The question of coastal protection, which is handled very differently in different parts of the United States, is getting even more complicated than it used to be. In addition to the question of what types of erosion protection will be allowed, states are now grappling with the prospect of rising sea levels and what sort of legislation they should enact to deal with the problems it might cause.
Much of the California coast, for example, is hard-armored with rock, sea walls, and other permanent structures. In other states—Oregon, Texas, and the Carolinas, for example—hard-armor solutions are either not allowed at all or severely restricted. Many believe that such structures actually increase or accelerate beach erosion in the areas that are not directly protected by them, or at least that they disrupt the movement of sand and prevent the natural replenishment of adjacent beaches.
In some cases, too, although building a sea wall might protect the structures behind it, whatever sand that’s left in front of the wall can erode, leaving no beach to speak of—something highly undesirable in places where tourism dollars depend on sandy beaches, and downright illegal in places where the beach is considered public property.
Hawaii is now debating this issue. A bill before the legislature, awaiting the governor’s signature, would ease the standards for construction in coastal zones. Currently, private property owners along the coast can construct emergency structures like sea walls if erosion brings the ocean to within 20 feet of their home or other structure. Some planners are calling not only for a rejection of the current bill but also for revision of the earlier statute’s 20-foot rule, saying that both give preferential treatment to coastal property owners, allowing them to save their own buildings at the cost of the state’s sandy beaches. They cite a study that estimates 40% of Oahu’s coastline is now hard-armored, up from 7% 40 years ago.
Their suggested alternatives mainly involve zoning measures, such as banning construction of sea walls and similar structures except when they benefit public property such as harbors, as well as limiting further coastal development. They suggest more stringent review by coastal commissions of any proposed new development in sensitive or hazard-prone areas, but add that refusing to allow armoring for private property will discourage that development on its own.