Living by the water offers risks as well as immense benefits, something the region is distinctly aware of in the wake of the destruction wrought by Hurricane Sandy.
Experts say that comprehensively addressing flood risk requires some combination of three strategies: Protection, resilience and insurance.
The first strategy, protection, means keeping floodwaters out. It is effective, but expensive. It requires long-term capital investment in bulkheads, levees and/or mechanical storm surge barriers that can be closed as needed. Preliminary estimates for a barrier at the Verrazano to protect the inner harbor are between $10 billion and $15 billion. There are also maintenance costs. And such structures can inhibit access to the water and harm fish and wildlife habitat. It's also true that the right conditions can overwhelm barriers, as happened during the 2011 tsunami in Japan and with Hurricane Katrina in New Orleans.
The second strategy, resilience, lets floodwaters in and then copes with them through a combination of strategies. The destructive power of waves, though not the slow rise of a storm surge, can be mitigated through sloping banks, restored wetlands and oyster reefs. State and local government can limit development in flood prone areas. Landowners in flood-prone areas can be bought out, as occurs with New Jersey's popular but underfunded Blue Acres program. The Dutch, masters at managing water, are adopting resiliency strategies to complement their protective barriers. They are making room for their rivers by designing levees to be breached, and even moving whole towns out of harm's way. But such an approach is more difficult in densely urbanized cities and neighborhoods with critical infrastructure such as airports and train stations. Our ability to engineer resiliency by allowing streets and parks to flood, while elevating or protecting buildings, is not clear.
The third strategy, insurance, is conceptually simple. We know it will flood at some point, so put some money aside each year to cover the property damage, and when flooding occurs, evacuate the people and use the money to clean up and rebuild when the floodwaters recede. The problem is that climate change is making our actuarial tables useless, and private insurance companies are getting out of the flood insurance business. The federal flood insurance program enables qualified homes and buildings to access insurance, but should it? Potential damages are in some cases so high, such as when flood waters spread toxic materials, that this approach might be fiscally unsustainable. It also relies on getting people, and in particular vulnerable populations, out of harm's way.
As the region addresses what actions to take to mitigate future disasters, it is likely that some combination of these three strategies will be needed. And the balance will be different in different parts of our complex estuary. What we do know is that it will require investing considerably more political attention and capital by our elected officials. As the flood waters recede, we need to ensure that the focus on shorelines doesn't recede as well.