USA: Rebuilt wetlands can protect shorelines better than walls
By Rowan Jacobsen
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[A study by Rachel K. Gittman, a researcher at the University of North Carolina,] confirmed what many experts had begun to suspect. “Armored” shorelines such as bulkheads offer less protection against big storms than people think. By reflecting wave energy instead of dispersing it, they tend to wear away at the base, which causes them to gradually tilt seaward. Although they still function well in typical storms, they often backfire when high storm surges overtop them, causing them to breach or collapse, releasing an entire backyard into the sea.
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In recent years more scientists and policy makers have come to believe that “living shorelines”—natural communities of salt marsh, mangrove, oyster reef, beach and coral reef—can be surprisingly effective in a battle coastal residents have been losing for years. U.S. shores are disintegrating as higher seas, stronger storms and runaway development trigger an epidemic of erosion and flood damage. Every day waves bite off another 89 hectares of the country. Every year another $500 million of property disappears. Overall, some 40 percent of the U.S. coastline is suffering ongoing erosion.
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Coastal restoration may finally be getting the attention it deserves. “Things are really beginning to change,” [says Michael W. Beck, a research professor at the University of California, Santa Cruz]. The Army Corps, which for decades has favored hardscape solutions, has launched an Engineering With Nature initiative—something many planners thought they would never see. The National Oceanic and Atmospheric Administration has made living shorelines a centerpiece of its coastal-resilience blueprint. Hundreds of projects have been completed or are underway around the country, ranging from shoreline stabilizations in Maryland to bulkhead removal in Puget Sound. Most are small, community-based efforts, but larger ventures are becoming more common.
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