Stuart Weitzman School of Design
102 Meyerson Hall
210 South 34th Street
Philadelphia, PA 19104
“A central Delaware riverfront greenway will protect natural, cultural and scenic resources, provide recreational benefits, enhance natural beauty and quality of life in neighborhoods and communities, and stimulate economic development opportunities.”
Michael DiBerardinis, secretary, Pennsylvania Department of Conservation and Natural Resources
In many cities, land at the river’s edge is reserved for birds, plants and people rather than for buildings. Whether at the Jersey shore or along the Delaware River, there are many reasons for requiring that buildings be set back from rivers. Space along the central Delaware River’s edge can be preserved as a public recreational space, offering trails and other activities that open up the riverfront to Philadelphians. When the space at the water’s edge is filled with trees and plants, it becomes a greenway. A greenway improves river water quality, creates new habitat and generally contributes to a healthy river in which fish and other wildlife can thrive (64). A greenway attracts investment and raises the value of surrounding properties by 10 to 20 percent (65). In addition, a greenway can manage the immediate area’s stormwater and limit the negative economic effects of river flooding, which some predict will increase in coming decades due to climate change.
An economic study estimates that the development and remediation of a greenway on the northern Delaware will create between $828 million and $1.4 billion in private capital investment (66).
Cities such as New York City limit any construction or pavement within 100 feet of a river, and other cities and states have enforced much more extensive greenways (67). The width of a greenway determines its effectiveness in filtering pollutants out of the river and absorbing stormwater. The width of 100 feet is recommended by the Environmental Protection Agency and respected scientists (68). The zoning for Philadelphia’s Waterfront Redevelopment District currently calls for only a 50-foot setback and does not require that the setback be planted with shrubs and grasses, which filter pollutants and improve water quality.
Joining our peer cities in establishing a 100-foot greenway is important for the health of Philadelphia’s central Delaware. The popular Schuylkill River Banks trail is wonderful, but with only 12 feet of available land at various points along the river, the trail could not allow for a greenway to create new habitat or reduce river pollution. The Schuylkill River, however, does have the protection of Fairmount Park, which was established in the 1850’s to protect the city’s water supply by creating a natural border around the river. Philadelphia has not created any similar green space to protect the Delaware River. While the city’s optional Waterfront Redevelopment District guidelines call for a 50-foot greenway, which will contribute to the health of the river, Sarah Thorp, executive director of the Delaware River City Corporation, says that this narrow width significantly limits options for creating habitat or filtering pollution and at times is too narrow a setting for a recreational trail.
A greenway setback of 100 feet or not more than 20 percent of any property should be enforced through Philadelphia’s zoning code. To preserve a greenway at the water’s edge, an immediate zoning overlay is needed that will limit development within 100 feet of the water’s edge. The ordinance should anticipate that some properties will not be able to reserve 100 feet across their entire parcel and should allow greenway averaging that permits the greenway to become narrower at some points along the river, as long as the average width of the greenway meets the minimum requirement. For some properties, 100 feet may restrict development on an unreasonable percentage of the total land. To ensure that the greenway requirement does not take value from properties unreasonably, no more than 20 percent of any one parcel should be deemed unbuildable under the combined greenway and trail requirement. Parks and other green spaces will be recognized as parts of the greenway system in order to achieve an average width of 100 feet while allowing for the greenway’s narrowing at some points along the river (69).
Courts have upheld city regulations that require owners to dedicate private land for trails and greenways. However, cities may not impose a mandatory requirement for public or city access to that land or remove all or nearly all economically beneficial uses of the land. The courts have repeatedly upheld the legality of zoning ordinances that require public trails or greenways because they provide compelling public-safety, welfare and environmental benefits to the community that justify partial restrictions on land use (70). In October 2006, the New Jersey Supreme Court upheld New Jersey’s 300-foot greenway requirement (71). To avoid a legal challenge, a zoning requirement that requires owners to provide land along the water’s edge in exchange for needed city permits should do the following:
Density bonuses allow developers to maximize the value of their developable land by creating a taller building with more square footage to offset substantial land-carrying costs and the demands of providing a variety of services—including streets and open space—that traditionally were the responsibility of the public sector. In order to create a connected, green, open riverfront, we must recognize that substantial height and density are needed to make construction and debt-service feasible for riverfront property owners.
The greenway in Saint Paul, MN, protects the edge of the Mississippi River and increases property value for nearby residents.
Economic: A greenway will raise property values, reduce stormwater-management needs, increase revenue from bird watching and fishing and create an attractive trail site.
Environmental: A greenway will restore habitats for birds, fish, turtles and other animals, filter pollutants before they enter the river and connect residents with the natural environment.
Community: A greenway will add connected, green public space to the riverfront that will link neighborhoods and create a new destination for neighbors and visitors.
Impact on City Budget: The maintenance cost, based on a study of New York City waterfront public-space maintenance, is $55,000 per acre for maintenance and landscaping and $18,000 per acre for security. This amount does not include funding for environmental remediation in locations with contaminated soil.
The city should consider offering the following incentives to owners who dedicate private land for a trail or greenway:
Greenways around the United States are drawing people, investment and development to waterfront areas. Golden Gate Park in San Francisco raises the values of nearby properties by $500 million to $1 billion and thus generates $5 to $10 million annually in property taxes. In Oakland, CA, a 3-mile greenbelt around Lake Merritt, near downtown, has added over $41 million to local property values. In San Antonio, TX, Riverwalk Park has surpassed the Alamo as the most popular feature of the city’s $3.5 billion tourism economy.
Golden Gate Park, San Francisco, CA