Rain gardens are a new way of gardening whilst saving the environment around us. Many times the rain water just flows into storm drains. You may think that this is the best way – but so far it’s been the only way we know. This actually causes a problem as the rain water causes erosion of the soil, water pollution as the storm drains collect dirt along the way, flooding when the surface water level becomes high and it does not dissipate into the ground because of concrete paving. The groundwater gets diminished and this does not help for the future.
What is a Rain Garden?
A Rain Garden is a depression or a hole that allows the rain water to flow off from impervious surfaces like roofs, walkways, driveways, compacted lawn areas and parking lots so that it can be given the opportunity to be absorbed. Storm water drains send the water straight to the sea depriving the soil and groundwater to get replenished. A rain garden should be designed for certain types of soils and climates.
The purpose of having a rain garden is to improve the water quality in water bodies nearby and also to allow the rain water to be available for plants to grow in the form of ground water. Studies have shown that rain gardens can reduce the amount of pollution reached nearby water bodies like creeks and streams by up to 30%.
If you’re thinking of building a rain garden in your area or home, you should think about planting native or adapted plants as they would be best equipped to deal with the climate, soil and water conditions of the area you live in. They have better tolerance for various conditions that could be native to your area and could have deep and variable root systems for drought tolerance and water infiltration. Using native plants for your rain garden also helps overall sustainability for local ecological communities.
Certain vegetation like shrubs, ferns, small trees, wildflowers and rushes absorb the excess water into the rain garden. In the natural process of transpiration the plants in your rain garden can help return the moisture and the water vapor into the atmosphere. You should plan to make your whole garden into a rain garden and carefully select the plants and trees that are part of it. Think of it as a rain garden as a whole and the smaller components like the various plants acting like mini-rain gardens on their own scale.
Advantages of a Rain Garden
In many developed areas, the ground is always leveled up and any holes are always filled to avoid mishaps and casualties. Storm drains are built to channel the rain water away from built up location but this can serve to overflow the sewage systems and also poison, flood or erode the waterways receiving the run off. As redirected storm water is normally warmer than the ground water, a few aquatic ecosystems get disturbed by the run off. This is because pollutants can wash off compacted surfaces into the run off. Creating a rain garden will ensure that the rain is absorbed back into the ground, eliminating any erosion or poisoning of the water.
Rain gardens reduce energy consumption, capture the initial flow of storm water and also reduce the accumulated toxins that can flow directly into the natural waterways via ground filtration. Rain gardens at times negate the need for irrigation as they allow the water to infiltrate the ground after a period of a day to two days. Therefore, this helps in reducing the load that the storm drains face during a heavy downpour.