Chapter 1: The Feasibility Study • Rancho Palos Verdes, California
Draft Feasibility Report
Chapter 1. The Feasibility Study
The Rancho Palos Verdes Feasibility Study was authorized by the Water Resources
Development Act of 1986 and the Water Resources Development Act of 1990.
WRDA 1986, Section 712 •
"The Secretary is authorized to study the feasibility of constructing shoreline erosion
mitigation measures along the Rancho Palos Verdes coastline and in the city of Rolling Hills,
California for the purpose of providing additional stabilization for the Portugese Bend landslide
area and adjacent landslide areas..."
WRDA 1990, Section 116c
•
ID The Secretary shall:
1. complete the study of the feasibility of constructing shoreline erosion mitigation
measures along the Rancho Palos Verdes coastline and in the city of Rolling Hills, California
authorized by Section 712 of the Water Resources Development Act of 1986 (100 Stat. 4160);
and
2. in connection with such study, investigate measures to conserve fish and wildlife(as
specified in section 704 of the Water Resources Development Act of 1986) including
measures to demonstrate the effectiveness of intertidal marine habitat."
Corps of Engineers Study Activity
A reconnaissance study was initiated in October 1988, and completed in 1990 with a
recommendation to proceed to a feasibility study based on a plan to help stabilize the
landslide. A decision by the Assistant Secretary of the Army stated in a letter dated 28 Oct
1991, that"Landslide stabilization is outside the purview of the Army Civil Works program".
The reconnaissance report was revised to reflect that decision, and no further study was
recommended at that time.
However, in the Energy and Water Development Appropriation Act of 1994, Congress
provided funds for the initiation of a feasibility study at Rancho Palos Verdes, California. An
• Initial Project Management Plan (IPMP), focusing on the project purpose of restoring marine
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habitat along the coast of Portuguese Bend and adjacent areas, was completed and
negotiated with the City of Rancho Palos Verdes and approved by the Office of the Chief of
Engineers. A Feasibility Cost Sharing Agreement was executed between the City of Rancho
Palos Verdes and the U.S. Army Corps of Engineers in December 1995, and the Feasibility
Study was initiated.
Study Purpose And Scope
The Rancho Palos Verdes Feasibility Study purpose was to determine the Federal
interest in the development and implementation of shoreline erosion mitigation and marine
habitat restoration measures to restore the environment in Portuguese Bend Cove and
adjacent areas.
This Feasibility Report includes an analysis of the magnitude of degradation of the
nearshore ecosystem along Portuguese Bend and adjacent upcoast and downcoast areas.
The report examines the likely cause of this degradation focusing on earlier studies that
indicate a primary cause being the relationship between the local landslide movement, erosion
of landslide bluff material, and sediment deposition and increased turbidity within the marine
environment. The report slide, and the seaward limits of the slide to determine design
considerations and constraints for restoration and erosion control measures. The Feasibility
Report does not address the stabilization of the landslide. Measures to control erosion of the
bluff, sediment deposition and turbidity as well as other measures considered viable to restore
the marine ecology are developed and evaluated in this report based on considering costs,
environmental outputs, potential adverse impacts, and other criteria to select a Recommended
Plan. The report presents the Federal and non-Federal requirements for implementation of a
plan selected for implementation based on Federal laws, policies, and guidelines.
The feasibility study and the formulation and evaluation of alternative plans was
conducted in accordance with the Economic and Environmental Principles and Guidelines for
Water and Related Land Resources Implementation Studies (P&G), Corps of Engineers
Engineer Regulation 1105-2-100, and other authorities that establish and define the goals and
requirements for water resources planning procedures and reports. The study and report also
complies with the National Environmental Policy Act of 1969, as amended, the California
Environmental Quality Act, and other Federal and State laws, policies and guidelines to
regulate and protect the Nation's environmental resources.
Study Participation And Coordination
The City of Rancho Palos Verdes was the Non-Federal sponsor of the Feasibility Study
which was conducted as a 50%-50% cost shared partnership between the City and the Corps
of Engineers. Rancho Palos Verdes representatives took an active role in the conduct of the
total study effort, which was conducted under a Feasibility Cost Sharing Agreement executed
in December 1995. The study included coordination with all appropriate Federal, State, County
and local agencies, groups, and interested individuals. These entities provided pertinent data
and professional insight into the perceived problems and needs of the Study Area. They also
provided data and analyses as input into the development, assessment and evaluation of the
alternative solutions and the selection of the Recommended Plan.Agencies included in the
coordination process include the following:
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• Federal Agencies
U.S. Environmental Protection Agency
U.S. Department of Interior, Fish and Wildlife Service
U.S. Department of Commerce, National Marine Fisheries Service
U.S. Department of Commerce, National Oceanic and Atmospheric Administration
State Agencies
California Coastal Commission
California Department of Fish and Game
California Department of Boating and Waterways
California Regional Water Quality Control Board
California State Office of Historic Preservation
California State Lands Commission
Local Agencies
City of Rancho Palos Verdes
City of Rolling Hills
Los Angeles County Department of Sanitation
South Coast Air Quality Management District
Prior Corps of Engineers Studies, Reports, and Existing Projects
IDThe only study and report previously completed by the Corps of Engineers in this area
was the Rancho Palos Verdes and Rolling Hills, California Reconnaissance Study to identify
shore protection measures that would provide additional landslide stabilization at the shoreline.
The final report was completed in May 1992. The report presents a preliminary evaluation of
the problems and needs related to landslide stability causing damage to development and
environmental degradation. It also presents a preliminary evaluation of a range of alternative
plans to control erosion of the landslide that might contribute to stabilization of the landslide
thereby reducing damage potential and restoring the environment. The report notes the
complexity of the landslide and that there is uncertainty on the effectiveness of landslide
measures.
There are no existing Corps of Engineers projects in the Study Area.
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