What is a rain garden?
A rain garden is a designed planting of deep-rooted native plants in a shallow depression. Its purpose is to collect rainfall runoff from hard surfaces, such as a driveway or house roof, and return this water to the ground while filtering out pollutants.
Rain Gardens at North Park
You will find three rain gardens at North Park. They are situated to capture rainfall runoff from the parking lot and the mowed lawn area in the park. Runoff water slowly percolates through the plant roots and soil in the rain gardens to recharge the ground water with clean water. Our rain gardens help maintain good water quality in the adjacent Sacony Creek by preventing this runoff water from flowing directly into the creek and by filtering out pollutants, like leaked engine oil from the parking lot or excess nutrients from the mowed lawn. Kutztown residents depend on good quality water in the Sacony Creek because the borough’s shallow drinking water wells are located in the creek’s watershed and share the same surface water as the creek.
Specifics of Rain Gardens
Rain gardens are typically small and suitable for catching runoff water from driveways, homes, residential lawns, or a single downspout off of a larger building. They are an ideal solution for limiting impacts of runoff in residential landscapes. Even at home water runoff can be considerable – an average-sized house can shed 14,000 gallons of water in a one inch rain storm! The planting depression of a rain garden is dug out and, if local soil drains poorly, must be filled with an appropriate soil mix (organic matter and topsoil with a lower layer of gravel) that provides good drainage. Rain gardens do not hold standing water for long and will not breed mosquitos. Appropriate plants are added by planting seeds or mature plants. Rain gardens increase the beauty of a home landscape as well as improve ground water recharge.
Rain Garden Plants
Plants native to the local area are used in rain gardens. These plants are adapted to deal with local conditions and require no special care once established. Native plant species are chosen that can tolerate periodic wet conditions following storms and drier times between storms. A mix of grasses, wildflowers and shrubs are usually found in a good, biologically diverse rain garden. At North Park, only plant species native to Pennsylvania were used. Our rain gardens were planted with the seeds of 6 species of grasses and 18 species of wildflowers. Three species of shrubs were added as mature plants. These deep-rooted native plants help to filter contaminants from the runoff, reduce the impacts of runoff water, and support wildlife.
Wildlife Benefits
The native plants in a rain garden produce beautiful flowers and support a diverse community of wildlife. The blooms of native flowers provide a nectar source for bees, butterflies, and hummingbirds. More importantly, native plants are the food source for many species of insects. For example, monarch butterflies gather nectar from many types of flowers but their caterpillars can only be raised on native milkweed plants. Loss of milkweed habitat has been implicated in the decline of monarch butterflies. Birds and other animals also rely on native plants for food because they eat the insects raised on the plants as well as the seeds and berries they produce. Plants that are not native to the local area produce far fewer insects than native plants. Overall, native plants are critical to wildlife because they support the base of the food chain.
For more information about rain gardens and how to install one on your own property, please visit these links.
https://www.epa.gov/soakuptherain/soak-rain-rain-gardens
http://extension.psu.edu/plants/gardening/eco-friendly/rain-gardens
http://www.phillywatersheds.org/whats_in_it_for_you/residents/rain-gardens
http://www.raingardennetwork.com/
Acknowledgments
The North Park education sign project was funded by an education grant from the Pennsylvania Department of Environmental Protection to Todd Underwood and Christopher Sacchi of Kutztown University. Assistance for this project was also provided by the Public Works Department and Environmental Advisory Commission of the Borough of Kutztown and Kutztown University. We thank Michael Tripoli for his original rain garden artwork. Robyn Underwood allowed us to use her photograph and one photograph was obtained through the public domain. We also thank Shireen DeNault for design advice.
