Executive Summary
Table ES-7
Summary of Environmental Consequences
Alternative 1
Alternative 2
No Action
GEOLOGY AND SOILS
Alternative 1a. After placement of sand onto a receiver site, the
Alternative 2a. Under this alternative, nine receiver sites would
No significant impacts would occur to geology
existing beach area north and south of the receiver site would widen
receive sand. At these receiver sites, impacts would be similar
and soils; however, the receiver beaches would
as a result of longshore and cross-shore spreading. No long-term
for those described for Alternative 1. The same borrow sites
continue to erode undeterred by the
significant impacts to coastal geology are anticipated due to
would be used under this alternative but at different quantities.
replenishment project and the project benefits
sediment transport or the increased sediment thickness at the
However, no significant impacts are anticipated.
would not occur.
existing, seasonal offshore bar. No significant geology and soils
impacts are anticipated to occur to the dredge borrow sites with
Alternative 2b. This alternative would not change the impact
implementation of Alternative 1.
analysis described above for Alternative 2a.
Alternative 1b. Impacts would be less than significant and no
mitigation measures would be necessary.
COASTAL WETLANDS
Alternative 1a. Turbidity plumes would be localized; if project-
Alternative 2a. Although depositional patterns would differ
There would be no increased potential for
related turbidity did enter any of the various lagoons, particulate
when compared to Alternative 1, no significant impacts are
change to lagoon sedimentation volumes or
concentrations would be low given the distance to the lagoon and
anticipated. The monitoring program in Section ES-5 would be
lagoon mouth closures above the current
rapid settling rate of the predominantly sandy material. Impacts
implemented to verify no significant impact or implement
patterns.
would not be significant. The proposed project may incrementally
corrective action, as necessary.
increase the volume of sedimentation over that which occurs
currently for several lagoons, but the lagoon monitoring program
Alternative 2b. Potential effects at individual lagoons would not
would be implemented as part of this project to verify no
be any greater under this construction variation. The monitoring
significant impacts or implement fair-share maintenance dredging
program in Section ES-5 would be implemented to verify no
or lagoon mouth opening. Therefore significant impacts would not
significant impact or implement corrective action, as necessary.
result (refer to Section ES-5).
Alternative 1b. Potential effects at individual lagoons would not be
any greater under this construction variation. The monitoring
program in Section ES-5 would be implemented to verify no
significant impact or implement corrective action, as necessary.
WATER RESOURCES
Alternative 1a. None of the fill material would exceed the criteria
Alternative 2a. Construction at several receiver sites would take
As no dredging or replenishment activities are
established in the California Ocean Plan for bacteria, dissolved
incrementally longer under this alternative than Alternative 1
proposed under this alternative. No change to
oxygen, contaminants and sulfides, nutrients or pH and there would
because they would receive more sand. Still, the impacts would
water quality would result.
be no impacts associated with placement of fill material at the
remain localized and training dikes would help reduce turbidity.
receiver sites. Due to the localized nature of turbidity plumes, and
No significant impacts to water quality would occur at any
the presence of training dikes, there would be no significant
receiver sites. Significant elevations in turbidity would not result
impacts to water quality at the receiver sites. No violation of the
in significant impacts to water quality at any of the borrow sites
California Ocean Plan objectives would occur from dredging any of
given the relative localized nature of the turbidity plumes, and
the borrow sites. Based on the relatively localized nature of the
rapid diluting capacity of the open ocean. Some monitoring
dredge turbidity plumes
would be required consistent with the RWQCB permit.
Page ES-22
Regional Beach Sand Project EIR/EA
99-69\SANDAG EIREA es.wpd 7/17/00
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