Beach Nourishment and Protection (1995) / Chapter Skim
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3 The Federal Role in Beach Nourishment
3 The Federal Role in Beach Nourishment
Pages 58-81
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From page 58... ...
The USAGE's shore protection role is an extension of its longstanding civil works mission. In response to a request from the state of New Jersey for beach erosion control assistance in 1930, Congress enacted Public Law 71-520, which authorized the 58
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From page 59... ...
In turn, our ability to predict sediment behavior on beaches and therefore to design successful beach fill projects has improved considerably in the past two decades. The USACE conducts beach erosion control work under several different authorities.
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From page 60... ...
The USACE believes that nourishment is usually the most cost-effective way to reduce the threat of coastal storm damage and avoid the high costs of severe coastal storm damage. The design of federal shore protection projects by the USACE follows the concept of the optimization of net benefits accrued rather than a defense against storm hazards associated with a specific hazard benchmark.
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From page 61... ...
It went on to say: NOAA assists state efforts in coastal hazards planning and mitigation by working with the FEMA on post-hazard mitigation teams, and exercising its responsibilities with other federal agencies. Interagency Hazard Mitigation Teams identify and evaluate areas having significant hazards; review existing land-use regulations, building codes/construction standards, communications and utilities networks, and existing hazard-mitigation programs and authorities; recommend actions to prevent damage from future events; and coordinate actions to implement the team's recommendations.
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From page 62... ...
However, although 24 states and territories (90 percent of the participants in the Coastal Zone Management Plan) identified coastal hazards as a priority for coastal management enhancements, only two states reported on in the 1992-1993 CZMA biennial report include coastal engineering projects as part of their coastal management improvements.
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From page 63... ...
Additionally, storm wave energy is dissipated on the beach rather than on or in close proximity to the foundations of shorefront buildings. The dissipation of energy seaward of the construction setback lines also lessens the velocity of wave runup, which can attack building foundations.
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From page 64... ...
The technical basis for decision making on these issues is discussed below. The National Flood Insurance Program Program Overview The NFIP is both a financial protection and a hazard mitigation program.
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From page 65... ...
Detailed studies are conducted of coastal floodplains to identify base-flood elevations and to develop Flood Insurance Rate Maps (FIRMs)
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From page 66... ...
This practice does not accurately portray the damage risk to buildings because beach erosion can be episodic owing to meteorological cycles that may produce several years of stability followed by several years of stormy conditions that dramatically alter the beach geometry. Thus, the mapping could provide estimates of risk that are either too large or too small.
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From page 67... ...
Congress, in examining possible refinements to the NFIP, expressed concern that credit was not given to the diminishment of coastal hazards and the reduction or elimination of historic erosion trends as a result of beach nourishment programs. On September 23, 1994, President Clinton signed into law the Riegle Community Development and Regulatory Improvement Act of 1994 (P.L.
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From page 68... ...
The options for addressing beach nourishment projects in the NFIP range from no official recognition through intermediate measures (e.g., requiring nourishment projects as a precondition for issuance of insurance and economic incentives to sustain and maintain projects' to ultimately reduce insurance premiums and constructions standards. In the latter case, a related question is whether any cost savings by reducing insurance premiums or constructions standards should be applied to further hazard mitigation measures or whether the savings should be passed directly to owners of protected properties for discretionary use.
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From page 69... ...
Specific issues addressed include pollution and waste disposal, fragile environments, marine reserves and biological habitats, and geological records of environmental change. Natural hazards and public safety research is conducted to better understand the frequency and distribution of catastrophic events and the geological processes acting in the affected coastal regions.
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From page 70... ...
Results of these studies are finding immediate application in the design of coastal restoration projects by the Wetlands Task Force. THE MINERALS MANAGEMENT SERVICE As economical offshore sand and gravel deposits suitable for beach nourishment become harder to locate, sources beyond state waters become more attractive.
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From page 71... ...
With increasing demand for suitable sand and diminishing nearshore resources, the MMS is working cooperatively with 10 Atlantic and Gulf coast states on projects to identify and assess OCS sand resources for coastal restoration and shore protection needs (see, for example, Conkwright and Cast, 1994~. An MMS study of particular interest to the beach nourishment topic is "Wave Climate Modeling and Evaluation Relative to Sand Mining on Ship Shoal, Offshore Louisiana." This study, awarded in July 1994, is using numerical modeling to examine the current and wave fields around Ship Shoal, an offshore geological feature located in the central Gulf of Mexico, adjacent to Louisiana barrier islands.
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From page 72... ...
Construction setback lines, erosion rate based or otherwise, have been established in some states in an effort to reduce damage in areas subjected to shoreline retreat. Destruction of dunes and conversion of beaches for development eliminate or reduce the natural storm and erosion protective benefits that an entire coastal community relies on during periods of high tides, storm surges (on the Atlantic and Gulf coasts)
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From page 73... ...
That program is primarily concerned with the base-flood elevation and the associated effects of wave runup and wave height in the coastal hazard zone insofar as these forces threaten individual buildings. The differences between the two programs need to be understood in order to relate the performance of beach nourishment projects to FEMA's objectives for mitigation of coastal hazards.
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From page 74... ...
Nevertheless, the presence of an effectively designed and maintained beach nourishment project for such a storm can increase the level of protection within the coastal hazard zones mapped by FEMA in one or more of the following ways: · by preventing waves or wave runup from reaching the V zone, · by reducing wave runup in the V zone, · by reducing the height of waves that reach into V zones as a result of episodic erosion or because of high flood elevations, and · by providing a buffer between the open ocean and the V zone on existing maps. The actual reduction of risk provided by the beach fill varies considerably over the life of the nourishment project as the advanced-fill dimensions are reduced through erosion.
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From page 75... ...
; basing construction standards? premium rates, or both on the determined median fill dimension that would provide a median risk reduction potential over the project life; establishing the alternatives of an option for a beach nourishment program as a precondition for the issuance or continuation of flood insurance or the setting of higher insurance rates; maintaining construction standards and premium rates at levels appropriate to base-flood elevations determined prior to beach nourishment; · evaluating protective benefits of beach nourishment programs, maintaining rates, and allocating any savings to funding at the local, regional, or national levels for coastal hazard mitigation projects; · providing grants or funding to design nourishment projects, conduct sitespecific erosion analyses, or monitor project performance; · establishing a federal entity to provide technical assistance to states or
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From page 76... ...
Unlike commercial insurance, the federal government relies on premiums to fund the basic flood insurance program rather than on earnings from invested premiums. When owners' contributions to flood insurance are reduced, the reduction could be considered a subsidy because there are few economic incentives for owners to invest construction cost or insurance premium savings in further coastal hazard mitiga tion measures.
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From page 77... ...
Relaxation of construction standards in response to hazard mitigation benefits of uncertain duration could potentially undermine the NFIP's leverage to hold communities accountable for sound floodplain management practices and property owners accountable for construction that reduces risk. With respect to the argument that reducing construction standards could serve as an incentive for maintenance of a beach nourishment project, the fact that beach nourishment projects and flood insurance serve different objectives must be considered.
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From page 78... ...
Stabilization or progradation of the shoreline through nourishment of the beach could potentially move the setback line or the reference feature farther seaward following nourishment unless their locations were fixed at the prenourishment project locations. Premium Rate Adjustments An alternative to lowering construction or zoning standards is a reduction in flood insurance premium rates.
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From page 79... ...
Given the uniqueness of each beach community, the answer may lie in the development of comprehensive beach erosion and hazard mitigation management plans for discrete reaches of the shoreline. A comprehensive plan for a beach town or a region encompassing a geomorphic or littoral compartment could include improved construction standards, removal of some or all dwellings from particularly hazardous locations, and the use of beach nourishment to reduce the hazard potential.
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From page 80... ...
high-erosion-risk zones; no remapping of hazard areas; · no reduction in construction standards as they pertain to shore protection; · a dedicated funding commitment for the life of the program for all planned and emergency renourishments; a requirement that sand sources be available and dedicated (including sand rights) to the program for initial placement, all planned renour~shment, and a reasonable number of contingency replenishments; a requirement for alternate or secondary sources of sand should physical conditions reduce sand from sources that are dedicated to the program; · a requirement for a contingency plan that would restore an adequate design level of protection for the subaerial beach following storm losses; · a requirement for a program to perform as designed within some acceptable level of uncertainty; and · a requirement for long-term monitoring with dedicated funding covering the full program.
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From page 81... ...
1994. Shoreline Protection and Beach Nourishment Projects of the U.S.
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