is likely an over-estimation. There is also the potential for partial sedimentation on reef habitat with giant
kelp near Solana Beach totaling 1.05 acres, based on worst-case model predictions. Impacts at all these
locations would be less than significant because the surfgrass leaves would extend well above the predicted
sand deposition levels, allowing for long-term recovery, and the kelp is generally sparse and in non-
Borrow Sites
As with Alternative 1, the potential effects at borrow sites are described in terms of direct and indirect
impacts, plus dredge equipment.
Direct Impacts of Dredging
Alternative 2a would require about 330 acres of surface area for dredging or less than two percent of the
shelf habitat, however, because more material would be needed from borrow sites MB-1 and SS-1, the
depth of dredge would be one to three feet deeper at these locations. As discussed in the previous analysis
for Alternative 1a, the borrow sites would not be degraded as a result of the proposed action. Recovery
of the infauna appears to be rapid and undergoes a succession dependent upon grain size. Fish and
macroinvertebrates are plentiful and diversity appears to be enhanced within the excavated areas. While
abundances may be lower for some period, fish within the borrow excavations tend to be larger. Although
the presence of the borrow excavations would constitute a long-term alteration of benthic habitat with
impacts on species composition, the impact would not be significant. The impacted area would be relatively
small and the biota appears to recover quicker than the physical alterations.
Indirect Impacts of Dredging
All sensitive reef and kelp resources would have a 500-foot buffer, except at SO-7 where one artificial reef
would be 350 feet distant, so turbidity at those locations would not be greater than normalconditions. Even
with additional sand dredged from MB-1 and SS-1, the buffers would be retained and turbidity plumes
would be localized. These two sites in particular have high sand content and low silt levels with accordingly
small turbidity plumes.
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