French Drain Installation Cost in 2026 — The Per-Foot Rate, and What It Leaves Out

A French drain quote arrives as one number for the whole job, and the per-foot rate that produced it is almost never shown. That rate is set by one thing: how deep the trench has to be. Everything else that moves your final bill is sitting outside the rate entirely, in the items a per-foot price quietly assumes it does not have to cover.

Depth is the rate

Three fairly different jobs get sold under the same name, and they price like three different jobs:

• Shallow yard drain, 10–12 inches: about $10–$30 per linear foot, typically around $20. This is the fix for a corner of lawn that stays soupy for two days after rain.
• Standard French drain, 18–24 inches: about $25–$60 per foot, typically around $40. This is the workhorse, used to catch water heading toward a foundation, a patio, or a crawlspace.
• Deep or curtain drain, 3 feet and up: about $40–$90 per foot, typically around $65. This one intercepts groundwater moving downhill toward the house before it ever gets there.

Those are installed prices, and they cover the full sandwich: trenching, filter fabric, perforated pipe, washed drainage gravel, backfill, and basic cleanup. The French drain cost calculator puts your length and depth against those rates and adjusts for your state.

The jump from shallow to deep looks steep until you picture the trench. Tripling the depth triples the soil coming out, triples the gravel going back in, triples the spoil somebody has to wheelbarrow or truck away, and usually means slower, more careful digging because you are now working next to a footing or a utility. The perforated pipe, the part everyone pictures when they hear “French drain,” is the cheapest item in the trench at any depth.

A 50-foot run, costed out

Fifty feet is a common real-world length: the wet side of a house, or a run from a low spot out to the street.

At standard depth, that is $1,250 to $3,000 nationally, with a typical bid landing near $2,000. The same 50 feet shallow is closer to $500–$1,500. Dug as a deep curtain drain it is $2,000–$4,500.

Two things then move the national number. First, labor is about 65 percent of it — roughly $1,300 of that typical $2,000 is crew time and machine time, not material. Second, because labor is the bigger half, where you live moves the bill. State cost factors on this site run from about 0.86 in the lowest-wage states to 1.28 in Hawaii, so the same $2,000 typical run prices near $1,720 in Alabama and about $2,560 in Hawaii for identical work.

What the per-foot rate does not include

This is where estimates and final bills part company. None of the following is inside the per-foot number:

• A sump pump, when there is nowhere downhill to send the water. Gravity is the entire operating principle of a French drain, so a flat lot with no daylight outlet needs a pump and basin: $625–$2,625 on top.
• Dry wells and catch basins. If the discharge has to go into a buried chamber rather than out to a curb or a slope, that structure is priced separately.
• Cutting through a driveway, walk, or patio so the pipe can cross it. Sawing and patching hard surfaces is its own trade and its own line item — the concrete slab calculator will give you a sense of what replacing that strip costs.
• Landscape repair over the trench. You are left with a strip of bare, settling dirt across the yard. Re-sodding or seeding it is normally on you; price that strip with the sod cost calculator.
• Interior basement perimeter drains. Different system, different price: $40–$100 per linear foot, because it means breaking out slab, trenching inside the footing, and patching concrete. Our calculator is exterior-only on purpose.

Ask which of these apply before you compare bids. A cheap-looking quote that stops at the property line while an expensive one includes the pump, the basin, and new sod is not actually a cheaper quote.

Why two bids on the same trench land $1,000 apart

Same yard, same length, same depth, and the numbers still spread. Usually one of four things is behind it:

Soil. Clay is slow. Rock is slower and sometimes means a hammer attachment instead of a trencher. A yard full of mature tree roots turns machine work into hand work in stretches.

Distance to a legal discharge point. The drain has to end somewhere water is allowed to go. If daylight is 15 feet away on a slope, that is cheap. If the nearest legal outlet is 80 feet across the yard, you are paying for 80 feet of extra trench that does no collecting at all.

Access. A trencher that can drive around the house is a different bid from a gate too narrow for equipment, where the whole run gets dug by hand.

What is actually going in the trench. The single most common reason a drain fails is silt clogging the pipe, because the filter fabric was skipped or the gravel was not washed. Those two items are cheap to omit and invisible once the trench is closed. A bid that comes in well under the range is worth a specific question about both.

Digging it yourself

The materials are genuinely inexpensive, which makes this one of the more tempting DIY jobs in the yard.

For a standard-depth drain, expect roughly $10–$23 per linear foot in perforated pipe, filter fabric, washed gravel, and trencher rental, so a 50-foot run is about $500–$1,150 against $1,250–$3,000 installed. A shallow yard drain is around $4–$12 per foot in materials.

The honest caveats:

1. Call 811 first. Utility locates are free and not optional. Cutting a gas or fiber line with a rented trencher is a very expensive afternoon.
2. Slope is the whole job. The pipe needs a consistent fall of about an inch every 8 to 10 feet toward the outlet. Eyeballing it is how drains end up holding water instead of moving it.
3. Spoil has to go somewhere. A 50-foot standard trench produces a surprising pile of dirt, and hauling it is real work you have not budgeted for.
4. Depth changes the answer. A shallow run across soft lawn is a reasonable weekend. Anything hugging a foundation, cutting through rock, or running 3 feet deep is where the rented machine stops saving you money.

If the water problem starts at a wall rather than in open lawn, drainage is half of that job too — the retaining wall calculator covers the gravel, fabric, and weep-pipe side of wall pricing.

Five things to confirm before you sign

• Where does the water go? The discharge point should be named on the estimate, not assumed.
• Is filter fabric and washed gravel specified? In writing.
• What is the trench depth? It is the price lever, so it belongs on the paper.
• Who restores the lawn? And is sod or seed included, or is that your Saturday?
• Does the run cross anything hard? Driveway and walkway cuts should be priced before work starts, never discovered mid-job.

Run your own length and depth through the French drain calculator before the first contractor walks the yard. Walking out with a number already in your head changes the conversation, and if the drain is one piece of a larger yard project, the budget planner will total it against the rest.

Frequently asked questions