Jun 04 2011

Beach Renourishment at Nags Head Forges Ahead

Published by under Student blog entries

Two weeks ago the beach renourishment program at Nags Head commenced and it is currently well underway. The plan seeks to reintroduce sand to a ten mile stretch of the beach, centered about Nags Head. Currently about 5.5% of the 4.6 million cubic yards of sand to be placed on the beach has been successfully deposited on the beach. The sand being deposited on the beach is currently withdrawn from an offshore site two miles south off the coast of Nags Head.

The renourishment program at Nags Head, like most other beach renourishment and dredging projects, is protecting the tourism treasure trove that is economically important to the Outer Banks. Tourists come to the Outer Banks for its wide and pristine beaches and its extensive amount of protected land, including the Nags Head Woods Preserve and Jockey’s Ridge.

^Beach Dredging, courtesy of Slurry Systems Marine

While renourishment does replace eroded sands to fortify beaches, it is important to take into account the potential environmental impacts of the project. It is likely that the site where sand is withdrawn will be negatively affected by the project. The site will suffer from increased water-borne sediment and nutrient concentrations, potentially resulting in the increase of photosynthesizing bacteria and decrease of dissolved oxygen content (DO) in the water column. This could make it more difficult for fish species to survive in the affected area.

One issue that I recently studied was the potential effects of ocean current energy generating technologies was the reduction of total wave power reaching the shore. This occurs because energy is conserved: as energy is being withdrawn by underwater turbines, etc., the amount of energy reaching the shore is diminished. Because less energy reaches the shore, there is less beach erosion, and less need for beach renourishment projects. While this would be an ideal situation, producing energy and sparing the Outer Banks from paying hefty prices for dredging, it is difficult to say what other potential problems could arise from the presence of an ocean current energy installation. This is primarily because there are so few test installations currently in place that are measuring environmental effects of an installation. One is Verdant, in New York’s East River, and more information can be found here.

In short, more study is needed to determine the potential local environmental effects of an ocean current energy installation.

Original Article: “USA: Nags Head Beach Renourishment Moves Ahead

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