Installing a small French drain usually doesn't require a permit. If your drain will be diverting water into a municipal drain or sewer or your property has a shallow water table, you may need a building permit. A professional French drain installer will take care of getting any permits the project needs.
In some cases, the installation of a French drain may require planning permission from your local planning authority, especially if the drain is part of a larger construction project. You should consult your local planning authority for guidance on any necessary permissions and requirements.
Depending on the size of your yard and the scale of your drainage issue, you can purchase the pipes and equipment to create a French drain yourself.
Landscapers commonly install French drains to solve water problems in the yard. A basement waterproofing company or one of the best foundation repair companies (such as Basement Systems or Olshan) can tackle drainage problems around the home's perimeter.
In general, a French drain placed 1-3 feet away from and parallel to the foundation will work great, and reduce the risk of foundation issues tremendously. However, if moisture is coming up through the floor (meaning water is seeping down and around the foundation) the solution may change.
Permits Needed to Install a French Drain
Generally, a small French drain on your property that doesn't change the flow of runoff entering and exiting your yard won't need a permit. Major projects that warrant your French drain to discharge into a municipal sewer or roadside ditch, however, do require one.
Clay soil has poor permeability, meaning it doesn't allow water to pass through easily. In such cases, the effectiveness of a French drain may be limited as the water may struggle to drain away from the area efficiently. French drains may not be suitable for areas with high water tables.
Installing a French drain costs $500 to $18,000, with a national average of $9,250. On average, you can expect to pay $10 to $100 per linear foot, or between $500 and $5,000 to have a 50-foot French drain installed.
Benefits of Installing a French Drain
By redirecting water away from your home's foundation, French drains help keep basements and crawl spaces dry, reducing the risk of structural damage and mold growth.
French drain depth: About 8 inches to 2 feet deep should be sufficient for many water-diverting projects, though related systems, such as those built around foundations and sub-ground living spaces, as well as the bases of retaining walls, may be deeper.
Swales: A Natural Solution
They're a great option if you're looking for a more natural, eco-friendly alternative to French drains. A swale is typically lined with grass or vegetation that helps slow down and absorb water.
Connections to a public sewer are called direct connections. If you want to connect to a private drain, you will also need to obtain permission from the drainage owner. Connections to a private drain are called indirect connections. Moving a public manhole is called manhole relocation.
Connect with local French drain experts to help with your project. Installing a French drain yourself is possible but labor-intensive and time-consuming. Call 811 a week or two before you start your project to get your buried utility lines marked.
A properly designed French drain system does not require an outlet. The water will simply soak into the soil as it flows along the perforated pipe. In fact, a French drain doesn't require an inlet on just one end either. You can construct the drain to accept water along its length, and disperse it underground.
With stormwater, most likely, your drainage systems would fall under land improvements. Stormwater best management practices such as french drains, downspouts and gutter systems, bioswales, and dry wells could qualify as depreciable assets.
Generally speaking, a French drain will last approximately 30 to 40 years. However, the above-mentioned factors may shorten its life cycle and it must then be replaced by a team of foundation experts.
French drains are an invaluable asset for any homeowner. Their effectiveness in managing water, preventing erosion, protecting homes, and increasing property value make them a worthwhile investment.
Aside from what we've listed here, the difference between a French drain and a trench drain is that a French drain is used for water that is underground while a trench drain diverts excess water from a surface.
Interior French drains are meant for waterproofing the basement or draining your crawl space. They cost more because contractors must tear out the basement floor (most often made of concrete), install the drain, and then repair it.
French drains aren't meant to be installed and forgotten about. Just like other types of drains, they are susceptible to clogging over time.
Although French drains are low-maintenance, they are not entirely free of potential issues. Over time, the system can become clogged with silt, roots, or debris. When this happens, water may pool again in areas the drain was meant to protect. Regular inspections can help identify problems early before they escalate.
Distance from Foundation
A general rule of thumb is that a french drain should be installed around three feet away from the foundation of a home, but this can vary depending on individual landscaping factors such as where the water is pooling and where gutters are already aligned.
The optimally installed French drain does not necessarily need an end point. Ideally, as the excess water from one area runs down the drain, it will be distributed more evenly across your yard and absorbed.