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City of Solana Beach
Section 2
Shoreline and Coastal Bluff Management Strategies Draft MEIR
Project Description
Reef width of 320 feet
Offshore slope of 1:20 (vertical:horizontal) to enhance the surf break
Shelf elevation ranges from 2 feet MLLW to +1 feet MLLW
Groin Field
Groins are long, narrow structures placed approximately perpendicular to the shoreline
to build or widen a beach by trapping littoral drift. The widened beach can then serve
recreational and shore protection functions. Groins are fundamentally different from
breakwaters and artificial reefs in that they do not attempt to modify transmitted wave
energy as a mechanism for reducing long shore sediment transport, but instead they
directly block the currents that carry the suspended sediment along the coast. Groins
and groin fields have been used successfully to retain sand throughout the world and are
recognized coastal engineering structures.
A typical groin field design would include (SANDAG 2001b):
Length of 930 feet
Two groins spaced 1,500 feet apart
Maximum fillet width of 280 feet
Minimum beach width of 150 feet between groins
Total retained beach area of 750,000 square feet (about 17 acres)
Structure crest elevation of +14 feet MLLW at the beach berm, sloping down to +3
feet MLLW in the water
Sand-filled geotextile bags or removable sheet-piles could be used for a temporary
pilot structure or armor stone for a permanent structure. Armor stone is assumed for
the cost analysis.
2.3.2 Intensity
The exact number of periodic beach fills over a 50-year or 100-year period is difficult to predict
according to SANDAG. This is due to the limited data that exists on beachfill longevity, the
stability of the fill affected by future wave climate can be highly variable, and the future
frequency and volume of future regional beach fills is unclear (SANDAG 2001b). In June 2001,
146,000 cubic yards of sand was pumped onto the Fletcher Cove beach as part of a SANDAG
regional sand replenishment project, which placed 1.8 million cubic yards on ten beaches in
North County. Sand Replenishment structures such as breakwaters, reefs, and groins would
typically be constructed once every 50 years.
2.3.3 Location
All of the possible future subsequent sand replenishment projects would probably be mobilized
at Fletcher Cove (south end). Sand could then be distributed north and south depending on
environmental constraints. Constraints to sand retention exist along the region's coast due to
sensitive environmental resources and existing surfing locations. Solana Beach is moderately
Project No. 323530000
Page 2-26






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