no mention of the outlet at all, no permit handling, and pressure to decide before a rain “proves” you need it. Good drainage contractors are busy in the dry season too; urgency is a sales tactic, not a weather forecast.

DIY vs. hiring a pro

A shallow yard drain in open, utility-free ground is a legitimate DIY project: rent a trencher, buy perforated pipe, stone, and fabric, and spend a weekend. Material costs run a few dollars per foot, and the main risk is a drain that does not slope correctly — rent a laser level and check fall continuously, because a flat drain is a French pond.

Everything else belongs to licensed professionals. Deep exterior trenches near foundations risk undermining footings, collapsing trench walls, and utility strikes. Interior basement systems involve concrete demolition, foundation-adjacent trenching, electrical work for the pump, and permits — this is licensed basement-waterproofing-contractor territory. The cost of fixing a collapsed trench or a undermined footing dwarfs any DIY savings.

Pipe, stone, and fabric: what good materials look like

Most of a French drain’s cost is digging, which tempts contractors to economize on the materials nobody will ever see — and material shortcuts are why drains fail in five years instead of fifty. Know what “done right” looks like so you can spot it in a quote. The pipe should be perforated, rigid or semi-rigid PVC or corrugated HDPE in 3- or 4-inch diameter, with the perforations facing down — water rises into the pipe from below through the stone bed, a detail inexperienced installers get backwards. Solid pipe has no place in the collection run (it belongs only in the solid outlet run carrying water away).

The stone should be washed, angular drainage aggregate — typically 3/4-inch clean gravel — not pea gravel, not crusher run, and never soil backfill around the pipe. Fines and rounded stone clog and compact; angular washed stone holds its voids open for decades. The trench should carry several inches of stone below the pipe and above it. And the entire assembly — stone and pipe together — should be wrapped in geotextile filter fabric, burrito-style, to keep surrounding soil from migrating into the stone and silting the system shut. Fabric is the most commonly skipped component and the cheapest insurance in the trench; its absence on a quote is a reason to keep shopping, not a reason the quote is attractively priced.

Slope is the invisible fourth material: the pipe needs continuous fall toward the outlet — roughly 1% (an eighth-inch per foot) at minimum — verified with a level during installation, not eyeballed. A drain with a belly or a high spot holds water permanently, breeds sediment, and fails from the middle out. Ask the contractor how they verify slope; “we eyeball it” is a disqualifying answer.

Maintenance: keeping the drain flowing for decades

A properly built French drain is nearly maintenance-free, but “nearly” still includes three habits. First, keep the outlet clear: walk the discharge point each spring and fall, clearing leaves, mulch, and sediment from daylight outlets and confirming sump-driven outlets still pump freely. A blocked outlet backs the entire system up silently. Second, protect cleanouts: insist the installer include vertical cleanout risers at the high end and at long runs, capped at grade — they are the access points for flushing the line with a garden hose every few years, which is the entire maintenance program for a residential drain.

Third, watch what happens uphill: new landscaping, regrading, patios, or a neighbor’s changed drainage can redirect far more water at your drain than it was designed for. A drain sized for your roof and yard in 2026 can be overwhelmed by the addition uphill in 2029. If surface water patterns change, reassess before the next storm season rather than after the basement tells you. And never drive heavy equipment over a shallow drain — crushed pipe under a delivery truck’s path is a depressingly common service call.

Matching the drain to the water problem

The most expensive French drain mistake is installing the right drain in the wrong place — so match the type to the diagnosis before comparing prices. Surface water ponding in the yard away from the house calls for a shallow yard drain or curtain drain daylighted downhill: the cheapest job on the menu. Water seeping at the basement wall or the floor-wall joint calls for either a deep exterior footing drain (stopping it outside) or an interior perimeter system (managing it inside) — the two expensive options, chosen by budget, disruption tolerance, and yard access. Water entering through a single crack calls for crack injection, not a drain at all.

Two scenarios deserve special mention. On sloped lots, a curtain drain cut across the slope uphill of the house — shallow, cheap, often under $25 per foot — intercepts subsurface water before it ever reaches the foundation, and it is the highest-return drainage dollar on a hillside property. In finished basements, the interior perimeter system is usually the pragmatic winner despite the concrete work: no landscaping destroyed, no weeks of excavation, and the sump pump at its heart protects the finished value below. Diagnose first, then price the drain that matches — in that order, every time.

Getting quotes and getting it done

Start by defining the water problem in one sentence — surface water ponding in the yard, seepage at the basement wall, water at the floor-wall joint — because the sentence picks the drain type, and the drain type picks the price. Get two to three itemized quotes from licensed drainage or waterproofing contractors, confirm the outlet plan and utility locates, and schedule exterior work for the dry season when ground is workable and crews are available. The cheapest drain is the one installed once, in the right place, with somewhere for the water to go.