Controlling Exterior Water With a Rain Garden
As I wrote in a recent article, controlling exterior water is the starting point for solving and preventing moisture problems in a house. In that article, I included a video showing how the water drains in my yard and what we did about it last year. Now, we’ve taken what I hope is the final step in keeping water away from our foundation. And we ended up with a beautiful rain garden as well.
Keeping backyard water away from the basement
The photo below shows what part of our the backyard and the area just outside our basement looked like last year during our basement remodel. The whole backyard drained over to this area. The lowest spot in the whole yard is just outside the basement.
So we did two things to limit the amount of water in this lowest spot. We had the backyard regraded so that it drains straight to the side instead of moving toward the front, too. And we had a curb put in at the basement door to prevent water from coming under the door. If you’re not able to picture that, watch the video I mentioned above.
The missing piece
That work, however, didn’t solve all our problems. But it did rechannel most of the water to other areas. Now I’m pretty sure the only water that reaches that part of the yard is the water that falls there.
Clearly, though, we still had a problem. The lead photo of this article shows standing water just outside our basement door after a storm one day last month. I don’t want to see any standing water there.
Fortunately, that storm happened three days after the solution to my problem appeared on the scene. The speaker at the Atlanta BS & Beer meeting in June (where I found out about the mosquito bucket of death) was Tres Crow of Greenbox Homes. (That’s him in the second photo below.) I had him come out to give us a quote to do some landscaping and help solve this problem.
He came up with a plan to create a rain garden, which they executed last week. But it wasn’t just filling the whole area with a rain garden. That by itself wouldn’t do a good job of controlling exterior water. In fact, it could make it even worse by keeping water near the foundation.
No, the actual rain garden is a couple of meters away from the house, where that vertical wheelbarrow is above. And the space between contains underground terraces, as you can see there.
Terraces, rocks, soil, and plants
The next step was filling those terraced areas with rocks and soil. The idea here is to create enough storage capacity that all the water that falls on that area penetrates down into the rock-filled terraces. There’s plenty of capacity there.
The photos below show what it looks like now that all the rocks, soil, plants, and pavers are in place.
That area has been a mudpit this year because of all the rain we’ve gotten. Now that we’ve turned our basement into a really nice space, we have an entrance to match. And we got to take advantage of it just a few days ago. We had a sofa delivered, and the two workers got all the way to the basement door with having to walk through mud.
Our new landscaping now gives us a rain garden that should help with controlling exterior water. The plants are mostly native and non-invasive (Tres’s specialty). And there’s plenty of underground storage capacity. Now I can’t wait for the next big rain to test it out.
Afterword: Tres is great with sustainable landscaping, and I recommend his company, Greenbox Homes, if you’re looking to improve your yard in the Atlanta area. And in case you’re wondering, no, I’m not getting any discounts for saying this.
Allison A. Bailes III, PhD is a speaker, writer, building science consultant, and the founder of Energy Vanguard in Decatur, Georgia. He has a doctorate in physics and is the author of a bestselling book on building science. He also writes the Energy Vanguard Blog. For more updates, you can follow Allison on LinkedIn and subscribe to Energy Vanguard’s weekly newsletter and YouTube channel.
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It’s refreshing when people like Tres think with the elements of their trade, in this case soil, water, rocks, plants. The widely present red clay here in Atlanta area soil mix allows for this underground terracing. The only concern I would have for the longevity of this project would be clay infiltration into the rain garden level. I presume that Tres may have opted not to use any synthetic filter fabric because of concerns related to microplastics in the environment?
Paul: I suppose clay infiltration is a possibility, but I think it would take a long time to have a significant effect on the storage capacity. Yes, you’re right about Tres avoiding microplastics. He didn’t use any kind of soil cover in this area. In the places where he did, he used cardboard.
Allison, filter fabric would be underground, enveloping the rock mix in the rain garden area.
My property in Seattle WA is only 40 feet wide and about 80 feet long., with a long house setting on it. All of my roof/downspout water drains into my side sewer line and then to the main in the street. Our city has offered to help pay for rain gardens, but I don’t think it would work for me due to the small property area and the high volume of water. One time I had to bail literally hundreds of gallons of water over the course of about 10 hours into the street (to prevent flooding my basement and my neighbors’) when my gutters were iced over and it began raining and water started pouring from the gutters into my front flower beds. I set several 32-gallon cans below them to catch the water. I can’t imagine my small back yard or front yard being able to handle all of that. I’ve even seen water pooled in my back yard at times, even though no roof water is going into it. Carefully evaluate your situation before trying a rain garden.
Debbie: Thanks for your comment. I should have included a section on cases where a rain garden doesn’t make sense or may even be a bad idea. Rather than adding it to this article, I’ll probably do a followup piece on that.
Enjoying your articles that branch out from HVAC into other home improvements. Thought surely this article would culminate into a mosquito bucket built into the rain garden!
Debbie: I’ve got two of my orange mosquito buckets over there, and I’ve been thinking of ways to do just what you suggest.
Speaking of killing mosquitos: I remember you posting about a complicated way to attract and kill them. I instead have 2 birdbaths in my back yard, which are actually shallow bottom trays that I repurposed from some planters that we no longer use. Many birds use them every day. I place them on top of 32 gallon flat-top plastic trash cans that I use for storage of tarps, etc., underneath some bushes in my back yard. I change the water every day, and I suspect that these trays act like kind of a bait-and-switch. Mosquitos think it’s a good place to lay eggs. but then I assume that they don’t hatch or mature since the water is dumped onto the ground at least once a day. I sometimes see a mosquito flying around when I dump them. I also rinse them well with a hose in the front yard when it looks as if algae are growing in them. I fill them with water from a well-rinsed milk jug instead of using a hose.