Cities Can’t Prejudge Winner in Green v. Grey Infrastructure Battle
When I was in college, there was always a disconnect between the “civil” and “environmental” parts of my Civil/Environmental Engineering degree. Sometimes it even seemed like the nerds and the hippies were locked in a quiet (but epic!) struggle over the future of the world’s cities. These tensions were an understandable reflection of a persistent trend in the infrastructure community that continues to pit grey (traditional) and green (nature-based) approaches against each other in a quasi-moral battle.
One of the ironies of the green versus grey infrastructure battle is that they are not mutually exclusive approaches; many times the best design solution is a combination of grey and green infrastructure working together. Grey and green infrastructure are on the same team, and that team’s goal is to take action on any number of difficult problems coastal cities are grappling with: hurricane risk, saltwater intrusion, coastal erosion, tidal flooding, sea level rise. Arguing about green versus grey infrastructure makes taking action on these problems harder than it already is.
In the spirit of taking action and focusing on outcomes, here are a few interesting examples of successfully built green and grey coastal protection projects and the innovations that make them stand out.
Green (Nature-Based) Coastal Protection Projects
It is paramount for all nature-based coastal protection projects to plan for, and execute long-term evaluation and monitoring to determine the project’s performance, such as resulting reduction of wave height. This is essential to ensure that more traditional engineers accept these softer solutions as viable. The support of more traditional engineers is key to the replicability and scalability of these nature-based solutions.
- Louisiana’s Coastal Restoration: As a part of a comprehensive plan to reduce coastal risks, the Louisiana Coastal Protection and Restoration Authority has undertaken nearly 150 restoration and protection projects, both green and grey. Of interest is the associated applied research to measure and model the performance of nature-based infrastructure projects on Louisiana’s coast.
- Staten Island Bluebelt (New York): A successful watershed-level approach to green infrastructure to address intertwined problems of coastal risks, flooding and poor water quality. The Bluebelt enjoys a high level of community support because of continued engagement, increases in home prices and cost savings.
- Prime Hook National Wildlife Refuge Restoration (Dover, DE): Integration of storm surge risk reduction and endangered species habitat restoration after Hurricane Sandy. Particularly interesting is this write-up from the US Fish and Wildlife Service that includes process updates from December 2012 through December 2016 (when construction finished) that provide great insight into how the project actually moved forward.
Grey (Structural) Coastal Protection Projects
There are cases when no amount of green infrastructure will solve extreme, chronic coastal flooding. In those cases, it’s a good thing traditional grey solutions are becoming smarter, more flexible, and more sustainable. We should applaud that progress and seek to replicate it, when appropriate. These are some examples I’ve been thinking about recently:
- San Andrés Breakwater (Port of Málaga, Spain): An innovation in breakwater design and materials saved significant time and money in this project. The RFP was written in a way that enabled the innovation in design and materials, which is why the project won Spain’s National Innovation Award for Public Procurement of Innovative Solutions in 2011.
- MOSE project (Venice, Italy): Managers of this project can use real time data to open and close a series of tide gates based on changing tide conditions, making its operation more flexible than a typical tide gate project. Researchers have been simulating the flexible operation of these tide gates since 2011 to prepare for eventual construction completion and operation, expected in 2018.
- West Riser Tide Gate (Meadowlands, NJ): The tide gates include a series of solar-powered sensors that allow managers to monitor performance during storms. The data is posted in real-time so citizens can receive text and email alerts when there’s immediate flood danger. This connectivity is reflective of a broader trend towards open, and usable, data in infrastructure and other essential city services.
The coastal cities that are taking action are generally doing so because they are experiencing real, tangible impacts of coastal flooding today, and they are aware that those problems are going to get worse in the future. In these cities, floods are costing businesses now; they’re increasing insurance prices now; they’re affecting home prices now. These cities don’t have the luxury of discriminating between green and grey solutions. They need the solution that is best for their community. Rightfully so, these cities are focused on outcomes: How many homes will this solution protect, and from what size storms? How much will it cost?
The cities and states that pursued the projects listed above have taken tangible action to mitigate coastal risks. Why have they moved forward, when so many others are failing? Capturing their success factors is important in helping other cities replicate these coastal innovations, both green and grey, in their own communities. Here are some of the factors that may have allowed these projects to move forward:
- Solved an urgent problem (while keeping an eye on the future)
- Prescribed desired outcomes, not specific technology intervention(s)
- Empowered a project champion
- Engaged broadly with their communities, with both the public and private sectors
In a lot of cases, the factors listed above are proxies for political will. For example, when a project solves a pressing problem that matters to citizens, elected officials are likely to enthusiastically support the project. And when there’s political will, projects tend to move forward when they otherwise would not.
I’ve listed a few success factors, but this is certainly not a comprehensive list. There are many important factors that move coastal protection projects forward from initial design to construction and operation. Are there any coastal protection projects you’ve come across recently that inspire you?
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