By Brian Clark Howard
Homeowners and businesses can stem the tide of polluted runoff threatening our waterways by setting up a simple "rain garden," which is beautiful as well as beneficial.
The concept of a rain garden, which mimics natural systems, was crystallized in Maryland in the 1990s. The idea is to create a depression filled with plants that collects the rainwater that runs off a building and its landscape. The plants — such as sedges, rushes, ferns, wildflowers, shrubs, trees and so on — absorb the water and release it slowly. This reduces the surge of water running off the landscape, which picks up fertilizers, pesticides, motor oil and other contaminants and carries them into waterways.
Rain gardens reduce the risk of flash floods, and they help stabilize the flow that enters waterways, both in terms of volume and temperature. That leads to healthier streams and rivers. Plus, the plants naturally filter the water, neutralizing some of the toxins that are present. They also provide valuable wildlife habitat.
No two rain gardens are exactly the same. They can be large and interconnected, with different levels and features, or very small and simple. Normally, they are placed in natural low spots, near where gutters drain. Ideally, they are populated with plants that are native to the local area. Sometimes they have swales to maximize their ability to hold water. Get tips on starting one here.
