Sustainability
In 2017, New York City recommitted to the Paris Climate Agreement through Executive Order 26. Releasing the 1.5 Climate Action Plan, the city committed to more aggressive near-term climate change mitigation goals, building upon the existing sustainability efforts in the Roadmap to 80x50 and the DOT Strategic Plan. A core goal in the city’s climate change mitigation strategy is growing the share of trips made using sustainable modes— transit, walking, and biking—from 66% to 80% by 2050. Prioritizing these modes in order to enhance safety and inclusivity also creates a more sustainable transportation system.
Resiliency
Resilient design enhances a street’s ability to continue service during, or return to service quickly following, an extreme weather event. Climate hazards and infrastructure failures (e.g. power grid failure) can cause cascading impacts, highlighting the importance of planning and designing for continuity of service. FHWA provides the following definition of resiliency:
“The ability to anticipate, prepare for, or adapt to conditions or withstand, respond to, or recover rapidly from disruptions, including the ability to:
- Resist hazards or withstand impacts from weather events and natural disasters.
- Reduce the magnitude or duration of impacts of a disruptive weather event or natural disaster.
- Have absorptive capacity, adaptive capacity, and recoverability to decrease project vulnerability to weather events or other natural disasters.”[1]
[1] Resilience Definitions, FHWA Resilient Pavement Definitions. Accessed February 10, 2025
At the network level, resiliency helps maintain access to critical facilities, such as hospitals, shelters, and cooling centers during weather events and climate disasters. In this way, resiliency is both an asset characteristic and an approach to ensure user safety and comfort. Evaluating climate-related risks, their triggers, and thresholds during the design process is essential. The NYC Hazard Mitigation Plan Update identifies the following hazards:
Many of the design strategies and examples in this document address the hazards above in part or indirectly. For instance, trees mitigate both poor air quality and high winds. Bollards and granite blocks may be used to protect pedestrians from terrorism. However, flood protection systems are given a stand-alone section below, given how often their use is singular, how novel they are to New York, and how physically prominent they are in places where they interact with the right-of-way.
Flood Protection Systems (FPS)
Following Superstorm Sandy, New York has advanced an ambitious portfolio of coastal storm protection systems – some completed and more in design. While each project is designed as a system to provide flood protection to a neighborhood, the system is often designed with many different elements which may include, but are not limited to, raising streets, creating landscaped berms, and building a combination of permanent flood walls and deployable flood barriers.
The distribution and siting of these elements is determined by the elevation of an area relative to its flood risk and the level of flood risk protection that elements are designed to provide. Typically, flood protection systems have more prominent elements closer to the coast, where the existing elevation is lower, and less prominent elements further inland on “high ground.” Tie-backs may include any of the elements listed further above, but specifically connect the portion of a system that is providing the greatest protection near the coast with high ground inland. Consult the latest version of the MOCEJ Climate Resiliency Design Guidelines.
Flood protection projects have introduced a new infrastructure typology to the urban landscape in NYC. While many area-wide FPS will be designed and constructed by other City, State, or Federal agencies (e.g. DEP, EDC, DDC, BPCA, USACE), DOT review and approval is generally required when the alignment of an FPS crosses or otherwise enters the public right-of-way. In such cases, designs must minimize impacts to DOT assets while maintaining safe and functional circulation for all users.
Urban design considerations are especially important for FPS elements permanently above ground, such as deployable gates, floodwalls, fixed columns, or other ancillary structures (e.g. a power unit used to close and open a flood gate). Achieving required design flood elevations (DFEs) while preserving sightlines, lighting, access and circulation is a central challenge when integrating flood protection into the street network.
FPS can be broadly classified into passive and active, each with distinct features and operational requirements. Most systems in NYC combine elements of both.
Passive elements, which do not have moving parts, include flood walls, buried flood walls or berms, and raised roads including ramps. These systems provide continuous protection in a wide range of storm scenarios, including smaller, more frequent storms, without requiring crew activation (making them both reliable and low-maintenance).
In contrast, an FPS that crosses a roadway, greenway or sidewalk will often have active or operable elements to allow circulation and property access during regular weather conditions. These deployable components include, but are not limited to, roller gates, flip-up gates, and swing gates. The trade-off to the moveability and flexibility of these active elements is their greater complexity and cost: regular maintenance and inspections, trained personnel to deploy during storms, and secure storage when not in use.
Flood Gate Types
Flood gates are an integral component of flood protection systems (FPS), particularly in urban settings where space is limited, and flexibility is essential. Various types of flood gates can be employed, each with unique benefits, design considerations, and best practices for implementation.
Implementing resilient flood protection systems in the public right of way requires a combination of strategies tailored to the unique challenges of New York City. By integrating various types of FPS such as flood walls, gates, and berms, the City can enhance its flood resiliency, ensuring safety and functionality during flood events. Regular maintenance, testing, and clear operational procedures are critical components of effective flood resiliency planning.
The following section describes the three most common gate types: