Rain Gardens Take Root: Residents Create Rain Gardens to Improve Their Communities
Mar 19, 2018 09:16PM ● Published by Melanie Heisinger
Bloomsburg rain garden construction
Gallery: Rain Gardens [10 Images] Click any image to expand.
By Erica L. ShamesWith every rain storm, pollutants are washed into waterways from rooftops, roadways, driveways, parking lots and sidewalks. This influx of rain water runoff increases the severity of flooding events and adds undesirable pollutants to rivers and streams.
We’ve seen the devastating implications of floodwater from Texas and California to the other side of the world. The question becomes, what can we do to stem the occurrence of these events?
Rain gardens offer a way to capture rain water and allow it to permeate through the soil to reduce erosion and flooding. They slow, retain and even filter rain water runoff using landscapes created with this special purpose in mind.
Through the use of intentional design and plant selection, rain gardens are able to halt the flow of runoff, thereby allowing the water to seep back into the ground while removing harmful pollutants like nitrogen and phosphorus.
A sensible solutionThe Borough of State College was encouraged to create rain gardens on Barnard Street in 2009 and Allen Street in 2011 to reduce urban runoff and reduce impervious area within the borough. “A third incentive to pursue rain gardens was the discovery that our local high-quality stream, Spring Creek, was being impaired by urban runoff,” explained Alan W. Sam, the borough’s environmental coordinator and arborist.
The final rain garden drawings used to create the gardens were based off work done by Penn State landscape architecture students, who designed a meandering path for water to run through the rain garden and suggested a list of plantings. The gardens also incorporated features with special intentions.
“Check” dams—small barriers constructed of rock placed across a constructed swale or drainage ditch—help slow runoff and allow for water infiltration into the soil. Yard inlet drains enable excess water to run into the storm sewer. A second storm drain was added to the entrance of the west side of the Allen Street rain garden to prevent flooding from the high volume of runoff it receives.
Putting it all togetherThe rain gardens were constructed with a layer of rock, topsoil and compost (totaling 2.5 feet deep) to enhance the infiltration potential. Rain garden plantings must be tolerant of wet and dry conditions that change rapidly in an urban environment. They allow water to infiltrate into the soil, provide a substrate for pollutants to be broken down and allow for the evapotranspiration of rainfall— the process by which water is transferred from the land to the atmosphere by evaporation from the soil.
Education panels were installed at each rain garden, focusing on the role rain gardens can play in stormwater management while helping to protect the Spring Creek Watershed. The panel on the west garden has a children’s section that dovetails with its location in front of the Growing Tree, a children’s toy store.
The results have been encouraging. “There is increased awareness and recognition that stormwater or urban runoff can be a serious environmental issue,” said Sam. “The gardens have increased interest on the part of Penn State, developers and homeowners as a way to control runoff.”
As a result, the borough has made a commitment to look at opportunities for rain gardens with every road construction project. This spring, a rain garden installation is planned for the intersection of Pugh Street and Easterly Parkway. Another larger rain garden is being designed for Easterly Parkway between Pugh Street and William Street.
“This is an environmentally responsible way to control and reduce stormwater runoff,” emphasized Sam. “Rain gardens may reduce or delay costly infrastructure improvements in the future. A final reason to include rain gardens? They look good.”
A path to followIn keeping with its vision to protect water quality of the Susquehanna River, the Susquehanna Greenway Partnership created three rain gardens. Funds were secured from the Foundation for Pennsylvania Watersheds, DCNR and private sources.
“Rain gardens allow water to be absorbed into the ground within a day or two, therein lessening the flow of water and pollutants into our rivers,” says Trish Carothers, Susquehanna Greenway Partnership River Town program coordinator.
The Columbia County rain garden was installed in conjunction with Columbia County Conservation District watershed specialist Nancy Corbin, P.E. and Penn State Master Gardeners of Columbia County as part of a new parking lot project at Kocher Park to manage stormwater runoff.
A new river access project in Jersey Shore, a SGP River Town, required additional parking for vehicles and boat trailers, adding impervious surface and, as a result, runoff. A rain garden installation was envisioned to capture and filter the run-off before it reaches ground water and the river.
Trinity United Methodist Church in Danville reached out to the SGP in looking for remedies to curb the runoff from their unusually large parking lot. “They were looking for help to capture, slow down and infiltrate some of the water,” said Carothers. “A well-designed rain garden is visually appealing, can provide habitat for pollinators and, because the water does not remain for long periods of time, mosquitos are unable to breed in them.”
Eyeing the new projects as opportunities for learning and “greening,” the River Town Team and Master Gardeners created two educational signs for the rain gardens and buffer. The signs tell the story of this green infrastructure and help visitors to the site understand the many benefits of the projects including clean water, community beautification and habitat creation.
“We noticed a lot of common goals between the Master Gardener program and what the Jersey Shore River Town team is looking to accomplish for a cleaner, greener, more connected Jersey Shore,” said Sid Furst, SGP Board Member and recent graduate of the Master Gardener program.
In the future, as more communities charge a fee for stormwater management, homeowners may look to rain gardens as a tool in harnessing drainage, noted Carothers. “Property owners that use rain barrels and rain gardens to manage their own stormwater may qualify for [financial] credit,” noted Carothers.
Local Master Gardeners and conservation districts are good sources for more information on rain gardens. And you can visit SusquehannaLife.com/WebExtras to learn how to create a rain barrel and rain garden.