Planning for a Coast with Fewer People
Census data tell us something vital about the future of towns and cities, but what about coastal ecosystems? Recent census data paint a picture of pervasive decline in population for the Louisiana coastal region around New Orleans. Coastal areas in the US enjoyed booming growth during the period 1970 to 2010. Population in all coastal counties increased by 39%. However, against this background New Orleans stands out as a conspicuous “cold spot” of declining population. The population of the three counties that make up the New Orleans metropolitan area declined by 18% over the same period.[1]
For purposes of argument, let’s say that coastal Louisiana has entered a period of sustained population loss. What does this mean for coastal communities and coastal ecosystems? How do you plan for a coast with fewer people?
A Reasonable Response
First, we need to set aside the ingrained bias of our growth-oriented culture, which is to regard declining population as bad. Quite the opposite, the decision by people to move away from the coast is a reasonable and rational response to current conditions. People threatened by natural hazards have only three basic strategies to protect themselves; call them plans A, B and C. What a person chooses to do depends on personal circumstance, cost, and their confidence that a strategy will work.
Plan A is to prevent loss or damage from occurring. In this case, where the threat is coastal flooding from storm tides and hurricane surge, this means building and maintaining large dikes and floodwalls to protect cities and towns.
Everyone knows how well this strategy has worked in Louisiana. Before the devastation of Hurricane Katrina, in 2005, New Orleans suffered similar flooding from Hurricane Betsy in 1965.
Plan B is to avoid loss or damage from occurring. In the short-term this means placing valuables up out of reach of floodwaters and getting out of town when a storm blows in. Over the long-term this means packing things up and moving out, permanently.
Choosing to pack up and move out is difficult, but it is also deeply rooted in the shared American experience. This is what the first colonists did when they fled persecution in Europe to begin anew in North America. This is what their decedents did when New England farmers traded their hardscrabble plots for more fertile lands on the prairies. And, this is what the prairie farmers did during the 1930s Dust Bowl when they abandoned their parched and eroding farms.
Plan C is to accept that flooding is inevitable and find ways to cope. Building resilient communities that are able to recover quickly from flooding when it occurs is one way of coping.
A decrease in population provides existing towns and cities with opportunities to adopt new measures that increase their resilience. For example, the current population of New Orleans is slightly more than half of its peak 1960 population. Much of the area within the protective dikes that was needed for housing in 1960 now can be used provide temporary surface water storage, as shown here. This is a new strategy for resilient urban design that the Dutch call “making room for water.”
An Ecological Renaissance
Alan Weisman, author of the 2007 best seller The World Without Us, presents readers with a challenge. “How,” he asks, “would the rest of nature respond if it were suddenly relieved of the relentless pressures we heap on it and our fellow organisms?” He answers this question, in part, by visiting various places that are off limits to people. He visits the demilitarized zone along the border between North Korea and South Korea and the region surrounding the site of the Chernobyl nuclear accident. In these places, without people, an ecological renaissance has occurred.
We can expect something similar to happen along the coast. As people leave threatened homes and communities, they also leave space for other species to expand and flourish. But more importantly, where there are no permanent human settlements, then there is also no need for disruptive supporting infrastructure. Structures like protective dikes and elevated roads, for evacuation routes, prevent the free circulation of water and sediment needed to sustain healthy, productive estuarine ecosystems. Fisheries and other natural resources of the coast are enhanced where these structures can be removed or where there is no need to build them in the first place.
What Does This Mean?
Given current trends, probably there will be fewer and fewer people living along the Louisiana coast in the future. We must recognize that people will continue to make the reasonable decision to move away from vulnerable coastal locations. Also, recognize that this decision pays benefits on three different levels. First, the individual benefits directly by eliminating the constant risk of damage and loss from flooding. Second, communities benefit from a reduction in the expense required to maintain protective infrastructure, like dikes and evacuation routes. Also, communities with fewer people have greater opportunity to adopt measures that increase resilience to flooding. Finally, natural resources benefit from the relief of disruptive pressures associated with supporting permanent human settlements within estuarine ecosystems.
The story starting to unfold here in coastal Louisiana sets the stage for what will eventually begin to happen elsewhere. Many expect that climate change soon will kick sea level rise and coastal storms into higher gear, increasing the vulnerability of coastal flooding everywhere. Perhaps this has already begun. Very likely, by the time of the 2020 census more coastal communities will be entering a period of declining population and asking, “What does this mean?”
Notes
- County-level population data are available from this website. Population of the New Orleans metropolian area in 2010 was 25% below its peak in 1980, with most of that decline occuring since Hurricane Katrina in 2005.
