Award-Winning Next Generation Rain Garden
Garden Magic has set the new standard for design, installation, and maintenance of rain gardens at St. Peter’s Episcopal Church in Mountain Lakes, New Jersey.
Garden Magic and its St. Peter’s “Next Generation Rain Garden” project are the winners of the 2019 Governor’s Environmental Excellence Award in the Water Resources category (press release).
While there are many hundreds of rain gardens installed throughout New Jersey, St. Peter’s rain garden is unique. Garden Magic included all the basic components of a standard rain garden (e.g., stormwater infiltration basin; native plants) in its design, plus many advanced concepts to overcome site complexities and meet watershed objectives, while improving native plant viability, habitat diversity, and overall attractiveness. It is now the defining example of a state-of-the-art rain garden, incorporating best stormwater practices and gardening methods, setting the new standard for future installations.
Managing Excessive Stormwater
St. Peter’s rain garden serves as a landscaping solution to help manage the negative impacts of stormwater runoff – flooding, erosion, and contamination of water resources. Prior to installing this rain garden, stormwater from the church roof, rectory roof, rectory driveway, and from the hill behind the parish hall all ran down the front bank and steps. During pouring rains, a torrential amount of water washed down toward Boulevard, carrying with it eroded sediment and various pollutants.
State-of-the-Art Rain Garden
St. Peter’s Church rain garden consists of a rock-lined berm, a shallow stormwater basin, and a new garden bed planted with native shrubs and perennials. The shallow basin interrupts the rapid flow of stormwater runoff as it washes down the hill. By catching and holding rainwater, onsite bank erosion and downstream flooding are reduced. Water caught in the basin slowly infiltrates into the soil (over several hours), which recharges groundwater aquifers while filtering out pollutants and keeping them out of streams and lakes. The native plants in the rain garden assist by keeping the soil porous, soaking up some water, and removing some chemical impurities.
Using Native Plants
Native perennials and shrubs are planted in the basin to improve soil permeability and to absorb additional water through their root systems. The specific plants have been selected to match the sunlight, soil, and water conditions found in the rain garden. Water and drainage are particularly challenging, because the plants located at the bottom of the basin must be able to withstand both being submerged under several inches of water and periods of drought.
Because native plants have adapted to local climate, soil, and hydrologic conditions, they have proven to perform better in rain gardens than highly cultivated, garden plants. Native plants usually possess some natural defenses to pests and diseases, so they tend to be more sustainable and require less care and garden chemicals.
Created to become a balanced, native ecosystem, St. Peter’s rain garden supports a healthy pollinator population.
Next Generation Special Features
A) Site was selected for maximum infiltration and erosion control
B) Topography and natural contours were used to define the garden boundaries
C) Main berm is lined with stones to blend into the landscape and make it compatible with the church and historic walls
D) The basin includes two overflows to serve as outlets during extreme storms
E) First overflow goes into a drywell for extra retention capacity and infiltration
F) Plants have been positioned for maximum visual impact and habitat capacity
G) Basin was dug by hand to limit compaction and to preserve topsoil, so it could be reused for garden planting
H) Use of drainage rocks was minimized for easier maintenance
