Bioretention basins are becoming more and more popular these days. Some local governments are requiring them in places where new parking lots or roads are being built. The main purpose of these bioretention basins is to filter out the pollutants in stormwater runoff, with the end goal being to keep our waterways cleaner and healthier.
The basins are setup so that most of the stormwater from a given area (i.e. parking lot) is diverted into the basin. As the water reaches the basin and percolates downward, the plants and soil filter out the various pollutants that are present in the water.
Some bioretention basins are much more complex than others, requiring engineered soils, drainpipes, pond liners, and a diverse selection of native plants. However, any homeowner can create a simpler bioretention basin, often referred to as a raingarden. A raingarden is basically a landscaped area that is in a low spot where stormwater will collect.
There are many benefits in creating a bioretention basin. They are much more attractive than a conventional stormwater management system. They also greatly benefit the environment, filtering stormwater runoff as mentioned above and creating habitats for local wildlife.