A March 19 Sustainable City Network article detailed how coastal communities in the United States are preparing for predicted sea level rises over several decades. Globally, sea levels are predicted to rise at a faster rate than in the last several thousand years.
“Science is pretty clear. Sea level is rising and it has risen significantly in the last 100 years. The most robust numbers are from the U.S. National Research Council (suggesting sea level rise over the 21st century of between 22 and 79 inches). But it is difficult to predict,” [Chief Deputy Director of the San Francisco Bay Conservation and Development Commission (BCDC) Steve] Goldbeck said. “We don’t know, for example, how much greenhouse gases will be emitted in the next several decades.”
The U.S. National Oceanic and Atmospheric Administration reports that sea level worldwide is currently rising by about 0.118 inches per year, which is “a significantly larger rate than the sea-level rise averaged over the last several thousand years …”
In the article, Goldbeck and others stressed the need for coastal regions to incorporate sea level rise into their planning and land use processes.
“Really, it’s more important that people start planning immediately for a rise in sea level. BCDC, which has served some 100 cities in nine California counties for more than 20 years, is trying to be resilient to a range of sea level rises. We have a mandate to plan for the Bay and its shoreline as a regional state agency,” Goldbeck said. “People need to make sea level rise part of the planning for a number of threats and issues. For example, we know we are going to have a major earthquake here again. We already face the potential for flooding and extreme storms. We must have a regional strategy for the bay in planning at all levels.” …
For those who haven’t begun seriously addressing sea level rise, [San Franscico Planning and Urban Development Association (SPUR) Sustainable Development Policy Director Laura] Tam suggested that the best place to start is a comprehensive risk assessment.
“Understand what projections are most applicable, what are you going to face and where,” she said. “Coastline makeup and tectonic movements will affect any ocean rise. Create coastal inundation maps that show what land would be covered by a rise.”
Building codes also have to be amended to account for sea level rise, Tam said. Structures need to be properly designed and funded so that future changes can easily be made, for example, raising the height of sea walls or levees. Any design and financial strategy needs to offer protection well into the next century.
The article also discussed actions being taken by various East Coast regions, including Cape Cod, the New Jersey shore, and South Florida. Such actions include permitting and zoning changes; building code revisions; coastline “undevelopment”; and the construction of dunes, beachheads, and seawalls.
In Maryland, a workgroup met over the 2013 interim to study the issue and the Department of Natural Resources has proposed legislation (HB 615) that would create a Coast Smart Council that would develop building and planning criteria for State facilities and projects located in areas subject to flooding or sea level rise. The bill has passed the House with minor amendments and has been assigned to the Senate Education, Health, and Environmental Affairs Committee. A Senate hearing date for the bill has not yet been set.