How much does a 200 ft french drain cost?

At the national exterior range of $10 to $75 per linear foot, a 200-foot yard drain lands roughly between $2,000 and $15,000, with most residential jobs toward the lower half. Depth, soil, and the outlet decide where you fall. A drain that long usually means a serious water problem, so get the layout designed, not just priced.

What is the average cost for a 100 ft french drain?

Published national figures put a 100-foot exterior french drain around $1,000 to $7,500 installed, depending on depth, soil, and where the water exits. Interior perimeter systems are a different animal at $40 to $100 per foot. On the Northshore, plan for the wet-season water table to shape the design.

Is it expensive to put in a french drain?

Compared to regrading a low spot or extending downspouts, yes, a french drain is the bigger investment. Compared to repairing a flooded slab foundation or living with a swamp for a back yard, it is cheap. Most exterior projects nationally land in the $2,800 to $6,500 range.

Are french drains worth the money?

When the problem is subsurface water or a yard that stays saturated, a properly built french drain is one of the few fixes that actually works. When the problem is surface runoff from bad grading, regrading or a catch basin may solve it for less. Worth it starts with the right diagnosis.

Do french drains work in clay soil?

Yes, and around here they have to. Clay drains slowly, which is exactly why the trench, gravel, and perforated pipe exist: they give water a faster path than the soil provides. Clay makes digging slower and makes the fabric wrap more important, since fine particles will clog an unprotected drain over time.

How deep should a french drain be in south Louisiana?

A typical yard drain runs 18 to 24 inches deep. On St. Tammany's terrace soils the winter water table can sit 1 to 3 feet down, so a drain at that depth may run for weeks at a time and needs a true gravity outfall, a ditch, swale, or daylight point, rather than counting on the ground to soak water up.

How much does a french drain cost in the Northshore area?

Nationally, an exterior french drain runs about $10 to $75 per linear foot installed, and most yard projects land between $2,800 and $6,500. Interior perimeter systems cost more, $40 to $100 per foot. No major cost guide publishes a Louisiana-specific number, so treat those national ranges as the honest baseline and expect your exact price to come from the lot itself.

That last part matters more here than most places. Around Covington, Mandeville, and the rest of St. Tammany Parish, the ground is flat, the rain is heavy, and the winter water table rides high. All three change how a drain gets designed, and the design is what sets the price.

What a french drain costs by type

Type	Typical installed cost	Notes
Curtain drain (shallow)	$10–$25 per linear foot	Intercepts surface and shallow water
Exterior yard drain	$10–$75 per linear foot	The common backyard fix; most projects $2,800–$6,500
Exterior around the foundation	$10–$50 per linear foot	Roughly $500–$10,000 per project
Interior basement perimeter	$40–$100 per linear foot	$5,000–$18,000; involves breaking concrete

Those figures come from the major national cost guides, HomeAdvisor, Bob Vila, LawnStarter, and Lawn Love, all current within the last two years. They agree on the shape of the market even where the exact numbers differ. Since south Louisiana homes skip basements, almost all Northshore work is the exterior kind, which is the cheaper half of the table.

What drives the price up or down

Five things move the number more than anything else:

Length. Drains price by the foot, so a 40-foot problem costs a fraction of a 150-foot one.
Depth. A shallow curtain drain is quick work. A deep drain protecting a slab takes more digging, more gravel, and more pipe.
Soil. Clay digs slow and holds water. Labor rates of $50 to $100 per hour per worker add up faster in heavy ground.
The outlet. Water has to go somewhere legal. Daylighting to a ditch or swale is baseline. When gravity will not carry it, a sump pump adds roughly $500 to $2,600.
Permits and restoration. Permits generally run $50 to $225 where required, and re-sodding the scar costs about $0.90 to $1.80 per square foot.

One Northshore-specific driver deserves its own line: the outfall. St. Tammany’s own hazard planning describes flat terrain where ponding collects in clay-lined low areas that cannot drain. If your lot has no natural fall, getting water to a ditch or street legally is the design problem, and solving it is where the money goes.

Why the Northshore water table changes the design

On the parish’s terrace soils, the seasonal water table sits about 1 to 3 feet below the surface from December through April. A standard 18-to-24-inch drain spends part of the winter sitting in groundwater, which means it will run almost constantly in the wet months. That is fine, that is the job, but only if the drain has a genuine gravity outfall. A drain that dead-ends into a gravel pit expecting the soil to absorb water will fail here, because in January the soil is already full.

Add the rain math and the picture is complete: Slidell averages 66 inches a year, Hammond 64, and southeast Louisiana overall runs among the wettest regions in the country, with 4-inch rain days hitting record frequency in recent years. A drain built for Atlanta conditions is undersized for ours. This is why we design the outfall first and the trench second on every drainage project we build.

Cheaper fixes worth pricing first

A french drain is the right tool for subsurface water. If your problem is surface water, one of these may solve it for less:

Fix	Typical cost	Best for
Downspout extensions	Minimal	Roof water dumping at the slab
Regrading	$500–$4,000	Yards pitched toward the house
Catch basin	$20–$130 per basin plus piping	Collecting water at a low point
Dry well	$500–$3,000	End-of-line storage, where soil allows
Sump pump	$500–$2,600	Water with nowhere to gravity-drain

Around here, regrading and french drains often work as one project, shape the yard to move surface water, and let the drain handle what soaks in. Since we do our own grading and dirt work, we quote it as one scope with one crew, which usually beats hiring the fixes separately.

Getting a real number for your yard

The honest answer to “what will mine cost” is a walk around your lot: where the water stands, where it can exit, how deep the trench needs to run, and what the soil is doing. That takes about twenty minutes and costs nothing. If the yard has been a swamp since Christmas, that is normal for this parish, and it is fixable. Reach out for a free estimate and we will design the drain around how your ground actually behaves.