Morris Arboretum’s Renews Sustainable Parking Lot — A Model after 25 Years of Service
The Morris Arboretum’s permeable parking lot is being renewed and rededicated after 25 years of service. The original parking lot used innovative and, for its time, unique construction techniques to create an asphalt surface that permitted water to sink right through the pavement and filter into the groundwater below. The first of its kind, this innovative parking lot has won awards for engineering and design, been featured in national publications and regional educational videos, and is frequently visited by school students, university classes, engineers, architects and landscape architects from around the world. Visitors are interested in its ability to absorb stormwater without creating runoff, and its longevity – its permeability meant that water did not pool in cracks and crevices to create potholes during periods of freezing weather.
Over the last 25 years, the Arboretum estimates that the parking lot has eliminated troublesome runoff of about 31,863,304 gallons of rain and snow – equivalent to a lifetime supply of drinking water for more than 1,000 of the Arboretum’s neighbors downstream.
The parking lot, installed in 1989, was Morris Arboretum’s first public parking lot, and was designed with neighborhood input to accommodate the growing number of visitors to the Arboretum. Key to the planning was the desire to respect the historic 19th century landscape of the nearby Gates House, and to provide a permanent exhibit of exceptional ecological urban planting. The groundbreaking engineering enables storm water to filter down through the parking lot and recharge the water table below, while providing a high-quality visitor experience.
In December, Morris Arboretum peeled up portions of the porous pavement which had eroded over time to investigate the performance of the stone recharge bed and filter fabric. The examination of sediment accumulation and materials durability determined that the subsurface is still functional. Since this lot is the earliest and longest-operating permeable pavement parking lot, it offers a unique advantage to add to our knowledge of best design and management practices.
When work begins this Spring, the permeable parking bays will be cut and peeled back to mitigate contamination by the weathered asphalt, the cobble edgings will be reset, and a new permeable surface will be installed. “It is exciting to think that a demonstration parking lot installed 25 years ago still serves as a model for best practices,” says Bob Gutowski, Director of Public Programs at Morris Arboretum.
The garden will remain open during the parking lot renewal. Alternative parking will be available at a remote location, with free shuttle service maintaining easy access to the exhibit landscape. Visit http://www.business-services.upenn.edu/arboretum/index.shtml