IV. Retreating Shorefines
265
In Virginia Beach, VA, beach nourishment is required each year and 28,999 m 3
(38,000 cu.yd) are placed on the beach at a cost of $1,5 million. A similar
solution has been suggested which would double the width of the beach, but it
requires huge expenditures to truck in 2 million m 3 (2,625,000 cu.yd) of sand.
Sea-walls have been prohibited in the State of Maine, and so have their close
relative the bulkhead ; North Carolina is following suit. The prohibition is an
effort to force better planning in coastal development and to halt interference
with the natural systems. In some case however, sea-walls have saved lives, as for
instance in Galveston, TX, but they have not solved the coastal erosion problem.
As they reflect the waves, they are in fact self-destructing. "The beach is
inherently a dynamic system and any attempt to make it stable by ... construction
of groins, sea-walls, bulkheads, and other engineering devices ... is ultimately
self-defeating.", said Acting Assistant Secretary of the Interior J. Craig Potter at
the Cities on the Beach conference, in 1986.
Other areas of the U.S.A. have already been mentioned (cf. 3.2.).
Successful restoration of the Sandy Hook Beach by nourishment has been
reported as well as in several locations on the southeast Atlantic and Gulf of
Mexico coasts (Huntington Island, SC, Cape Canaveral Beach, FL, Harrison
County, MS). Spectacular results were achieved at Key West, FL. where over a
405 mm (16 inch) laver of crushed limestone, a 203 mm (8 inch) blanket of sand
•
"~0
was deposited". Virginia Beach, VA fared less well and the problem has been
ascribed to the fact that the nourishment ("borrow") material was finer and not as
well sorted as was the original ("native") beach material.
In Key West gravel 8.35 mm (3/8 inch) in diameter (so-called "pea-sized") was
placed on the beach and gradually intermixed with fine sand during wave storms.
Groins existing, the area between them was filled to capacity immediately ; this
allows natural sand by-passing and continued deposition processes downdrift.
The coarser sand is more likely to resist storm-induced displacement.
In Georgia (USA) a combination of hard and soft counter-erosion measures was
taken. Tybee Island has a history of shifting shorelines and severe coastal
erosion 22. Groins, sea-walls and revetments have been built over the years,
however, more recently, beach nourishment was undertaken as an alternative and
complementary approach.
Beach nourishment was also undertaken further south at Hallandale, Florida. The
project was the subject of a thorough ecological impact study which showed that
seven years after the operation had been completed no ill effects on fish life could
be evidenced.
265
In Virginia Beach, VA, beach nourishment is required each year and 28,999 m 3
(38,000 cu.yd) are placed on the beach at a cost of $1,5 million. A similar
solution has been suggested which would double the width of the beach, but it
requires huge expenditures to truck in 2 million m 3 (2,625,000 cu.yd) of sand.
Sea-walls have been prohibited in the State of Maine, and so have their close
relative the bulkhead ; North Carolina is following suit. The prohibition is an
effort to force better planning in coastal development and to halt interference
with the natural systems. In some case however, sea-walls have saved lives, as for
instance in Galveston, TX, but they have not solved the coastal erosion problem.
As they reflect the waves, they are in fact self-destructing. "The beach is
inherently a dynamic system and any attempt to make it stable by ... construction
of groins, sea-walls, bulkheads, and other engineering devices ... is ultimately
self-defeating.", said Acting Assistant Secretary of the Interior J. Craig Potter at
the Cities on the Beach conference, in 1986.
Other areas of the U.S.A. have already been mentioned (cf. 3.2.).
Successful restoration of the Sandy Hook Beach by nourishment has been
reported as well as in several locations on the southeast Atlantic and Gulf of
Mexico coasts (Huntington Island, SC, Cape Canaveral Beach, FL, Harrison
County, MS). Spectacular results were achieved at Key West, FL. where over a
405 mm (16 inch) laver of crushed limestone, a 203 mm (8 inch) blanket of sand
•
"~0
was deposited". Virginia Beach, VA fared less well and the problem has been
ascribed to the fact that the nourishment ("borrow") material was finer and not as
well sorted as was the original ("native") beach material.
In Key West gravel 8.35 mm (3/8 inch) in diameter (so-called "pea-sized") was
placed on the beach and gradually intermixed with fine sand during wave storms.
Groins existing, the area between them was filled to capacity immediately ; this
allows natural sand by-passing and continued deposition processes downdrift.
The coarser sand is more likely to resist storm-induced displacement.
In Georgia (USA) a combination of hard and soft counter-erosion measures was
taken. Tybee Island has a history of shifting shorelines and severe coastal
erosion 22. Groins, sea-walls and revetments have been built over the years,
however, more recently, beach nourishment was undertaken as an alternative and
complementary approach.
Beach nourishment was also undertaken further south at Hallandale, Florida. The
project was the subject of a thorough ecological impact study which showed that
seven years after the operation had been completed no ill effects on fish life could
be evidenced.