If you asked me a year ago what a rain garden was I would not have been able to explain it correctly. I believed one of the many misconceptions, that rain gardens are filled with water. A properly designed rain garden infiltrates the water into the ground within 24 hours. That is their primary purpose, absorb water. The majority of the time, the rain garden is bone dry. They do not breed mosquitoes, again because water does not pool long enough to hatch their eggs. They are low maintenance if you take the time in the spring and fall to tend to them. All these myths keep homeowners from solving their water problems with an aesthetic and effective system.
As a member of the 2016-2017 Master Water Steward class I have learned about rain gardens and other solutions to water problems on residential properties. After graduation this October I will be set loose in my watershed district to help others install these types of best management practices that will help infiltrate water one property at a time. For my own yard, I could not wait until graduation to test my new skills. Spring and all the rain showers that come with it, is here. Last weekend I enlisted the help of my husband to install our first of three rain gardens I have planned for my backyard.
Our house sits on a large lot in Columbia Heights and that has an impervious lot coverage (anything that does not let water into the ground like the house and driveway) well below the maximum limit set by the local zoning code. In spite of this, we still have concerns about the water that gushes out of the gutters next to our 100 year old foundation. We watched too many flashy storms dump gallons of water into our yard last spring. I assessed the numerous options we had for mitigating this issue and landed on an underground catch basin feeding to a small rain garden through an underground pipe.
The first part of this system is the catch basin. It is a small black 12"x12" plastic box with two 3 inch holes on either side. I installed a cap on the unnecessary hole and a 3 inch flexible pipe on the other end. The box was placed in a hole dug directly below the gutter, deep enough to make the top of the box flush with the ground. We dug a trench for the pipe to feed into the rain garden 10 feet away. The large old ash tree (sitting inconveniently close to the project area) roots crossed our path a few times and required a lot of physical labor to cut through. We only sawed about 4 roots for the project, well below the limit of 1/4 of the tree root system removal. Any more than that and you are likely to kill the tree.
The pipe led to a small 3 foot by 3 foot rain garden. Despite the clay soils, the infiltration tests I conducted the weekend before in this area showed our yard was special and allowed water to seep into the soil at a rapid rate. Because of this, our rain garden was dug 12 inches into the ground (the maximum depth you want for any rain garden). After digging the 3 foot by 3 foot by 12 inch deep hole, I sloped the sides of the hole. I added compost and three native plants that were relocated from my front yard. A thick layer of mulch completed the garden.
We filled the soil back over the underground pipe, placed a concrete block at the base of the gutter to funnel the water into the catch basin and took some pictures. With the rainy spring months we did not wait more than a day to see the system at work. The gutter funneled water right into the catch basin which emptied slowly into the rain garden. A more heavy rain fall is needed to truly test the effectiveness of our rain water system, but from the light rain we received, it looks like we fixed our water problem.
The other part of our rain water system completed last weekend is a rain barrel located at the base of the garage. I built a platform to raise it off the ground, assisting gravity to feed water to the cucumber and zucchini plants that will be growing nearby within the next month. The 55 gallon barrel was left in the yard when we bought the house and most of the platform was built using scrap wood, making the project nearly free. With only one outside spigot located in the front yard, the rain water capture will not only keep water from running off my property into the neighbors backyard, but solves my garden watering problems.
As my yard projects demonstrate, fixing the water issues in your own yard contributes to lessening the water runoff problems within your city as well. It can provide a more convenient watering source for gardens or keep water away from your foundation. It can be aesthetic and save money. It pays to fix water problems one yard at a time.