How much does a French drain cost?

While the average rate for piping and installation to build a french drain is approximately $25-$50 per linear foot, the total amount may increase or decrease depending on the job’s complexity, whether you're redirecting interior or exterior water and what kind of piping you use.

As previously stated, installing a French drain indoors (like in your basement) or outdoors will likely incur different costs. Typically, internal drainage systems are more expensive than outdoor ones. Here are some examples of the cost per linear foot for French drain installation from a Thumbtack pro and drainage contractor in Michigan:

When you're installing a French drain, a pro can help you determine how much French drain pipe you need to lay to redirect the water far enough away from your home. 

A French drain is an underground water drainage system that redirects free-standing water from your basement or crawl space, around your home's foundation or from low areas in your backyard or driveway. Essentially, this drainage system can prevent heavy rain and floods from causing water damage.

Interior vs. exterior French drainage systems

An interior French drain redirects water that enters your basement. A contractor can install the drain under your basement floor. 

An exterior French drain moves water away from low spots where it collects in your backyard. These drains are useful behind exterior retaining walls to prevent water from pooling and damaging a wall's structural integrity over time.

How does a French drain work?

French drains use gravity to redirect water to a lower location downstream from your home. A French drain's perforated pipes (aka “weeping tile”) drain groundwater and standing water near your foundation or in your basement to a new location. The French drain descends at a slight slope, and the water exits at a lower point away from your home, such as a drywell, a dry creek bed, the street or a storm drain.

Not sure if you need to install a French drain system? If any of the following statements apply to you, you should consider installing one:

• You live in a region that gets a lot of rain.
• Your lawn is too wet or squishy after it rains.
• It takes a long time for your property to dry after it rains.
• You want to build a retaining wall that’s located on a hill.
• Your basement is experiencing water or flooding problems.
• You don’t have a drainage system, and your basement is prone to flooding.
• You have a drainage system, but your basement is still having flooding issues.

Talk to a contractor near you to determine if a French drain is the best type of drainage system for your property.

There are other factors to consider besides the total linear feet when estimating prices. Here’s an overview of the main factors that can impact the cost of a French drain:

Labor rates

Installing a French drain requires manual labor. The contractor(s) will need to dig a trench, lay down the pipes and add a layer of gravel. The more labor-intensive the installation process, the higher the cost.

Keep in mind that creating a French drain to redirect water from a finished basement involves cutting into the basement slab, removing interior walls and reinstalling your basement floor.

Site accessibility

The harder it is to access and navigate the site where you need to install the drainage system, the higher the price. 

Soil content

If your soil has shale or other conditions that make it hard to dig, that may increase the amount of time it takes to complete the project (and thus, the cost).

French drain pipe material

When choosing a material for your French drain pipe, your options are typically rigid PVC with holes or flexible drain pipe with slits. Flexible pipe is typically the most affordable option, according to Bob Vila.   

Sump pump

Installing a new sump pump costs approximately $400-$1,397. An interior French drain system directs water from underneath the basement floor to a collection pit. A sump pump will then pump it to the surface. If you don’t have a sump pump, you’ll need to install one (or repair your broken one). 

French drain depth

Depending on what the conditions are in your yard or basement, you may need a deep or shallow French drain. A shallow French drain (or a “curtain drain”) costs about $10-$16 per linear foot and is recommended if you only have a surface water issue, according to House Logic. For example, you may need a shallow French drain if you have a squishy, overly wet lawn. These drains are about 2 feet deep.

A deep French drain (aka a footing drain) costs approximately $12,000 for a 1,500-square-foot basement that’s 6 feet deep. A deep French drain runs around your home’s perimeter to redirect the water before it invades the basement.

Installing a French drain consists of four main steps: mapping out the drainage path, digging the trench, laying the piping and refilling the trench.

First, a drainage pro will assess your issues to see how far your exit point needs to be from your home and determine your French drain design. 

Next, a pro will dig a trench. For an interior French drain system, this means cutting into your basement floor. Once the trench is dug, your pro will line the trench with landscaping fabric and lay the perforated piping. Then, they'll test the system from your home to confirm the water is deposited at the exit site. 

Lastly, the pro will cover the piping with gravel and refill the trench with soil to hide it underground. Sometimes, a pro will cover the drain with a grate or leave it uncovered.

Pro tip: Find out what utility lines are underground. A contractor may need to design a more nuanced drainage system to avoid your utilities. 

Your French drain doesn't require much maintenance to operate well. However, it can get clogged when leaves and debris accrue over time. Flushing your drain with a hose and occasionally snaking your drain with an electric sewer snake can keep it running properly.

When you notice a slight clog in your French drain, clear it right away to avoid a larger problem.

Also read: Plumbing maintenance tips.

Installing a French drain can get complicated quickly, so it’s best to hire a professional to install your system. You can find local professionals on Thumbtack, where you can also read their customer reviews and ratings.

When you’re chatting with potential contractors, ask about their credentials. Ensure ahead of time that they're comfortable with outdoor jobs, and always ask for photos or examples of past work they’ve completed. 

For more tips, read our guide on how to hire a contractor.

When you have a water drainage problem, it's important to find a solution as quickly as possible. Thumbtack's helpful and knowledgeable drainage pros can help you waterproof your basement, dry your backyard and redirect unwanted water away from your home.