Adam Osborn of Americorps takes part in the rain garden project in a parking lot at Thompson Park, Jamesburg, on April 27. The garden is a planted, shallow depression that is designed to capture rainwater runoff. More photos at gmnews.com. JEFF GRANIT staff JAMESBURG — A grassy island in a parking lot at Thompson Park has been transformed into a rain garden, complete with coneflowers, black-eyed Susans, Joe Pye weed, and other assorted native plants.
The vegetation is designed to treat polluted storm-water runoff before it flows into the adjacent Manalapan Lake.
On April 27, Middlesex County Freeholders Carol Barrett, Stephen J. “Pete” Dalina and Ronald Rios welcomed a group of more than 35 volunteers from a Rutgers Cooperative Extension Rain Garden Certification Workshop, who installed the approximately 1,300-square-foot rain garden,
“It is critical that we do everything possible to address pollution that affects our lakes and streams,” said Barrett, who chairs the county’s Engineering and Planning Committee. “Treating parking lot runoff with a rain garden before it enters the lake is an effective and low-cost approach.”
Volunteers from a Rutgers Cooperative Extension Rain Garden Certification Workshop work on the rain garden in the parking lot near Manalapan Lake. JEFF GRANIT staff A rain garden is a planted, shallow depression that is designed to capture rainwater runoff from impervious surfaces like driveways, rooftops, walkways and compacted lawn areas. The runoff can carry salt, sand, pet waste, pesticides, fertilizers, leaves and grass clippings, oil, litter and other pollutants into nearby waterways.
Once in the garden, the polluted water is taken up by the plants, infiltrates into the ground or evaporates as water vapor. Officials expect the rain garden at Thompson Park to intercept polluted runoff from the adjacent parking lot before it reaches Manalapan Lake.
“Thompson Park is the perfect location for this demonstration project,” said Dalina, chairman of the Parks and Recreation Committee. “We are making this incredible park even more beautiful by planting such colorful blooms while at the same time improving the water quality of our lake and stream system.”
The rain garden demonstration project is the first component of the Manalapan Brook Watershed Restoration and Protection Plan, scheduled to be completed later this year. The Middlesex County Department of Planning has led the effort, which is funded through a federal Clean Water Act grant. Other partners in the effort include the New Jersey Water Supply Authority, county Department of Parks and Recreation, nine municipalities in Middlesex and Monmouth counties, the Freehold Soil Conservation District and others.
The plan focuses on rehabilitating the watershed, which stretches from Millstone Township in Monmouth County to DeVoe Lake in Spotswood, where the Manalapan Brook meets up with the Matchaponix Brook and forms the South River.
The plan was developed to recommend measures necessary to address high concentrations of total suspended solids that affect water quality in the Manalapan Brook and its tributaries, and eventually end up deposited in Manalapan Lake, which is in Thompson Park. The suspended solids are made up of small particles that are washed into the stream with storm-water runoff, and soil that is flushed from stream banks during storms.