Hurricane Sandy’s unprecedented destruction served as a wakeup call to New York City and other urban populations across the world: we need to strengthen our cities’ infrastructure to protect against climate change and extreme weather events. And what is the most cost-effective way to do this?

The Nature Conservancy and CH2M analyzed options for Howard Beach in Queens, New York, and found that green and gray infrastructure can work together to make a community more resilient to flooding and other climate change effects. The first-ever analysis of its kind, Urban Coastal Resilience: Valuing Nature’s Role, demonstrates the value of using hybrid approaches consisting of both gray infrastructure (such as sea walls and flood gates) and green solutions that use the natural environment. Investing in these hybrid approaches can help communities avoid future costs while providing critical climate change resiliency.

“The type of analysis in the Urban Coastal Resilience Report complements the work done in OneNYC, New York City’s strategic plan, and is a great example of how the public, private, and non-profit sectors can be ready to withstand and emerge stronger from the impacts of climate change and other 21st century threats,” said Daniel Zarrilli, Director of the NYC Mayor's Office of Recovery and Resiliency.

Engaging all three sectors in the common goal of protecting the community means more than explaining engineering alternatives; the financial costs and benefits for all stakeholders must be clear. Traditionally, studies like this would quantify the expected cost of damages from storms and flooding—such as insurance and property damage—and compare that to the cost of the infrastructure required to prevent that damage—how high a concrete seawall should be constructed, for example.

This Urban Coastal Resilience study took it a step further, applying an innovative approach to color a vivid financial picture. Ecosystem functions and services are included in the cost-benefit analysis, capturing the value of what nature provides to the community. For example, coastal marshes absorb tidal energy and help protect the community and its infrastructure, as well as providing habitat for shorebirds.

The hybrid alternative could save Howard Beach up to $244 million from storm-related damages while enhancing the environment and community’s economic value and quality of life.

“CH2M is very excited to have contributed to this project through our engineering of alternatives, our detailed coastal and flooding analyses, and the cutting edge economic analysis (assisted by TetraTech) that goes beyond merely looking at the cost of protecting assets from flooding but also considers the economic value of the goods and services that nature provides to society,” said Jonathan Goldstick, Vice President at CH2M.