2.0 Alternatives Considered
Beach, Cardiff, portions of Del Mar, Torrey Pines, Mission Beach, and portions of Imperial Beach. At
locations with existing shore protection (revetment or seawalls), the line would be placed along the toe of
the protective device. Sites with shore protection include South Oceanside, portions of North Carlsbad,
Leucadia, Del Mar, and portions of Imperial Beach. At locations with bluffs behind the beach, the
discharge line would lie along the bluff toe. Beaches backed by bluffs include North Carlsbad, South
Carlsbad, Leucadia, Solana Beach, and Torrey Pines.
The discharge line would be placed on top of the existing sand or cobbles and be buried at intervals to
provide for pipe anchoring and for beach access to the public. Areas of active construction, i.e., where
sand is being emitted from the pipe and redistributed by earthmoving equipment, would be cordoned off
from the public with signs. Construction crews would also be onsite to monitor the construction site to
prohibit public access. All other areas of the discharge line would be open to public use.
Maintenance of the discharge line would occur as necessary. The line may be affected by waves and tides
and may periodically require added support, protection, or relocation. Earthmoving equipment and cranes
may be used to maintain the line. Figures 2-21 and 2-22 show photographs of the dredge discharge line
from a previous beach replenishment project at South Carlsbad State Beach (Ponto) to illustrate a recent
example of this type of operation.
More frequent line maintenance may be required along areas with a narrow existing beach backed by
bluffs such as South Carlsbad, Leucadia, Solana Beach, and Torrey Pines. Little room exists for line
placement and protection at these sites. The line may be more exposed to waves and may be affected
during high tides or waves. However, the intent of maintenance is to provide safety and security for these
temporary features.
Training Dikes
Training dikes would be constructed to reduce turbidity and aid inthe retentionofpumped sand at receiving
beaches. The material coming from the dredge material discharge pipeline is a slurry mix of sand and
water. Once the water flows back to the ocean the heavier sand settles onto the beach. The training dike
system consist of two dikes one that is perpendicular to the beach connected to one that is parallel to the
beach, forming an "L" with the long end parallel to shore. The dikes would be constructed using two
bulldozers. Sand would be placed at a single discharge point behind (i.e., landward) the dikes. The dikes
would be used to direct the flow of the discharge and slow down the water flow thereby allowing more
sediment to settle onto the beach instead of washing back into the surf zone. Where sand is not
Page 2-42
Regional Beach Sand Project EIR/EA
99-69\SANDAG EIREA 3.4.wpd 7/17/00
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