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Seaworthy Solution is Turning the Tide on Beach Erosion Off the Israeli coast, now submerged, King Herod's Harbor is still considered by many historians to be one of the greatest feats of coastal engineering in the history of mankind, an eighth wonder of the world, comparable to landing a man on the moon. Yet, Matthew tells no parable of the artificial harbor at Caesarea Maritima (Sebastos): the archaelogic record details the innovations. More than 2,000 years ago, Herod's engineers constructed a 200,000-square-foot harbor--one of the four largest Mediterranean harbors of its time--in less than a decade, despite the fact that no harbor had ever been built without incorporating coastal island bays or other natural features into the design. The king's builders used rocks and hydraulic concrete (which hardens underwater) for two breakwaters, first laying foundations of rubble on the ocean floor. As wave action shifted and consolidated this material, marine growth solidified the structures against undercutting by heavy seas. To offset the known pattern of erosion and siltation that beset harbors in the eastern Mediterranean, they also modified the main breakwater with sluices and channels to capture sand-free water from the wave crests for periodic use in flushing silt deposits back out through the mouth of the harbor; a secondary breakwater dissipated the impact of waves. Likewise, no parable of Matthew's tells of the coastal erosion that results when structures that project from the shore interfere with natural water dynamics and beach-building process of the ocean. But the success of Herod's example has led harbor engineers to repeat practices lead to shoreline degradation. And, that is a story that is only beginning to be told . . . by Dick Holmberg of Erosion Control Systems, Inc. By virtue of a long maritime career, the originator of beach stabilization technology, that rebuilds beaches by harnessing ocean action as a constructive force, has studied many shores firsthand and cites both historic and recent geologic records of beach erosion that has resulted from repeating intrusive engineering practices on an broad scale. Observing that "In the 1800's, St. Joe's and Michigan City Harbors were so affected by sand carried by off-shore currents that they did not survive," Holmberg points to photographic records of "rivers of sand" that similarly plague modern ports, like Manistee Harbor, MI (shown above). In fact, in the last 150 years, local port authorities have resorted to maintaining harbors and beaches along the east and west coasts of the U.S. by dredging and trucking in sand on a periodic basis, otherwise unable to stem the marauding tide. The tide is like a thief in the night, robbing the beach of its volume, stability, and aesthetics, not to mention is real property value: o Real estate value is devalued by unsuccessful attempts to salvage coasts with rip-rap, and sometimes destroyed to minus-zero value (New Buffalo, MI) o Loss of community leaders who ("unable to sell at any price") investments o Affiliated drains on the local community economy In hopes of avoiding the fate of King Herod's Harbor, beachfront property owners on both U.S. coasts and the shores of the Great Lakes are turning to technology for help. Reference New Buffalo, MI--whose shoreline nearly collapsed, threatening to take million-dollar homes with it, in 1983--is booming ten years after Holmberg's Underwater Stabilizer System tm was installed, as are 100 other restored Michigan beaches. Holmberg's solution is an interlocked system of long, concrete-filled geotextile bags, installed in 10-20 feet of water--often rough water at the base of cliffs, which dissipate the impact of waves. The "arms" of the stabilizing unit encourage waves and currents to drop sand which "accretes" into new beach, eventually expanding the beach profile into a gently sloping shore. Holmberg says the system utilizes the ocean's own dynamics to carry sand from offshore deposits back to degraded beaches, and the success of each restoration expands not only that beach, but the collective benefit to adjacent shores. Holmberg directs Doubting Thomases to reference the Western Michigan University Great Lakes Coastal Research Program report ("Orchard Beach Park Demonstration Project 'Undercurrent Stabilizer System tm Shore Stabilization/Accretion Program Interim Report on the 1993-1994 Surveys") which concludes: "Consistent profile gain . . . and significant foreshore/backshore ('beach') accretion with no apparent negative impact down drift must be viewed as a 'success' in almost any context." While beach nourishment advocates may argue that non-mechanical means are preferred, there has to be a beach to nourish. Holmberg is quick to note natural beach nourishment occurs as a result of his stabilizing system: "Beaches provide natural filtration and detoxification by exposure to ultraviolet light, and microscopic organisms on shore are filters, too." The armadas of change may have to navigate bureaucracy for some time before the technology is used proactively, but Holmberg's technology is not just a restoration strategy. No doubt Landscape Architects and erosion control specialists foresee the technology's potential for preventing erosion . . . or developing a beach where none exists. Picture the look on a resort owner or developer's face when you tell him that the beach could be expanded . . . to accommodate twice as many patrons . . . . LASN

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June 18, 2019, 6:42 pm PDT

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