Dry Well vs. French Drain: 8 Key Differences and How to Choose the Best One for You

Written by Angie Menjivar
Published: October 31, 2023
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You need to set up some kind of drainage system but you’re not entirely sure which option is best between a dry well vs. a French drain. Both of these options aid in waterproofing your home but they work in different ways and are designed with specific purposes in mind. Discover eight key differences between the two to gain a better understanding of how each works!

Key Differences Between a Dry Well vs. French Drain

Dry WellFrench Drain
DesignLarge hole with a basic that serves as an underground reservoirSmall trench with the use of a perforated pipe and filled with gravel
PurposeHolds water temporarily until it slowly soaks deep into the groundChannels water away starting at the surface level
Installation LocationTypically larger areas like yards where water can settle into the groundOften near foundations to prevent flooding
Water CapacityDesigned to hold large amounts of water while it drains slowlyNot meant to hold water, but rather redirect it
Water DisposalHolds water for a period and releases it deep undergroundMay be redirected to the ground and typically lower-lying areas
MaintenanceRequire maintenance to ensure there are no clogs and the filtering system remains efficientAfter initial installation, maintenance is low, requiring yearly cleanings on average
Flow ControlThey are best for heavy rain as they have high water capacity but the flow into the ground is slowIdeal for handling runoff as they keep water moving
CostTypically higher than a French drainUsually more affordable than a dry well

Dry Well vs. French Drain: 8 Key Differences and How to Choose the Best One for You

There are eight key differences between a dry well and a French drain that you should know before you decide on either for your property. Each one is designed differently, has a different purpose, and is typically installed in a different location around your property. While one has the capacity to hold water, the other is only designed to let water run through it.

One may need more regular maintenance while the other is considered more low maintenance, requiring yearly cleanings. Additionally, flow control is different as one keeps water moving continuously while another is slower, letting water percolate. The final difference is the cost and there are a lot of variables that go into the total, which is why working with a professional is your best bet.

Dry Well vs. French Drain: Design

A dry well is a large, deep hole designed to catch any heavy rainfall and slowly distribute it into the soil below. These larger wells are meant to collect water, not so much to channel it away. The design ensures there’s a basin to collect the water and it also allows for percolation.

Water Well Drilling, Dig a well for water, Inside The Well, Groundwater hole drilling machine, boreholes, Deep pit in the ground

A dry well can hold water temporarily and slowly release it deep into the ground below.

©I am a Stranger/Shutterstock.com

A French drain is designed in a way that utilizes the force of gravity. Its design requires some digging though not nearly as much as a dry well. A trench is created, and a perforated pipe is inserted to collect any of the excess water that runs off from your property. The trench is then filled with something permeable like gravel so the water can easily enter the pipe and get directed away from your foundation.

Dry Well vs. French Drain: Purpose

The purpose of a dry well is to temporarily collect large amounts of water. When there’s heavy rainfall or when you have runoff from your property, the water needs someplace to go. With a dry well, you allow water to collect in one location (or multiple locations if you install multiple dry wells). This keeps the surface clear of flooding. Though the water sits temporarily in a dry well, it slowly percolates into the soil below, clearing it out for the next heavy rainfall event.

A French drain is not designed to hold water but rather to serve as a channel to redirect water to another location. Runoff can seep into your foundation and basement, but a French drain creates a trench that redirects all of that water and moves it away from your property. It doesn’t work slowly like a dry well when distributing the water and instead can handle a continuous flow.

Dry Well vs. French Drain: Installation Location

Since a dry well takes up a lot more space, these are typically installed in open areas like your yard, for instance. A French drain is often installed near your home’s foundation to protect your house from flooding.

Dry Well vs. French Drain: Water Capacity

The exact water capacity of a dry well depends on the type you have installed. However, when compared to a French drain, it’s able to handle a lot more water and hold it for some time. A French drain does not hold water and just serves as a channel for it to pass through. However, it moves along much more quickly than a dry well, which is a much slower, trickling-type flow.

Dry Well vs. French Drain: Water Disposal

A dry well disposes of water slowly and deeply underground. A French drain directs water to a specified location, often in a lower-lying area. Since these work with the use of gravity, they allow the flow of water to remain continuous and deliver it to a safe location like a sewer drain.

French drain, Drain Stones Gravel Floor, Drainage Surface system for Storm Water around Perimeter House with Stainless Steel Grid or Mesh

A French drain is typically set up near your home’s foundation.

©Mariana Serdynska/Shutterstock.com

Dry Well vs. French Drain: Maintenance

A dry well requires regular maintenance to ensure that the bottom section doesn’t get clogged. Any clogs can cause the dry well to overflow, which only exacerbates the issue of flooding. Therefore, keeping it clear allows it to work efficiently. A French drain requires less maintenance, but it is also subject to clogging. Typically, once-a-year maintenance allows your French drain to continue working effectively.

Dry Well vs. French Drain: Flow Control

A dry well is a fantastic option if you experience heavy rain and you need a place to collect water. A French drain, on the other hand, is better for runoff as it’s designed specifically to keep water moving.

Dry Well vs. French Drain: Cost

A dry well is a more labor-intensive project because the hole to fit the basin for the dry well has to be quite large. Usually, a French drain is a more affordable project because it’s not as labor-intensive but there are a lot of factors that play into the cost of either. For example, you have to consider the materials required and how much excavation is going to be required. You also need to consider the storage capacity of a dry well. There are different sizes. A dry well may be more complex both in design and in ensuring compliance with your city and county. There are also differences in the cost of ongoing maintenance.

Dry Well vs. French Drain: Which One Do You Need?

Deciding between a dry well or a French drain is entirely dependent on your specific needs. If you don’t have any storm drains available, a dry well could work out well to distribute water into the ground but keep in mind that dry wells need some kind of drainage system set up so that the water gets directed to them. If your concern is the heavy flow of water, you may find that a French drain is more suited to your needs. For instance, if your yard experiences flooding after rainfall, a French drain could provide that excess water a place to travel through instead of sitting still on your lawn.

The photo featured at the top of this post is © Jasmine Sahin/Shutterstock.com

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About the Author

Angie Menjivar is a writer at A-Z-Animals primarily covering pets, wildlife, and the human spirit. She has 14 years of experience, holds a Bachelor's degree in psychology, and continues her studies into human behavior, working as a copywriter in the mental health space. She resides in North Carolina, where she's fallen in love with thunderstorms and uses them as an excuse to get extra cuddles from her three cats.

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