Back when our land was covered with forests, prairies, and wetlands, rain water fell and either infiltrated into the ground, evaporated off of plants, or ran off into the nearest stream or river. Now, when rain falls on our urban areas, the vast majority of it runs off of hard, or impervious, surfaces like roofs, roads, and parking lots and flows into a storm drain. Underground pipes then send that water into a retention pond, stream, or lake, usually without treating or purifying the water first. That means that whatever the storm water picked up on its journey (oil from driveways, pet waste and fertilizers from backyards, soil particles from new development projects or eroding shorelines, and much more) is ending up in our lakes and streams. Creating a rain garden or growing native plants along your shoreline is a great way you can make a difference and start correcting these problems. Click on the two graphics below for a visual representation of where water goes in a typical suburban area versus one utilizing native plantings.
Benefits to Water Quality
Although rain gardens and shoreline plantings may contain a variety of plants, native species are highly recommended. Native plants, those that are originally from this area, are more beneficial to our environment and are also lower maintenance than species from other parts of the United States or the world. Certain native plant species are also very efficient at absorbing nutrients, and using them in your landscaping can really optimize the benefits the area provides. For example, several rush and bulrush species (which look similar to the reeds you might have seen growing in wetlands) perform well in rain gardens and along shorelines and also do a great job of absorbing nitrogen and phosphate, the main nutrients in lawn fertilizers.
Rain gardens reduce the amount of pollution reaching bodies of water by holding storm water and allowing it to infiltrate into the ground or be absorbed by plants rather than run off. Native species are especially well suited for this purpose – their deep roots create root channels through which water can infiltrate. Additionally, natives that are adapted to growing along shorelines are thirsty and take up water at a rapid pace. Native shoreline plantings slow down storm water runoff, absorbing it and allowing it to infiltrate into the ground or be taken up by plants rather than fill up retention ponds, streams, and reservoirs. This is extremely important as more and more areas are developed. We are losing natural areas that used to provide flood control and need these native shoreline plantings begin to remedy those effects.
Native Plantings and Wildlife
Native plantings like rain gardens and shoreline plantings can also provide unique habitat for native wildlife. The caterpillars of butterflies and moths rely on native plants like milkweed for their diet, adult butterflies feed on nectar from colorful blooms, and songbirds enjoy the seeds provided by native flowers and grasses. Natural shorelines can also benefit fish, frogs, and ducks, all species we like to watch and enjoy.
Canada Geese are becoming a serious problem in our urban areas. They can be very aggressive, especially when they have a nest nearby. Additionally, their droppings contribute nutrients and bacteria like E. coli to the water. Canada Geese tend to avoid native plantings – they are afraid of the taller vegetation because predators could be hiding there. If geese are a problem in your yard or neighborhood, landscaping with native plants could help; some neighborhoods have completely eliminated their goose populations by surrounding their ponds with native plantings.