Sand Dollars

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Sand Dollars
Federal Shore Protection Appropriations 1995-99
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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

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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

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Nourishment as 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

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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.

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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

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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.

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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

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Nourishment Needs