How much does a French drain cost?

HomeGuide's February 2026 national figures put a yard or curtain drain at $10 to $35 per linear foot, and a curtain drain at $1,500 to $8,800 in total. An exterior footing drain dug to the base of the foundation runs $30 to $90 per foot, about $1,200 to $4,500 per side of the house. We haven't found Michigan-only numbers.

How deep should a French drain be?

It depends on the job. HomeGuide's guide puts a typical yard drain 12 to 24 inches deep and at least 12 inches wide. Curtain drains go 2 feet or deeper to catch groundwater. A footing drain sits at the bottom of the foundation, and Michigan footings are at least 42 inches below grade, so that trench is deep.

How long does a French drain last?

HomeGuide says most French drains last 30 to 40 years or more when they're built right. Silt is what shortens that, which is why fabric around the gravel matters on clay. Soil with iron ochre clogs pipes faster and needs more frequent cleaning. Cleaning a clogged line costs $80 to $500 or more nationally.

Where can a French drain empty in Farmington Hills?

Somewhere lower on your own lot, a dry well, a sump or a storm drain. It can't go into the sanitary sewer: city ordinance bans groundwater and surface water from it. A footing drain that runs to a sump follows the city's sump discharge rule, at least 4 feet from the foundation and away from the neighbors and the street.

Do I need a permit for a French drain?

HomeGuide notes most areas require one, at $100 to $375 nationally, more for a storm-drain connection. Farmington Hills' permit page doesn't list French drains by name, so ask the Building Division at (248) 871-2450. MISS DIG 811 is required either way: a free ticket at least three business days before digging.

French Drain Installation in Farmington Hills, MI

Types of French Drain Installation

Deep trench beside a poured concrete basement wall with perforated PVC drain pipe on washed gravel at the footing

Exterior Footing French Drains

A footing drain, also called weeping tile or drain tile, runs along the outside of the footing at the bottom of the basement wall. It's the drain the residential code expects around every concrete or block basement: perforated pipe on at least 2 inches of washed gravel, covered by at least 6 inches more, emptied by gravity or a pump. On a house where the original tile has silted up or collapsed, a new one means digging to the footing, at least 42 inches down in Michigan. We'd use rigid PVC rather than corrugated pipe here; HomeGuide's guide points the same way, because PVC is more durable and takes a plumber's snake. With the wall dug open, it's also the time to add a membrane, covered under exterior basement waterproofing.

Shallow gravel trench wrapped in black filter fabric running across a wet lawn, with a perforated pipe in the gravel

Yard French Drains

A yard drain catches water that soaks a lawn and stays there. HomeGuide's guide puts a typical one 12 to 24 inches deep, at least 12 inches wide and 2 to 5 feet from the foundation. On clay the soil gives water up slowly, so the trench does its work by giving water an easier path than the ground around it. Corrugated pipe is fine at this depth and bends around beds. If the wet spot is surface runoff rather than saturated soil, grading or a catch basin may fix it more cheaply, which is what yard drainage covers.

Narrow gravel-filled trench cut across a sloped back yard uphill of a brick house, with sod rolled back on either side

Curtain Drains

A curtain drain is the same build placed across a slope, uphill of the house, to cut off water moving through the soil before it reaches the foundation. HomeGuide describes it as 2 feet or deeper, mostly carrying groundwater, and usually covered with sod so it disappears into the lawn. It suits a house at the bottom of a rise or below a neighbor's yard, where water arrives sideways through the ground rather than from the roof.

Round green pop-up drain emitter set in a lawn at the end of a buried drain line, slightly open with water flowing out

French Drain Outlets: Daylight, Dry Well or Pop-Up Emitter

The three common outlets are daylight (the pipe exits on a lower part of the lot), a dry well (a buried gravel pit or tank that lets water soak in), and a pop-up emitter, a lawn fitting that opens under pressure. Code lets subsoil drains end at a sump, a dry well or an approved spot above ground. A dry well needs soil that drains, which slow clay often doesn't, so the contractor should test before relying on one. HomeGuide puts a perc test at $600 to $2,000.

Gloved hands holding a moisture meter against a hairline crack in a poured concrete basement wall, lit by a flashlight

Why Farmington Hills homeowners call Farmington Hills Waterproofing

Free in-home inspection
Written scope and price before work starts
Cause found before a fix is quoted
One local waterproofing contractor, not a call list
No charge to homeowners for the referral

How a French Drain Is Built

These are the details to look for in the quote. A drain that skips one of them can silt up or hold water.

Slope
At least 1% the whole length, a foot of fall per 100 feet, with no dips that hold water.
Fabric
Non-woven geotextile lining the trench and folded over the gravel. A sock on the pipe alone leaves the gravel open to silt.
Gravel
Washed stone, 2 to 3 inches under the pipe and 3 to 4 over it in a yard drain. Code asks 2 under and 6 over at a footing.
Pipe
At least 4 inches. Corrugated for shallow, curving runs; rigid PVC such as SDR 35 for deep footing drains.
Cleanouts
An access point so the line can be snaked or flushed later.
Outlet
Lower ground, a dry well, a sump or a storm drain, decided before the trench is dug.

Where the Water Can Go in Farmington Hills

City ordinance makes it unlawful to send groundwater, roof water or surface water into the sanitary sewer. The legal outlets for footing drain water are the storm sewer and the ground surface. On the surface, the outlet has to sit at least 4 feet from the foundation, can't send water over a neighboring parcel, and stays out of the street right-of-way and the 20 feet beside it. The city's grading rule asks for a 5% slope away from the house for the first 10 feet, so a drain that dumps water next to the foundation is working against it. Before any trench, the contractor calls MISS DIG 811 at least three business days ahead, and digs by hand within 4 feet of the marks.

French Drain Cost and Lifespan

All figures are HomeGuide national ranges from February 2026; we couldn't find a Michigan breakdown.

Drain	Per linear foot	Typical total
Yard or curtain drain	$10-$35	$1,500-$8,800 (curtain)
Exterior footing drain	$30-$90	$1,200-$4,500 per side
Dry well outlet	n/a	$50-$3,000+
Permit	n/a	$100-$375

In HomeGuide's estimate, a well-built French drain lasts 30 to 40 years or more. Soils with iron ochre clog drain lines faster and need cleaning more often, at $80 to $500 or more a visit.

French Drain Installation in Farmington Hills

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