Climatide

flickr/hollyladd

Moving homes impacted by erosion - like this one on Smith's Point, Nantucket Island - could be part of a strategy of retreat from rising sea level.

From the Cape Cod Canal and New Bedford’s hurricane barrier, to the levees of the Mississippi River, the Army Corps of Engineers has shaped the very landscape of the United States. But many of the Corps’ greatest feats of engineering are coming to be seen as naive, foolhardy, even misinformed attempts to master nature. When it comes to rising sea level, Darryl Fears (Washington Post) reports that the Army Corps’ way may be the way of the past.

… in the past, municipalities turned to a manual published by the Army Corps of Engineers since 1954 on how to protect shores by holding back the sea.

But earlier this month, the U.S. Environmental Protection Agency published the first manual on how not to hold it back, arguing that costly seawalls and dikes eventually fail because sea-level rise is unstoppable.

So what does the EPA suggest instead?

The EPA report said governments have three options to deal with sea-level rise: They can stay on the well-worn path of building expensive protection and raising streets and buildings. They can beat an organized retreat from the shore, perhaps by offering financial incentives to people and organizations to move inland. Or they can allow people to do whatever they want for their waterfront properties but tell them in no uncertain terms that they are on their own when the waters rise.

Those three options are subtly different from the three I’ve presented before. The report lumps hard coastal armoring and softer beach nourishment projects together into the category of “shoreline protection” and adds a category called “accomodation” which is literally half-way between protection and retreat – finding ways for humans to live on naturally evolving coastlines.

The very idea that human habitation and shifting shores are not mutually exclusive is intriguing. In the context of a report that essentially dismisses armoring and nourishment, it promises some hope for coastal inhabitants who balk at the idea of abandoning their homes.

But, in the end, the EPA report is essentially a primer on how to retreat. In fact, what I found even more interesting than the three big-picture options were the three strategies the EPA presents for how to enforce retreat:

Logically, there are three ways to limit the portion of our coast eventually subject to shore protection:
1. Setbacks. Prevent development of some lands vulnerable to sea level rise, either through regulation or by purchasing land (or development rights) from the current owners.
2. Rolling easements. Make no effort to restrict land use but prevent shore protection of some coastal lands either through regulation or by transferring any right to hold back the sea from owners inclined to do so to organizations that would not.
3. Laissez-faire. Make no effort to prevent either development or shore protection, but curtail government subsidies for both, and hope that eventually the forces of nature and economics will lead owners to allow their lands to be submerged.
Each way is appropriate in some circumstances.

No mincing words there. And the EPA reserves some strong criticism for both setbacks and a laissey-faire approach. The report is titled “Rolling Easements” and the body of the report is an examination of “more than a dozen different legal approaches to rolling easements,” so it seems clear which option the EPA favors.

But what is perhaps most significant about this report is its mere existence – a new government primer on par with, but completely contrary to, the Army Corps’ five-decade-old manual on shoreline engineering. James Titus, the EPA scientist who authored the report, described it eloquently and succinctly:

This document presents an alternative vision, in which future development of some low-lying coastal lands is based on the premise that eventually the land must give way to the rising sea.