Geologists: Seawalls Are Killing Beaches

The world's beaches are disappearing, write the authors of 'The Last Beach.' Maybe someone ought to tell Israeli officials.

Itzik Ben-Malki

The world’s beaches are disappearing, as much due to rising sea levels as to seaside development and the seawalls intended to protect those new buildings from the encroaching shoreline, say geologists Orrin H. Pilkey and J. Andrew G. Cooper, the authors of the recently released book “The Last Beach.”

Perhaps copies of this book, published by Duke University Press, should have been distributed to the National Council for Planning and Building subcommittee due to meet next week to discuss objections to a seawall construction plan.

The plan calls for the seawalls and other shorelines structures to be built near cliffs in the Herzliya and Netanya areas that are in danger of collapsing.

Proponents of the plan say it is meant to prevent damage to the landscape and protect the beaches — and the buildings on it — from massive erosion and winter storms.

However, Pilkey, a professor emeritus of geology at Duke’s Nicholas School of the Environment, and Cooper, a professor of coastal studies at the University of Ulster’s School of Environmental Sciences, say seawalls and other coastal defense structures have been shown to seriously damage the beaches around the world where such methods are used, and require constant rebuilding at increased cost.

“[T]he rush of civilization to the shore that we have witnessed in our lifetime has been quite unlike anything that occurred in the past,” write Pilkey and Cooper. “Thousands upon thousands of buildings, some many stories high, are arrayed along beaches that we know are retreating toward them. We know the retreat will continue and will become more rapid as sea-level rise continues. Beachfront buildings sooner or later will be threatened with undermining and will collapse.”

In many cases the coastal defenses are intended protect real estate. The higher the property’s value, the greater the owners’ pressure to fortify the beach adjacent to it, the authors write. The beach must not be sacrificed for this purpose, they say, adding that in any case such action often does little but delay the rise in sea level that will eventually overcome any defenses.

“Yet trying to stop shoreline retreat in the face of rising sea level destroys the beach, and the beach is why we rushed to the shore in the first place and took up residence there. We are killing the goose that laid the golden egg!” they write, adding: “As geologists, we are bewildered by this ridiculous and obviously wrong state of affairs.”

Throughout the book, the authors refute the assumption that coastal defenses allow the effects of a rising sea level can be assessed in advance.

They also say cliff erosion actually provides the sand necessary for adjacent beaches to survive, and that dunes and wide beaches protect buildings from storms better than seawalls do.

In some cases the local authorities in Israel artificially supplied sand to beaches whose sand dwindled due to the construction of breakwaters and quays in nearby areas. Pilkey and Cooper say this method is preferable to building seawalls and sea dikes. But artificial sand supply is extremely expensive and has dire environmental repercussions on the sea floor from which it is taken, they say. Also, it encourages real estate projects near the shores, because it gives the impression that the beaches are protected, they say.

Pilkey and Cooper suggest an alternative approach. We must recognize the fact that beaches undergo a dynamic process of destruction and renewal. In the process they provide human beings with the experience of a dynamic ecosystem, as well as being a habitat for flora and fauna. Instead of continuing to engineer the beaches — and by so doing destroy them — we should avoid building walls and barriers, refrain from construction near the shore line and evacuate existing structures. Many buildings will have to be evacuated in any case once the sea level rises.

Some countries already put this policy into practice. The British conservation organization National Trust decided two decades ago to return beaches to their natural state.