If you live in an area with heavy rain or abundant groundwater, you may want to build a drainage swale to protect your property. A drainage swale is a channel that follows the slope of your yard and collects water from hard surfaces. It reduces the amount of water runoff in places you want to keep dry.
To minimize the damage from severe weather, some swale systems are built to direct excess runoff to storm drains. This helps ensure the excess water doesn't damage your property or flood your home, yard, or basement.
If you are a novice DIYer, building a drainage swale may not be the best project for you. If you are experienced at difficult outdoor projects, however, this may be something you can tackle on your own. The cost will vary greatly depending on how long of a swale you need to build.
Step 1 - Plan
Like any major project, you'll need to plan out your swale before you start to build it. Next time it rains, look at the way the water is draining naturally. Pay special attention to any areas where water pools. This will help you understand what changes need to be made.
Make sure you're also considering the needs of your garden. If you are planning to add a garden, put it in an area that gets the right amount of water, or where you can easily control the amount it receives.
Draw out the plans for your swale. This will help you have a plan before you start to dig and will help you gather the correct amount of materials. Make sure to order more materials than you actually need to be safe.
Step 2 - Mark the Yard
Use stakes to plan out the path for the swale. Since you have presumably already drawn this out, this should be easy to do. Laying out the stakes will help you ensure that your measurements were correct and that you purchased the right amount of materials.
The stakes should end where you want the water to go, like a rain garden.
Step 3 - Dig
Dig a small ditch in the yard where you will lay the swale. This does not need to be very deep. If you have a small yard, you can do this using a shovel. If you have a big project, you may need to hire a professional, though.
This is the most time-consuming part of this project. Having a friend or family member help you dig is a great idea. You may also want to skip the gym the day you dig—you will be sore.
The ditch should be fairly wide and follow the stakes from the entry point of the water to where it is going.
Use a long 2x4 or several joined together if you can't find one long enough to check that it is pointed downward.
Step 4 - Add Gravel or Tile
Once your ditch is completed, lay gravel at the bottom of the trench. After you add gravel, you can add tile tubing in the trench. This is where the water will actually travel. Finally, fill the rest of the trench with gravel.
Step 6 - Add Grass, Stones, or Plants
Put grass seed or stones on top of the trench to make it look like the rest of your yard. Or, you could use stones to create a design or path at the location of the swale. If you are using plants or grass to create a rain garden, use ones that do well with lots of water.
There you have it. You have built your own swale!
If you notice issues when the next big rain comes, you can adjust it yourself or call in a professional to address the issue. If you want to save time and make the process of building a swale easier, you could also consider having a professional dig the ditch for the swale and do the rest yourself.