Some areas are constantly in danger during severe storms. Coastal restorationĮven with the implementation of coastal shoreline erosion and risk reduction measures, residual risk remains. For instance, non-structural shore protection methods that have the potential to control erosion include stabilizing dunes with fences and/or native vegetation, wetland protection and restoration, and relocation or removal of structures and debris. Army Corps of Engineers has re-emphasized the need to consider a whole range of solutions to coastal erosion, not only structural solutions. USACE also offers a well illustrated booklet, How Beach Nourishment Projects Work. Army Corps of Engineers (USACE) is authorized to carry out beach nourishment for shoreline protection: their Beach Nourishment site describes the benefits of adding sand to beaches. Nonetheless, many communities still practice beach nourishment. When completed in 2017, the beach was 60 feet wide and sloped up to 5 feet above mean low water. The sand is part of a $34.5 million project to reduce storm damage risk to infrastructure along a 7.3 mile stretch of waterfront. Army Corps of Engineers’ contractors pump sand dredged from the bottom of the Chesapeake Bay up to Norfolk, Virginia’s Ocean View Beach. Some communities bring in huge volumes of sand repeatedly, only to see it wash out to sea in the next season's storms. Beach nourishment is also expensive: check the Beach Nourishment Viewer to explore details about sand placement efforts for more than 2,000 beach nourishment projects since 1923. Adding sand to a beach does not guarantee that it will stay there. Consequently, these projects must comply with a wide range of complex laws and regulations. However, beach nourishment has also become a controversial shore protection measure, in part because it has the potential to adversely impact a variety of natural resources. One common strategy for dealing with coastal erosion is beach nourishment-placing additional sand on a beach to serve as a buffer against erosion or to enhance the recreational value of the beach. Unlike structural projects, nature-based or "green infrastructure" protection measures enhance the natural ability of shorelines to absorb and dissipate storm energy without interfering with natural coastal processes. Many states have shifted toward non-structural shoreline stabilization techniques. Additional reasons to avoid structural protective measures include the high costs to install and maintain them, state or local prohibitions against them, their propensity to cause erosion to adjacent beaches and dunes, and the unintended diversion of stormwater and waves onto other properties. 4 Structural projects interfere with natural water currents and prevent sand from shifting along coastlines. As understanding of natural shoreline function improves, there is a growing acceptance that structural solutions may cause more problems than they solve. In the past, protecting the coast often meant "hardening" the shoreline with structures such as seawalls, groins, rip-rap, and levees. Taken on June 20, 2008, the photo on the right shows what often follows such undercutting: chunks of coastline tumbling into the sea. Grassy turf extends out over a wave-cut notch. Taken on August 9, 2007, the photo on the left shows how ocean waves have undercut the land nearest the shore. These photos show an area near Drew Point, along Alaska's northern coast. Information is also available on various forms of Storm-Induced Coastal Change. Geological Survey's Coastal Change Hazards Portal offers a Coastal Vulnerability Index that can help identify locations where coastal erosion may occur along undeveloped coastlines. Increases in storm frequency and intensity in the future will also cause increased coastal erosion. If we let the shoreline migrate naturally, we can expect to see erosion rates increase, especially in regions of the coast that are already dealing with starved sediment budgets and rapid shoreline migration. If we choose to build hard structures in an attempt to keep the shoreline position stable, we will lose beach area due to scour. Sea level rise will cause an increase in coastal erosion and the human response will be critical. In undeveloped areas, these high recession rates are not likely to cause significant concern, but in heavily populated locations, one or two feet of coastal erosion may be considered catastrophic. Severe storms can remove wide beaches, along with substantial dunes, in a single event. Average coastline recession rates of 25 feet per year are not uncommon on some barrier islands in the Southeast, and rates of 50 feet per year have occurred along the Great Lakes. While coastal erosion affects all regions of the United States, erosion rates and potential impacts are highly localized. Cliff erosion is a common storm-induced hazard along the West Coast.
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