278
R.H. Charlier and Chr. P. De Meyer
Some applications in the U.S.A. have lead to the conclusion that the waterdepth
is critical for the location of a feeder berm. Successful applications have been
done in Morocco (Agadir) and the U.S.A. (Mobile Harbor, Southern Long
Island).
More recently, a feeder berm has been installed at De Haan (Belgium) in
conjunction with a profile nourishment (cf. 3.2.10) 36.
3.6
Beachbuilder and Beach Saver
Beachbuilder is a new beach preservation system based on the premise that it is
better to utilize erosive wave energy than to dissipate it. The system builds up a
beach : a thin flexible flow control sheet of rugged elastomer - coated polyester,
or nylon fabric. It is tethered in place over a portion of the surf- zone surface. The
surf rushes beneath it while scouring the bottom surface, transporting loosened
sand particles towards shore and into the beach.
As the backwash passes above the weighted sheet, resting on the bottom,
underlaying trapped sand particles remain undisturbed. Sand built-up during
winter provides an improved beach during the tourism season. Costs are
supposed to be less than those of artificial nourishment. However, only tanktests
have been conducted (Beardsley, 1993) but, perhaps the system could be a
supplementary technique in beach nourishment schemes 35.
Besides Beardsley's Beachbuilder, another device called Beachsaver has been
developed by New Jersey based Breakwaters International Inc. It involves hard
structures but is taken up here because it claims to be a complementary method to
beach nourishment 35.
In this approach to erosion control, a curtain of water is created suspending sand
over the beach as offshore current below channels through the backwash flume.
Suspended sand is carried black onshore by incoming waves. 'Reefs" are placed
in the surf zone at depths of approximately 2 m (606 ft) below mean low tide, run
roughly 300 m (984 ft). Surf and beach profiles determine the precise siting of +
100 (21 ton) interlocking reinforced concrete triangular modules 3 by 5 by 2 m
(9.84 fi length x 16.4 ft width x 6.6 ft height). Less sand has to be placed on a
beach as the beachsaver keeps it nearshore and maintains it in place impeding its
return to the sea during replenishment. The reef's slope deflects wave energy,
allows sand to wash onshore, while its angled grooves enhance sand collection at
the base. On the inland side of the module, a three slotted opening flume projects
a water curtain inhibiting sea-ward sand movement.
R.H. Charlier and Chr. P. De Meyer
Some applications in the U.S.A. have lead to the conclusion that the waterdepth
is critical for the location of a feeder berm. Successful applications have been
done in Morocco (Agadir) and the U.S.A. (Mobile Harbor, Southern Long
Island).
More recently, a feeder berm has been installed at De Haan (Belgium) in
conjunction with a profile nourishment (cf. 3.2.10) 36.
3.6
Beachbuilder and Beach Saver
Beachbuilder is a new beach preservation system based on the premise that it is
better to utilize erosive wave energy than to dissipate it. The system builds up a
beach : a thin flexible flow control sheet of rugged elastomer - coated polyester,
or nylon fabric. It is tethered in place over a portion of the surf- zone surface. The
surf rushes beneath it while scouring the bottom surface, transporting loosened
sand particles towards shore and into the beach.
As the backwash passes above the weighted sheet, resting on the bottom,
underlaying trapped sand particles remain undisturbed. Sand built-up during
winter provides an improved beach during the tourism season. Costs are
supposed to be less than those of artificial nourishment. However, only tanktests
have been conducted (Beardsley, 1993) but, perhaps the system could be a
supplementary technique in beach nourishment schemes 35.
Besides Beardsley's Beachbuilder, another device called Beachsaver has been
developed by New Jersey based Breakwaters International Inc. It involves hard
structures but is taken up here because it claims to be a complementary method to
beach nourishment 35.
In this approach to erosion control, a curtain of water is created suspending sand
over the beach as offshore current below channels through the backwash flume.
Suspended sand is carried black onshore by incoming waves. 'Reefs" are placed
in the surf zone at depths of approximately 2 m (606 ft) below mean low tide, run
roughly 300 m (984 ft). Surf and beach profiles determine the precise siting of +
100 (21 ton) interlocking reinforced concrete triangular modules 3 by 5 by 2 m
(9.84 fi length x 16.4 ft width x 6.6 ft height). Less sand has to be placed on a
beach as the beachsaver keeps it nearshore and maintains it in place impeding its
return to the sea during replenishment. The reef's slope deflects wave energy,
allows sand to wash onshore, while its angled grooves enhance sand collection at
the base. On the inland side of the module, a three slotted opening flume projects
a water curtain inhibiting sea-ward sand movement.