Guaranteeing Infrastructure Investments
Background and Key Considerations

Dating back to the original transformation of Gowanus Creek into the Gowanus Canal, there has been intensive human intervention on the natural marshlands and topography of the watershed. Gowanus faces a number of interrelated environmental challenges, generated in large part by historic industrial uses and the complex, historically undersized sewer infrastructure that was originally designed to overflow into the Canal, which was both a waterway and open sewer. However, the infrastructure challenges are not exclusive to this legacy. Other challenges include open space that is at a premium and school seats that are in short supply.

The term infrastructure is used here to refer to environmental systems that keep the area clean and healthy; physical open spaces that provide important amenities and intra-community connectivity; transit systems into and out of the area; and public institutions such as schools.

Industrial Contamination of the Canal

One hundred years ago, the Gowanus Canal was a major transportation route for nearby industrial uses such as manufactured gas plants, tanneries, and chemical and dye plants. Long after the offending users along the Canal have departed, the contaminants left behind in the soil and sediment of brownfield sites continue to migrate into the canal.

More than a dozen contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and heavy metals such as mercury, lead, and copper, have been found in high levels in the sediment along the floor of the Canal. PCBs were used as coolants and lubricants in electrical equipment and were banned in 1979. PAHs are legacy contaminants that formed when coal, wood or other organic matter were being burned by industry along the Canal. Both PCBs and PAHs are suspected of being carcinogens, and PCBs are believed to impact neurological functioning. The water itself has also been found to contain PAHs and heavy metals.

In 2010, in large part due to the Gowanus community’s strong environmental advocacy, the Canal was added to the Federal Superfund list of most contaminated hazardous waste sites in the United States. The Superfund program operates on the principle that the parties legally responsible for the contamination, rather than taxpayers, should pay for the costs of investigation and cleanup. A plan to clean the Canal known as the Record of Decision (or ROD) was released in late September 2013.

Waste and Storm Water Management Issues

On top of decades of industrial discharges, frequent combined sewer overflows (CSO) that mix sanitary waste with rainwater have led the Gowanus Canal to become one of the nation’s most seriously polluted water bodies.

There are many issues that need to be addressed regarding the functioning of the current waste and storm water management system. From the sewer system, the Canal is the destination of multiple combined sewer overflow outfalls, which deliver a combination of ground-level water run-off, chemicals, and other materials that water conveys, and the sewage that the system cannot handle during extreme rain events.

The City’s sewer system functions primarily through force of gravity necessitating large collector or “interceptor” lines to be located in low-lying areas such as Gowanus. Much of this infrastructure was built around the turn-of-the-century and has seen minimal care until recent years. This infrastructure includes the Bond-Lorraine Sewer, which runs south under Bond Street along the west side of the Gowanus Canal and then west under Lorraine Street until it connects with the Columbia Street Interceptor in Red Hook. Other aging infrastructure includes the Fourth Avenue Sewer, which runs south along the east side of the canal, and the Gowanus pump station located at the head of the canal on Butler Street. This infrastructure accepts much of the sewer and storm water flows from areas upland and outside of the Gowanus neighborhood (see Fig. 1). The results of this poorly maintained and undersized sewer system include street and catch-basin flooding, basement flooding, and sewer back-ups.


Sub-Sewersheds that impact the Gowanus Area_19NOV_v1

Flooding is a major issue that arises even during normal rain events in the neighborhood, caused in large part because the area is low-lying and has insufficient storm management infrastructure to absorb the amount of storm water generated. Rivers of water regularly flow along Fourth Avenue, Ninth Street, and elsewhere during heavy or prolonged rain. Basement flooding and sewer back-ups are common in private homes and businesses, and they are acutely and consistently experienced in the NYCHA public housing developments. Complaints about these issues are common and widespread. Figure 2 provides a snapshot of their extent.


Flooding and Sewer Problems in Gowanus_19NOV_v1


Climate change has also made the area increasingly vulnerable. Superstorm Sandy wrought devastating impacts on Gowanus. Flood waters inundated building systems causing loss of power and heat for residents and businesses, destroyed merchandise and materials, and disrupted daily activities for weeks on end.

There is concern about the need to better understand how site-by-site interventions to mitigate flooding from rain- and storm-surges impact the area’s hydrology. Specifically, this concern involves piecemeal re-grading of development sites, namely the Lightstone development, which could adversely impact surrounding properties by pushing floodwater to nearby properties and impede drainage from properties further inland and uphill.

Air quality is another environmental issue of community concern. Truck traffic and traffic from buses that park in the area emit pollutants such as particulate matter that at high levels are linked to respiratory illness.

Lack of Public Open Space and Transit Service

In addition to these burdens, the Gowanus neighborhood is also underserved by open space resources and public transit. There are only a few open spaces, which are fairly small and disconnected from each other. They are extremely well-used by the local community. Public open spaces have been identified by local stakeholders as places of opportunity to foster arts activities while also addressing environmental issues such as improving storm water retention. However, these existing spaces are in need of improvement and increased maintenance to better meet their current and envisioned functions, and would benefit from measures that enhance physical access to them and connectivity to each other. The areas bordering the Gowanus Canal itself have also been identified as potential places to increase publicly accessible open space.

As a whole, Gowanus is difficult to traverse. Increased transit service for residents, especially workers, has long been articulated as a priority for the community, along with improved pedestrian, biking, and boating infrastructure. The Gowanus Dredgers, an important and growing group of mariners, have a unique perspective on accessibility issues along the Canal and should be included in solutions for the area.

Need for Additional School Facilities

Gowanus faces a shortage of public school seats for local students. The School Construction Authority’s Capital Plan for 2014-2019 identified a need for 4,000 new seats in District 15District 15 includes Cobble Hill, Carroll Gardens, Red Hook, Sunset Park, Park Slope, Windsor Terrace, Kensington, and encompasses most of Gowanus. and provided funding for 2,200 of those seats. Within these projections was an identified need of 640 seats in the District 15 sub-area that includes Carroll Gardens and Gowanus, and 1,096 seats in Park Slope (the majority of the need was in Sunset Park). These projections are based on current land uses, so they consist of estimates of new development on land zoned for residential development (e.g. the Lightstone project); however, they do not include additional capacity that would be required as a result of future rezonings allowing residential development.

The number of pre-kindergarten seats is also insufficient and the recent expansion of New York City’s Universal Pre-K program requires schools and providers to identify new spaces in an already overcrowded district. A June 2014 analysis by WNYC’s “SchoolBook” initiative showed that in Park Slope and Gowanus, there were only 30 pre-K seats for every 100 4 year-olds.

New school seats must be provided to accommodate school children and solving this need presents an opportunity to simultaneously meet other community goals. For example, new school facilities could provide publicly accessible space for arts, cultural, and community activities, which is also limited in Gowanus.

PS 32 (the Samuel Mills Sprole school at 317 Hoyt Street), which serves much of the Gowanus area and shares the building with MS 442, is a good example of the strengths and challenges faced by schools in the district. The school’s vibrant library program, ASD/NEST program for children on the autism spectrum, frequently-used auditorium, after-school programs sponsored by Good Shepherd Services and the Brooklyn Historical Society, interactive garden, and advocacy for the Gowanus Houses Community Center, all make it a hub of Gowanus community life. However, the school is forced to rely on classroom units in impermanent structures and class sizes are growing.

Improvement Projects in the Pipeline

Despite the above challenges, there are a number of environmental infrastructure upgrades planned for Gowanus, as well as a broad vision for open space that serves both recreational needs and improves environmental quality of the area. Significant upgrade projects aimed at addressing the issues described above are underway, as well as additional longer-term projects that upon completion, will have a dramatic impact on the ability of water-systems infrastructure to serve the area and improve local environmental quality.

The Superfund plan to clean the Canal was released by the U.S. EPA in late September 2013 and contains provisions for dredging the contaminated sediment from the floor of the Canal (slated to begin in 2016) as well as an effort to significantly reduce combined sewer overflows into the Canal. This plan includes two retention tanks designed to significantly reduce the overflows by capturing the excess waste water from outfall drainage areas on the east and west sides of the Canal. These must be installed at sites that are supported by science and engineering, while also agreed to in dialogue with residents and without compromising public open space and recreation. The tanks are expected to be sited by summer 2015.

At the head end of the Canal, NYC DEP has repaired and upgraded the 1.2 mile Gowanus Canal Flushing Tunnel to pump as much as 252 million gallons of fresher water (from Buttermilk Channel) into the Canal each day. The Gowanus Pump Station is also in the process of being upgraded. This project includes installation of a new mile-long force main that will pump sewage from the head end of the canal, through the Flushing Tunnel, and to an interceptor under Columbia Street, thereby reducing CSOs into the canal by 34% each year.

Another project underway is the Green Corridor for 6th Street, a model green infrastructure (GI) project that broke ground in October 2014. Gowanus Canal Conservancy managed the design and construction of this project, working with EDesign Dynamics LLC, Drexel University and Perfetto Contracting Co. Funding was provided by DEP and the EPA. GI uses vegetation, soils, and natural processes to manage water and create healthier urban environmentsDefinition courtesy of the EPA: through landscape elements such as bioswales, green roofs, and porous pavement. The Green Corridor’s network of eleven bioswales will collect storm water from adjacent streets, reducing combined sewer overflows into the Canal.  The curbside areas that capture water also enhance the streetscape with trees, native grasses, and flowers. The project will be closely monitored for several years to measure and record water volumes captured, pollutants removed, and the extent to which air temperature is moderated.


Bioswales, a type of green infrastructure, on the 6th Street Corridor Credit: Gowanus Canal Conservancy

Bioswales, a type of green infrastructure, on the 6th Street Corridor
Credit: Gowanus Canal Conservancy


A portion of the proposed Sponge Park is now under construction, with expected completion by the end of 2016. The Sponge Park will eliminate surface storm water run-off entering the Canal from 2nd Street through a demonstration of green and environmental infrastructure. Concrete cells filled with soil will be installed under the street to catch and filter storm water before it runs into the Canal. The park will be covered with plants that naturally absorb or breakdown toxins, heavy metals, and contaminants from sewer overflows, along with plants that soak up excess water.Concept by Gowanus Canal Conservancy and dland Studios

Work has also begun on a High Level Storm Sewer (HLSS) pilot project (also known as a “sewer separation” project) to reduce CSO discharge at the Carroll Street outfall. This is scheduled for completion in the next decade. HLSS are an effort to limit CSO events and alleviate pressure on the combined sewer system. They are designed to capture 50% of rainfall before it enters traditional drainage systems and divert it directly into the waterways through permitted outlets, reducing the volume of flows that pass through the combined sewer system. They also have the benefit of alleviating street flooding in problem areas. Due to HLSS requiring special siting considerations, the Gowanus HLSS is one of only seven such efforts in the city.

Finally, in the 2013 report issued by Mayor Bloomberg’s Special Initiative for Rebuilding and Resiliency (SIRR), the City indicated that a storm surge barrier (such as a floodgate) along the Canal may be necessary to protect the community against increased storms the area will face due to climate change. The City called on the U.S. Army Corps of Engineers to work with them to develop an implementation plan and preliminary designs for a local storm surge barrier along the Gowanus Canal. In June 2014, the NYC Office of Recovery and Resiliency issued an RFP for a feasibility study and is moving forward to assemble a team of experts to study the related issues of coastal protection and storm water management. While this study was originally focused more narrowly on an analysis of floodgates, the de Blasio Administration agreed to broaden it. This was in response to feedback based on the desire expressed by Bridging Gowanus residents for a hydrology study to include a broader review of storm water management, run-off, water-flow, and coastal protection issues.

Many of these resiliency infrastructure improvements, as well as the previously mentioned open space improvements, have the potential to meet multiple community goals simultaneously, through design that improves connectivity and green space. However, the planning for these infrastructure upgrades is often done in silos. Coordination across projects and agencies, in close communication with community stakeholders, is critical to achieving the best possible environmental recovery of the area.