EVEREST June, 2013 - California Department of Boating and ...

Orange County Coastal Regional Sediment Management Plan
list of impaired water bodies after USEPA found unacceptable levels of polychlorinated
biphenyls (PCBs) and dieldrin. Since much of the shoaling identified in 2000 was located near
drainage outlets, there is concern that the sediment buildup might be so contaminated with toxic
metals, pesticides, and PCB’s that special dredging and other management measures may be
required for sediment disposal. It is unknown if or how much of the sediment proposed to be
dredged from Huntington Harbour can be placed on the beach or nearshore, so investigation
into this matter is recommended.
4.22 Update the Plan
The Plan should be a living document that would benefit from periodic updates to add or modify
data, information, understanding, and recommended activities. The Plan should be updated
using a collaborative approach between the various stakeholders and led by either the new JPA
(see Section 4.2) or Orange County and USACE. The update should include a review of the
coastal RSM strategies outlined in the current Plan, modifications to activities based on lessons
learned, and potential additional activities as appropriate. Much of the updated understanding
should come as direct results from the studies recommended within the Plan activities. As with
the current Plan, future modifications should be carried out in a transparent fashion with full
cooperation and inclusion of the stakeholders and the public in general.
4.23 Update Sediment Budget for Laguna Beach Littoral Cell
The most recent sediment budget for the Laguna Beach Littoral Cell was for a time period
ending in 1984 (USACE, 2002b). Given the large amount of development occurring in the area
in the last 28 years, it is expected that sediment yields and the sediment budget for this area
have changed significantly. This activity would be to update the sediment budget for the
Laguna Beach Littoral Cell to better represent current conditions.
4.24 Investigate Methods to Assess and Mitigate for Upstream Sand Mining
This activity would be to perform a study to identify methods to assess and mitigate for removal
of beach sand from upstream creeks, streams and river beds.
4.25 Study Large Grain Size Impacts at East Beach, Seal Beach
This activity would be to perform a study to determine if use of larger than native grain sizes for
beach nourishment has caused negative impacts to surfing or habitats at East Beach in Seal
Beach. The positive effects of using large grain sand in beach nourishments are understood to
increase beach width and increase sand retention, thus lowering maintenance costs, but
potential negative impacts are less understood.
Everest International Consultants, Inc. 4.16