down when placed on the barge. A crane was attached to the inverted legs and the unit
was lifted off the barge and placed on the bottom. Divers assisted in the alignment and
interlocking as the units were placed on the seabed. Surveys of cell 6 in March and June
2002 indicated that the 2.7 m NAVD contour straight and parallel to the shoreline near
the seaward end of the groins and did not change over time. No excavation or fill was
needed to place these units and no filter cloth was used as a base. With a length about
three times that of the Beachsaver Reef units, only 22 units were needed to span the
200 m of the cell. It only took four working days to complete this installation between 26
September and 2 October 2002.
OBJECTIVES
This location at Cape May Point is somewhat unique in that strong flood tidal
currents just seaward of the existing groins play an important role in the movement of
sand along this beach. Waves, approaching the beach from a range of 180 degrees from
east to west, also have an influence on sand transport, with the larger waves approaching
from the east to south quadrant of the open Atlantic Ocean. The combination of the
waves and flood tidal currents produce a net longshore current from east to west and has
resulted in erosion of sand from the groin compartments. The primary objectives of this
Demonstration Project are therefore 1) to evaluate effectiveness of the various nearshore
submerged structures in retaining sand on the beach, as compared with unprotected groin
compartments, 2) compare the effectiveness of the more costly Beachsaver Reef with
the less expensive Double-T submerged sill and 3) as a long-term objective to evaluate if
theses various structures lengthen the time between periodic renourishments for the
proposed Cape May Meadows to Cape May Point beach fill project scheduled for
construction in 2004.
Initial monitoring of the project over the first year will focus on comparing
retention of native sand behind the new Beachsaver Reef (cell 5) with that behind the
Double-T sill (cell 6). Monitoring will also examine the behavior of the remaining
advanced fill placed in cells 3 and 4 in December 2000 to evaluate the effectiveness of
the initial 1994 Beachsaver Reef installation in cell 3 in reducing loss of sand from the
beach relative to the open groin compartment (cell 4). The other cells (cell 1, 2, 7 and 8)
will be also be monitored to evaluate relative beach change in the absence of sand fill for
the various structure and control configurations. The Lower Cape May Meadows to Cape
May Point Federal Project is expected to go to construction (subject to funding)
following the first year of monitoring. The Federal project includes beachfill in all cells
within the Cape May Point Demonstration Project area. After construction of the Federal
project, monitoring of the Demonstration Project will focus on effectiveness of the
Beachsaver Reefs and the submerged Double-T sill in retaining beachfill and reducing
renourishment requirements for the Federal project.
Monitoring Plan
The goal of this study is to monitor the project performance for three years and
assess the sand trapping capabilities of each type of structure. The Beachsaver Reef is
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