It’s not just a hole in the ground!
A rain garden is a shallow depression created in the ground that will allow water, directed by slope or pipe to enter. The water collected is runoff from a building roof, a driveway, a patio or any other surface that has a high runoff situation. This shallow depression is planted with specific plant material that will thrive in a situation that is sometimes inundated with water, and sometimes allowed to dry out during summer months. The water captured in these rain gardens is slowed, and allowed to percolate back down into the ground. The plant material aids by keeping the pore space in the soil open through root development. Soil is an amazing tool for cleaning water. Just think of a typical leaching field for your septic system. And, once the water is cleaned, it will continue on to recharge our water table.
A rain garden is just that. It is a garden that holds rain water. And we approach the installation process much the same way we approach a typical garden. We allow for a proper organic soil layer in which the plants are planted, then spread a layer of shredded bark mulch to protect the soil and reduce any weed growth. Over time, the microbiological activity that is found in the top organic layer is capable of rendering some pollutants inert from the captured rain runoff. The plants in a rain garden will also capture and bind pollutants in the water.
By building a rain garden on your property, not only will you be doing your part to help clean the water of pollutants, and recharge our water table, but also help in reducing the flooding and erosion potential in your area. To properly construct a rain garden you need to know the soil type, the amount of water you will be directing towards the rain garden and the slope of the area where the rain garden will be situated. These are not wetlands so the choice of plants is essential for an effective rain garden. Check out “Rain Gardens” in the “Digging Deeper” section of this site.