Visitors to Bayonne know it as the Peninsula City. Surrounded by water on three sides, it connects parts of New York and New Jersey with renowned arch bridges. If you are a resident of Bayonne, the rainwater is your point of interest. Experiencing only about five minutes of downpour will teach you everything you need to know about the current stormwater runoff controls. If you reside in a low-lying area, your basement is likely useless for anything but holding floodwater. If you own a vehicle and a storm hits town, you must rush outside to move the vehicle before rising water levels forever change the smell of the carpets, or worse, ruin the electrical wiring harness.
Local flooding is a result of several dynamic factors working in unison that can, at times, overwhelm the current sewer lines. Bayonne’s sewer system, now more than a century old, was designed without any foreseen comprehension of the current population density, water usage, or increased storm ferocity. It is a combined sewer system, meaning it is used to convey both sanitary and storm flows. During heavy rain and snowstorms, combined sewers receive higher than normal flows at times, but treatment plants are unable to accommodate flows of more than twice their design capacity. When this occurs, a mix of excess stormwater and untreated wastewater pours directly into the city’s waterways at certain outfalls. This is referred to as a combined sewer overflow (CSO). CSOs are a concern because of their effect on water quality and recreational use of local waterways.
Bayonne is relatively flat — with its highest point only seven feet above sea level — and has the highest number of CSO outlets in the state. The city is one of 21 New Jersey municipalities mandated to drastically reduce the amount of CSOs entering waterways to comply with New Jersey’s 2015 Clean Water Act. The city and Suez-Bayonne have submitted an action plan to reduce the sewer systems’ dependence on overflow occurrences and address localized flooding, with estimated costs of $300 million to the state Department of Environmental Protection for approval — the single greatest infrastructure investment the city has ever made. However, it relies heavily on human-engineered solutions in concrete and steel materials known as gray infrastructure.
This approach should be re-evaluated to include a combination of sustainable, environmentally friendly green infrastructure programs (programs that restore or mimic the natural water cycle), new development planning requirements to offset the city’s financial obligations, and gray infrastructure that adds community benefits.
Combining gray and green infrastructure
The long-term gray infrastructure mitigation plan submitted to the DEP depends heavily on Bayonne’s stormwater control and underground storage upgrades because, according to the city, these are the most feasible approaches to address flooding.
This program uses engineering methods to evaluate what volume the current system can handle, the number of tanks that will need to be installed underground to pool overflow, and the effective use of pumps between the two aspects. This is a concrete-engineered system to mitigate future flooding, similar to the system designed a century ago that is now failing us. Local officials, however, were quick to dismiss the inclusion of green infrastructure within the plan. According to Bayonne’s Department of Public Works manager Timothy Boyle, a long-term control plan with heavy reliance on green infrastructure could cost as much as $1 billion, more than three times the cost of the current proposal. Boyle publicly stated that “[Bayonne is] an urban environment and, as nice as it would be to think of parks as the last bastion of the trees, green infrastructure is very poorly understood. There’s a great deal of engineering and math involved in it.”
The city has doubled down on this posture in its first phase of the plan by installing underground storage tanks at Fitzpatrick Park while reducing the number of trees being replanted.
The concept of green infrastructure is the opposite of gray infrastructure. The implementation of green infrastructure aims to capture and divert stormwater prior to it entering the sewer system. This is done by installing green roofs, rain gardens, rainwater harvesting barrels, bioswales, permeable surfaces, planter boxes, and other stormwater collection methods. The more water collected at the source, the less the system has to manage. This method alone will not solve flooding issues but will assist in localized overflows.
Green infrastructure can cost less
In addition, contrary to the statements made by Mr. Boyle, green infrastructure can actually cost less. According to a study by the American Society of Landscape Architects, local and state governments are wasting billions of dollars each year by not going green. Looking at 479 case studies of green infrastructure projects around the United States, the report found that the majority of projects turned out to be equally affordable, if not more so, than traditional gray infrastructure. About a quarter of the projects raised costs, 31%, kept costs the same, and more than 44% reduced costs overall.
Bayonne has an opportunity to set the standard for innovative ways to combat local flooding, which other New Jersey municipalities will follow. Through ordinance enforcement, the city should re-evaluate all future development plans to include sustainability requirements. In this reassessed plan, green roofs and the installation of storage tanks under the sidewalks would be required for any new development or existing infrastructure that undergoes construction improvements of 50% or more of its market value. These storage tanks will collect rooftop and sidewalk runoff as well as slow down buildings’ sewage output. The water from these systems will then pool in the storage tank and flow slowly into the sewer system, mitigating excessive overflow. This plan may be easier to negotiate with the city’s ability to incorporate it into payment in lieu of taxes (PILOT) agreements. There are currently thousands of units approved for construction under tax incentive agreements that do not require flood mitigation infrastructure.
Another possible solution to help prevent CSO while benefiting the community is to complete the long-anticipated Hudson River Waterfront Walkway, a project 30 years in the making. The ongoing and incomplete project — located on Kill Van Kull and the western shore of Upper New York Bay and the Hudson River — was implemented as part of a New Jersey state-mandated master plan to connect municipalities from the Bayonne Bridge to the George Washington Bridge with an urban linear park, providing contiguous, unhindered access to the water’s edge. While many of the areas north of Bayonne have been completed, much of the Bayonne region itself has not.
During the future implementation of this project in the Bayonne region, which will involve construction over CSO outputs, massive storage tanks can be built in the underbelly of the walkways. These storage tanks will capture combined water, holding it while the system is inundated by storms. Once weather improves, the water can be pumped back into the system, flowing to water treatment plants. In areas where the walkway is elevated, this will also ensure storm surge protection from rising seas while providing the community a safe and scenic route to run and bike.
It will take years to solve
Like many New Jersey municipalities, Bayonne’s unique land mass, density, and combined sewer system create a complex environment to solve local flooding issues and regulate overflow. Undoubtedly, achieving this will take several years, resources, and evolving plans. Solely focusing on gray infrastructure projects to manage water that has already entered the system is a narrow-minded approach. The administration and Suez-Bayonne should review and conduct feasibility tests on the ideas presented here before ruling them out.
Not all projects should be evaluated solely by cost. Certain projects may incur added costs within reason but provide greater alternate benefits to residents such as retaining valuable urban green space. It will require a combination of both green and gray infrastructure to effectively change the future of our streets and waterways while adding public and environmental benefits.