If you are having problems with drainage on your driveway, installing a drainage channel (also called a channel drain) can help.
A channel drain collects runoff from the driveway and carries it through an underground system to a more appropriate location. You can drain the water in another part of the yard, into a municipal drain or harvest it in a tank.
Installing a channel drain on your driveway is easy enough that you can do it yourself. Here’s how to do it.
What You'll Learn Today
- What Is A Channel Drain And How Does It Work?
- Where To Install A Channel Drain?
- How To Install A Channel Drain: A Step-by-Step Guide
- Can You Put A Channel Drain In A Gravel Driveway
What Is A Channel Drain And How Does It Work?
A channel drain is one of the most effective methods for draining a driveway. Paver, concrete and asphalt driveways create a lot of runoff since water doesn’t soak easily through these materials.
So instead, water flows over the driveway surface. This causes several problems depending on where that water is headed.
If it flows into the yard, it’s usually fine though it can sometimes lead to soggy or flooded areas in the yard. If the water settles near your house, it could cause moisture problems in the foundation and walls.
If the driveway slopes towards the garage, you could have rainwater flowing right under the door and into your garage.
If the driveway slopes the other way, you’ll have water flowing into the street. This could get you fined in some cities.
A channel drain solves all these runoff problems. The drain is usually installed across the width of the driveway. Stormwater flows into the channel through a grate on top.
The channel is connected to an underground pipe that carries the water wherever you want.
A channel drain consists of two main parts: the channel itself where water flows through (usually made from plastic) and a grate (plastic, composite or metal) that’s strong enough for vehicles to drive over.
Where To Install A Channel Drain?
It’s really important that you choose the right location to install a channel drain. Keep in mind that the goal here is to capture all the runoff coming off the driveway.
So you need to install the drain in a location where it can catch most of that runoff. Exactly where that is depends on the gradient and profile of your driveway.
Locate the lowest area of the driveway where all the runoff flows towards. Depending on your driveway, this can be at the garage end, the end that leads to the road, or somewhere in the middle.
While normally a channel drain is installed across the width of a driveway, there are situations where you might have to install it along the side of the driveway.
If your driveway is curved, you may find water flowing off the driveway along one of the bends.
You can also install channel drains all along the length of the driveway on both sides to catch water along the entire line.
How To Install A Channel Drain: A Step-by-Step Guide
Here’s a general step-by-step guide on how to install a channel drain across your driveway.
1. Select The Right Location
The first step is to determine where the channel drain will be. I’ve already covered this in detail above.
Choosing a location first makes it easy to figure out the size and quantity of the materials that you’ll need to build the channel.
In addition to the location of the channel, decide where the underground pipe will run and where it’ll dump the stormwater. Take advantage of your yard’s slope when planning where the pipe will pass. This will ensure water flows easily by gravity.
Tip: Make sure you know the location of underground utilities before planning where to dig a trench for the piping. If you are in the US, call 811 to have someone come and mark the location of utilities.
2. Have Tools and Materials Ready
Next, draw up a list of all the tools and materials that you’ll need. Don’t worry if you don’t have certain tools; you can always rent for a few hours or a day.
The most challenging part is cutting out a section of the driveway where the trench will be. You can use a circular saw to cut through the concrete, pavers or asphalt.
To dig a trench across the driveway and yard, you can use a shovel. There are even special trenching shovels.
You’ll also need tools to mix and spread concrete. You may need a wheelbarrow, bucket, trowel and other basic tools.
As for the materials, you’ll need the drain channel kit, concrete, and drainage pipes. Note that the channel kit will come in sections that you need to join.
Since you already know where the channel drain and trenches will go, it should be easy to know the length of piping and channels that you need.
Tip: The width of the channel is important. The wider it is, the higher the volume of water it can carry. If your driveway gets a lot of runoff, get a wide enough channel to ensure it can handle all that water.
3. Rip Out A Linear Section Of The Driveway
Now it’s time to get to work. You’ll need to rip out the section of the driveway where the drain channel will be.
When cutting out a section of the driveway, be sure to account for the width of the channel drain plus about 4 inches on either side of the channel that you’ll fill with concrete.
Tip: A circular saw with a diamond blade is the best tool for cutting through concrete, pavers or asphalt.
The best technique for ripping out the driveway is to cut two lines along the width of the driveway. The distance between the two lines will be the width of your trench.
Then cut several smaller lines along the linear section that you’ve just cut. This creates smaller sections of pavement or concrete that you can easily remove with a crowbar.
4. Dig A Trench Along The Water Travel Path
Once you remove all the surface material, you can now dig a trench where the channel will sit.
The channel should sit about 2mm below the surface of the driveway to ensure water flows into it. So the depth of the trench that you dig should account for this plus the depth of the channel itself.
It’s also a smart idea to have a bed of sand under the channel to stabilize it. Add about an inch to the trench depth for the sand.
When digging the trench, make sure you create a gentle fall towards where the water will drain.
Since you are digging a trench for the channel drain, you might as well dig the rest of the trench where the drainage pipe will go. Remember to maintain a slope/fall towards where the pipes will drain.
5. Install The Channel and Grate
Start by adding a bed of sand to the bottom of the trench.
By the way, another advantage of adding sand to the bottom of the trench is that it lets you easily adjust the slope of the channel drain by removing or adding sand underneath.
Lay the channel section on the sand and link them together. Use a level to make sure the trench slopes towards the drain.
Finish by backfilling the sides of the channel drain with concrete. Use a trowel to finish the concrete smoothly.
Tip: One brilliant method I’ve seen contractors use is covering the grate with packing tape. You can then add concrete to the sides of the channel without worrying it’ll block the grate. Before the concrete hardens, peel off the tape.
6. Install The Piping
If you’ve already dug the trench for the drainage pipes, then all that’s left is connecting the drainage channel to the pipes. Channel drains have several outlets at the sides and bottom for connecting to pipes.
Backfill the trenches to cover the piping and you are done.
7. Test The Drainage
The best test is rain. But if it’s the dry season, you can pour water into the channel drain and observe how it flows.
Check the other end of the pipe to make sure water is draining out properly. If it’s not, you may have a problem with the slope of the channel or drainage pipes.
Before you pat yourself for a job well done, wait until it rains to really see how the drainage channel handles large volumes of water.
Make sure runoff flows easily into the channel and that the channel and pipes are able to quickly carry away the stormwater.
If you need more help with the project, here’s a detailed video providing a step by step guide.
Can You Put A Channel Drain In A Gravel Driveway
You can certainly install a channel drain on a gravel driveway, though there’s a risk of small bits of gravel washing into it. Put pavers, or a wide band of concrete on both sides of the channel to reduce clogging.
But what works best for a gravel driveway is a French drain. This is a trench with perforated piping and permeable fabric. It collects water from the surrounding area and drains it elsewhere.
In some cases, you may not even need any extra drainage for a gravel driveway. Since gravel is highly permeable, water absorbs easily into the ground. Just make sure you have proper edging to keep water from washing away the gravel.
It’s only in areas with heavy runoff (e.g. on steeply sloped gravel driveways) that you may need additional drainage like a French drain or a swale.