Full document / COSOC-W-86-002 - the National Sea Grant Library

Estuarine andCoastal Management -Toolsof theTrade.
Proceedings ofthe Tenth National Conference ofThe
Coastal Society. October 12-15,1986. New
Orleans. LA. Copyright by TheCoastalSociety
1987.
BARRIER ISLAND RECONSTRUCTION: BRIDGING
THE GAP BETWEEN ACADEMIC RESEARCH AND
ENGINEERING PRACTICES
Roberts. Jones
Terrebonne ParishConsolidated Government
P.O. Box 2768
Houma. LA 70361
Introduction
TVJrr3on"ne"~parish is losing vast areas of wetlands and barrier Islands.
Over a 23 year period of time, from 19S5 to 1978, Terrebonne Parish lost
42% of its barrier islands (Wicker, I960). In 1985, during Hurricane
Juan, Terrebonne's Eastern Isle Derniers lost 10 - 20% of its land area
(Penland, 1986). Ihese islands are considered to be a key elanent in the
short term survival of Tarrebonne's wetlands, if the islands are lost,
it is estimated that Terrebonne's land loss would accelerate
geometrically. Shoreline erosion rates for these islands typically aver
age 34 feet per year (Meyer-Arendt, 1982). Terrebonne's islands suffer
much of their damange during severe winter storms or hurricanes. Normal
tidal and wave action is mild and works to restore the islands (Mossa,
1985). This restoration is hindered by lack of sand lost in breaches and
overwashes which occur during the winter storms and hurricanes.
With the disapperance of its islands and its severe land loss problens,
Terrebonne began to seek ways to stabilize its coastline. If not
stabilize, then at least extend the life of its islands and wetlands.
Immediately a debate broke out in Terrebonne Parish, which mirrors the
national debate of soft (natural) defense versus hard (structural)
defenses. In 1982 a report prepared by consultants hired by the Parish
concluded! "Shoreline erosion can be retarded by nourishing the beaches
with introduced course sediments, and the loss of sand can be reduced by
sealing off breaches and washovers and installing sand-trapping jetties
in locations where longshore migrating sand enters major sink areas
(Wicker, 1980). Debate in Terrebonne raged on. Two searches were
initiated at this timet one for funds and the other for information.
By 1983 it was determined that: a) a preponderance of information
available suggested that soft or natural coastal defenses were more cost
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