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Sand Dollars

Sand Dollars. Federal Shore Protection Appropriations 1995-99. Nourishment . Rebuild the beach and dune system. Mimic the historic position and shape of the shoreline Add sand (gravel) in sufficient quantities to “push” the shoreline in a seaward direction

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Sand Dollars

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  1. Sand Dollars Federal Shore Protection Appropriations 1995-99

  2. Nourishment • Rebuild the beach and dune system. Mimic the historic position and shape of the shoreline • Add sand (gravel) in sufficient quantities to “push” the shoreline in a seaward direction • USACE adds 1.1 - 1.3 cy/ft of shoreline. Assumes the beach ends in - 28ft (closure depth). Extends from + 7ft to - 28ft. • Volume depends upon compatibility of the source material

  3. Beach Nourishment • Requires large volume of beach-quality material- hundreds of thousands of m3/km (million cy/mile) • Periodic maintenance (3 - 4 yrs) • Storms will necessitate more frequent renourishment • Best to nourish long sections of shoreline

  4. Nourishmentas a Multi Purpose Management Tool • Hard Structures generate adverse effects in near and far fields • Soft structures such as nourishment is an environmentally “acceptable” method of preserving and maintaining the oceanfront beaches • provides storm protection • mitigates long term erosion • increases recreation potential

  5. Sources of Sand • Terrestrial sources- coastal dunes, coastal plain, rivers, inland sand dunes, and spoil islands (upland disposal sites) • Offshore sources- dredge spoils from harbors, inlets (flood and ebb deltas), estuarine channels, sand fields, ridges, paleo-channels, and poorly lithified rock units.

  6. Costs • Function of proximity of borrow source to placement site & size of project • Inland sites (US) costs range from $10 - $80/cy • Offshore sites range from $ 3- $ 20+/cy • Some beaches nourished with sand barged in from great distances - Japan (Taiwan) and Barbados (Cuba). Costs reach hundreds of USD/cy • Netherlands- sand far offshore

  7. Costs- Who Pays? • Public Beaches - Fed. Govt. pays 65 %, State, County, & Towns pay 35 %. • Private Beaches- Like Figure 8 Island -100%. • For projects other than nourishment, ie., navigation improvements -- the “locals” may have to pay for placing sand on beach. Pay difference in the cost for pumping etc., from original disposal site to the beach placement site. • Cost sharing equation will change.

  8. Beach Nourishment • Although accepted as the most viable means of managing the eroding beach-- many problems • Engineering project design • Environmental degradation • Economic considerations • Availability of Sand for beachfill • Social and Political ramifications

  9. Nourishment Needs

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