An Action Plan for the Central Delaware: Obj. 10: River's Edge

“This is a long-term issue, but I think needs to be in people’s minds as well—and that is climate change, sea-level rise and the risk of flooding. A ‘softer’ approach to development and allowing for wildlife habitat could stem that tide. The revival of wetlands along the shoreline could provide a buffer area for flooding.”
Barry Seymour, executive director, Delaware Valley Regional Planning Commission (75)

Walk along the edge of the central Delaware today and you will see cement, trash and the occasional floating shopping cart. You will not see river plants, fish or other signs of a healthy river.

Cleaning and planting the river’s edge will increase the area’s attractiveness to residents, business owners and tourists. In addition, a healthy river’s edge prevents flooding, cleans local air, improves water quality and protects the health of those who live in river neighborhoods. A healthy river’s edge will give Philadelphia a new reason to be proud of its river.

The first step toward creating a healthy river’s edge is to clean up the years of accumulated trash dumped in the water and at the water’s edge and replace the garbage with trees, shrubs and grass wherever they can withstand the force of the river flow. Reconstructing destroyed river wetlands is also critical for two reasons: because wetlands are where thousands of types of fish, birds and other wildlife live, and because wetlands remove dangerous toxins from polluted river waters naturally. Another critical task is to begin to naturalize shorelines where old steel or concrete bulkheads are crumbling and no longer effective by replacing them with sand or rock beaches that will stop erosion, allow the greenway to filter pollution more effectively and allow people to touch the water. Finally, we need to reduce and divert combined sewer overflows that allow sewage to flow directly into the river when the combined sewer system exceeds its capacity after a storm. 

Each of these actions will lower pollution, improve habitat for fish and birds, help manage stormwater and create a healthier, more beautiful river’s edge:

Clean the river’s edge. With the help of Philadelphia Water Department trash boats, Fairmount Park Commission staff and hundreds of volunteers, remove trash from the river’s edge. Pick up litter and garbage. Remove furniture and other items that have been dumped into the water. Create a trash-free river’s edge.

Restore plants to the riverbank. Trees and plants work hard along the river’s edge to filter pollutants, absorb stormwater, beautify the landscape and create habitat for birds and other river animals. Wherever we have the land to preserve a greenway along the river’s edge, plants will line the shores. At locations where a 100-foot greenway is not possible, a narrow line of native plants can still beautify the riverbank. Some pier sites will not have any riverbank areas for planting. These sites will be priority targets for reconstructed tidal wetlands—underwater planted areas.

Reconstruct river wetlands (76). Wetlands, the shallow areas where land meets water, once lined the banks of the central Delaware. Less than 5 percent of the Philadelphia area’s original wetlands remain today (77). Yet wetlands play the crucial role of filtering pollutants out of the water, a service that has been valued at $1 million per mile (78). Wetlands are home to thousands of plants and animals, so by reconstructing wetlands as a part of a plan set out by the Philadelphia Water Department, we can bring many species of fish, oysters and shore birds back to the river. The Philadelphia Water Department has created a list of priority sites for wetland reconstruction, restoration and enhancement along the central Delaware, which includes structurally deficient piers. Structurally deficient piers provide exciting opportunities to create wetlands, as native wetland plants can extend from the water to the pier; thus nature can reclaim the pier. Several publicly owned piers can be used to demonstrate how beautiful and effective these wetlands can be. Private owners may be interested in donating or leasing their structurally deficient piers to the Water Department for wetland creation in exchange for the city assuming liability for the pier.

Wetland credits will allow the restoration or construction of many river wetlands to be privately funded. The federal Clean Water Act requires anyone who places fill material in a wetland area to restore wetlands or construct new ones at their own expense (79). In the last months, several developers have called city agencies and river nonprofits to shop for a compensation wetland site. “Compensation wetlands,” constructed to make up for the permitted loss of another wetland, are often called wetlands credits. Because many property owners along the central Delaware need wetlands credits, private entrepreneurs, city agencies and nonprofits can all invest in producing wetlands, which they can then sell to owners in need of compensation wetlands. This means that wetlands will be constructed at private expense. In addition, where the agreement made with a property owner requires it, the long-term maintenance costs for the site will be covered as well. So one important action step for Philadelphia is to evaluate available sites more extensively and to have sites ready for wetland construction when a developer calls and asks for a site. The Philadelphia Water Department (through its Tidal Wetland Registry) and the Pennsylvania Environmental Council are both working toward this goal. At the present time, it is far easier to build new wetlands on the New Jersey side of the river, but we need them right here in Philadelphia.

Naturalize shorelines. The majority of the central Delaware is separated from land by concrete or steel bulkheads. These bulkheads were built based on the best erosion and stabilization technology of the nineteenth and early twentieth centuries. Today, however, scientists and river users prefer natural shorelines for river areas that are not in a main shipping channel because they look more natural and attractive, restore fish habitat and improve water quality (80). Bulkheads have a limited lifespan of about fifty years, and many of the Delaware River bulkheads north of Center City are made of wood and were installed in 1909 (81). The cost to replace one linear foot of bulkhead is $7,000 to $10,000 (82). This substantial cost alone may encourage property owners to replace bulkheads with natural shoreline (83). A natural shoreline is currently being installed along the Harlem River, with a green seawall made up of stacks of steel-cage containers that are filled with soil and plants (84). A protective breakwater of rock can be seeded with oysters and installed in shallow water to protect the shoreline land and habitat from waves. Where bulkheads are for the most part intact, wetland plants can be placed into the holes and cracks within the bulkhead surface to create a seawall made up of a combination of plants and hard materials.

Reduce, filter and divert combined sewer overflows to create a healthier river’s edge. As is true in many older cities, Philadelphia’s combined sewer system, which carries both stormwater and sewage, discharges wastewater into the Delaware when a storm overwhelms its capacity. These combined sewer overflows, or CSOs, threaten the health of the river’s edge, produce unsightly trash and allow sewage and other pollutants to enter the river. The Philadelphia Water Department is working on long-term solutions to this problem, including the construction of wetlands to filter out the pollutants. In the short term, the health of the river’s edge can be improved by diverting CSOs farther into the river and away from the river’s edge. Distributing CSOs into the deeper, flowing region of the river can create a cleaner river’s edge, one where native plants, fish, shellfish and birds can once again begin to thrive.

Tinicum Marsh, the largest freshwater tidal wetland in Pennsylvania, is a significant naturalized habitat along the Delaware River, outside the project area.