Adapting to Climate Change Impacts on NYC Wastewater Systems

Client: New York City Department of Environmental Protection
Location: New York, NY

Hazen and Sawyer, as part of a joint venture, is identifying and quantifying the impacts of climate change and population growth on New York City’s sewer, drainage, and wastewater systems, and recommending adaptation strategies to manage risks. The strategy includes evaluation of waterfront facilities and infrastructure vulnerable to flooding and other operational impacts. Following the impacts of Hurricane Sandy, the project was expanded to include vulnerability analyses and adaptation recommendations for all at-risk city wastewater treatment plants (WWTP) and pumping stations (PS).

NYC needs to proactively prepare to minimize the impacts of global climate change, including rising sea levels, increasing storm frequency and intensity, and elevated surface temperatures. As a densely-populated coastal city, NYC has unique challenges with respect to wastewater treatment and collection infrastructure.

Like the many at-risk wastewater treatment facilities shown in the map of New York City at right, the Hunts Point plant resides well within the 100-year flood zones, and is particularly vulnerable to surge. In all, the study found that all 14 wastewater treatment plants and 58 of the 96 pumping stations in New York City are at risk from future, large surge events.

The team assessed the vulnerability of infrastructure and prepared recommendations for the study drainage area and select wastewater treatment facilities. The team also defined adaptation recommendations for all WWTPs and PSs at risk of inundation during extreme storm surges.

Project Outcomes and Benefits

  • Developing a long-term adaptation and optimization strategy, based on defined deterministic metrics, to ensure the City’s water infrastructure will be robust enough to withstand predicted climate change scenarios.
  • Defining adaptation recommendations for all WWTP and PS at risk of inundation during extreme storm surges.
  • Updating “intensity-duration-frequency curves” for rainfall in NYC and defined a new ‘”typical year” for drainage analysis.
  • Identifying critical system thresholds and vulnerabilities and cost-effective and environmentally sustainable adaptation solutions in order to make site-specific adaptation recommendations.
  • Collaborating with City planners, engineers, and operations staff at the earliest possible stages to maximize value across the City’s missions and ensure immediate integration of climate change adaptation.

For more information on this project, or to discuss a similar project in your area, contact Sandeep Mehrotra at