Marine Streets—A Living Marine Edge

New York City (NYC) is one of the greatest marine cities of the world with 520 mi of ever-changing shoreline. Both nature and humanity contribute to these changes, and they can be interdependent reciprocal systems, although they are commonly thought of as opposing forces. As a result, our once rich and dynamic shoreline is often reduced to a single line of bulkhead. The buffering functions of wetlands and these dynamic shoreline ecological communities, which have historically protected the land from storms, have been erased over time. In addition, climate change and the resultant rising tides, increased runoff from development, and upland impermeable surfaces all contribute to flooding and sewer overflows in the NYC area on a regular basis. As NYC continues to promote development on the waterfront (NYC DCP 2011), the existing underutilized street ends have the potential to provide better connection to the waterfront with enormous ecological and social gain. Just as the Milliontrees NYC initiative (NYC DPR 2011) has a great public and ecological value, a “Marine Streets” initiative would help sustain the living resource of the rivers and bays. We envision these Marine Streets as a new street typology—a critical edge which would mitigate both the upland urban runoff and the climatic tidal surges while providing residents with an improved sense of place, the heightened awareness of a great marine city. Functioning ecologically based on the dynamics of the natural wetlands that

Figure 1.

(above) Many existing streets that end near marine zones are solid hardscape with no biotic communication with the adjacent marine environment. This location (Java Street, Greenpoint section of Brooklyn, NY, looking west) is typical with historic cobble pavement, cement sidewalks and complete lack of amenity or bioengineering plants. (below) Street ends are devoted to traffic barriers, such as these concrete “Jersey barriers.” No expression of coastal landscaping or consideration for bioengineering of storm water runoff or tidal surges has been incorporated into the surficial design. Photos by Martin J. Barry.

used to be prevalent here, they would remain accessible for human use with careful planning and design. These improvements could be made now, concurrent with, or prior to planned development, providing a means to improve the environment within the existing redevelopment framework of streets and blocks.

Figure 2.

Profile of a typical Marine Street.

Dead end streets exist in all 5 boroughs of NYC, present on approximately 25% of the shoreline. Most are underutilized and support little vehicular or pedestrian traffic. The paved surface is often in poor physical condition, and there is a barrier between the land-water interface, often a fence, which prohibits access to the water’s edge (Figure 1). Changing these poorly used streets to Marine Streets would provide an infrastructure that meets both ecological and social needs.

The ecological function is 2-fold: it will address storm water runoff from the upland as well as storm surges and rising tides from the marine waters. New York City currently spills 1.89 × 10⁹ L (500 million gallons) of combined storm water and sewage overflow from the uplands into waterways per week on average (Riverkeeper 2011). Because sewage and storm water are collected in the same pipes, sewage floods directly into rivers when the system is overwhelmed by storms. The basic idea for Marine Streets is to remove the asphalt street surface and replace it with a permeable surface that allows the landscape and soils to move, store and filter rainwater, reducing runoff into the rivers and storm systems. This would help improve water quality by slowing the quantity of runoff into the combined system and reducing the amount of sewage released into the rivers. The quality of the water reaching the river can also be improved by filtering the water through various types of vegetated filters (bioswales, filter strips, rain gardens, etc.) which reduce, minimize, or remove suspended solids and heavy metals (30–90%), nutrients such as phosphorous or nitrogen (10–65%), and oils and grease, depending on the particular design of the...