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Chapter 5: The Recommended Plan Rancho Palos Verdes,California Draft Feasibility Report Chapter 5. The Recommended Plan The Rancho Palos Verdes plan formulation process resulted in the selection of Alternative Plan 2 as the Recommended Plan. This plan will best contribute to the Study ecological restoration objectives by restoring the kelp forest along the Portuguese Bend Cove shoreline. The Plan is selected as the National Ecological Restoration (NER) Plan providing the most cost effective means of restoring substantial net average annual habitat units. From an adverse environmental impact analysis standpoint, the Recommended Plan is not expected to result in any significant adverse environmental impacts, although there will be loss of habitat area behind the dike structure, and the dike structure itself will create an aesthetic change to the open ocean view of Portuguese Bend Cove. Plan Description The Recommended Plan, illustrated in Figure 5-1, consists of constructing a containment dike at a depth of about-18 feet MLLW in Portuguese Bend Cove, about 400 feet offshore of the Portuguese Bend landslide bluff shoreline. The dike will tie into Inspiration Point on the westerly end, and on the easterly end the dike will tie in to a stable area between the landslide and drainage ditch. '• Plan Design The Recommended Plan was designed to retain landslide generated sediment. The Recommended Plan is an attached containment dike, which also functions as a breakwater. The structure will retain landslide sediment in two ways: First, the structure will reduce erosion of the landslide bluff toe by significantly decreasing transmitted wave heights; and second, the water region located between the structure and the landslide will act as a settling basin. Most of the sediment that is input from the landslide into this basin will settle on the bottom. Fine material that does remain suspended will have difficulty transmitting through the structure as its core will act as filter. With a core height of+6 ft MLLW, most of the suspended fines will be retained. It is expected that during extreme events, more of the fines will be transmitted through the structure, but this is not expected to be a significant impact to the environment, as turbidity levels are normally elevated during these events anyway. Structural Cross Section Design Figure 5-2 shows the Recommended Plan cross-section design. The design wave for determining section requirements and stone sizes was based on the depth limited wave at each section and a wave period of 17 seconds, considered representative of larger wave events at the site. Armor stone sizes for various depth regions are shown in Table 5-1.An armor stone crest width of three stones and an armor stone layer thickness of two stones was calculated as the stable design cross section. The under layer for the structure includes stone sizes of 1/10th the weight of the armor stone. 5-1 w ...... •• ig • •., i 1,.....„:%,.........i .,.. .....„ C 00011330'Wald!! .1 NA1.00001M SM. ....0.21.- CO we ..,...., 01,U via al 0S-C vili Av MO (1) ' O I 000.0.30 a Ally .al• Oi .9. S3ItivA C . ,04.1 AiviiiRaZi: ,owl , 2.0ASI%Oa ........„,------- • -A ._--.-----..,. O . .......„/„...........,----„,-- Aso0 1....V-i'l --",-„, --.....---..,„...,':1 -, ! - .„.,••• -'----- I .82 I, r -, -•••-......L./--••••'"- 1 ••••• 1.1...'...--„, .01 3,......„..... ..„,....- -.--- ••• ----...ii I---. ••••& .....„,••••• C? -„ #001516 AI, . XIII trr230 41114 •le,--- ---"..." 0 0 arrrarsr-ire-org C U-U.01 LUG 10 t vA I a; /CM .ri• OA .r•SaltslA O. • --,-.-.—. . ,.. . 1 _ - .---- "r _____...._ CNI V .1-.61-1 -,_ ---A--/ ..."..3....-->....- "-''.."" ,,, 1•' • in W ,. 13 2'......,' ...(1OIS12.111 ,•-',.20 3COS ov3:10 C I.."... • • Di "ALAI 11••• ......„..---..-- IS .111•SliVrA ' ---- E o o . ,o ovorvi-g-arbmr-ins pc•r 10/9 OA SO••vAS IL a.0'Amass lomo.41 v.t.N01/13$"W'Sarrl CNi AVON .S. 04. .S. IUINVA All! .01. 0! Ar.Salvv4L.1_•-------•-----.. ------ -- ...• . ...... ...=- S3OA 1/.0AS,9.0 4 .,'. ---..., •-, "-i-- - I01••• .ri•------ ••••••„, ....„,...' „..,..--" Avi06,0•SvIS OA ,C•2 vie vavA/1/1 .1.. I VAS ATVs .Ca• Di .51. MANS ---- 0) Alliu INI•S VII UI 11C.2 VII H24346 ir. kr] Table 5-1. Stone Sizes Recommended Plan Armor Under- Stone Layer Crest layer Layer Reach Weight Width Width Weight Width Type (Sta to Sta) (tons) (feet) (feet) (tons) (feet) Sec 0+00 to 2+30 1 4.5 7 n/a n/a A-A 2+30 to 5+30 6 8 13 0.6 4 B-B 5+30 to 22+70 9 10 14 1 5 C-C 22+70 to 25+20 6 8 13 0.6 4 D-D The crest elevation for each section was designed to minimize structure overtopping resulting in a maximum crest elevation of+21 feet MLLW. The core elevation of+ 6 feet MLLW and core thickness shown in Figure 5-2 are designed to minimize wave transmission through the permeable structure, resulting in an average transmission of less than one inch, with higher transmission heights occurring during extreme events. Breakwater Materials I# There are many quarries within a 120-mile radius of the project site which could furnish stone suitable for the recommended plan. Some of these quarries are located in Riverside, Corona, Colton, and Catalina Island. Breakwater Construction The Recommended Plan can be constructed using a land-based or combination land and water-based operation. A land-based operation would involve one or more truck mounted cranes, one or more loaders, dozers, excavators, and many rock trucks. The stone would be trucked to the site and stockpiled. It would be placed using a crane, excavator, dozer or loader. Interlocked placement will be required for the A-Stone. A crane or excavator will likely place the large stone. Smaller stone may be placed with a crane using a skip bucket or an orange peel. An excavator, dozer, or loader may also be used to place small stone. The contractor would likely build his way out on newly constructed structure, possibly from both ends. A water-based operation would involve placing stone using a crane mounted on a derrick barge. Large stone will be placed using rock tongs, while smaller stone will be placed using a skip bucket or orange peel. The rock barges will be moored alongside the derrick barge. Tug boats would be required to tow the rock barges and to position the derrick barge. A land-based operation is required to build the two land-oriented portions of the structure using the previously described land-based methods 5-3 OMRR&R Alba Armor stone maintenance of the structure because of storm impacts is expected to be minimal over the 50-year project life because the breakwater is designed for depth limited waves. The structure is designed based on information that indicates the foundation is stable 400 feet seaward of the landslide bluff toe. Based on this, no maintenance is expected due to deformation of the foundation. Because of the uncertainty on future landslide movement, it is assumed that there is some potential for the dike structure to be impacted continuous movement of the landslide in the future. The analysis of landslide impacts was based on the assumption that the entire landslide bluff would continue to move at an average rate of about seven feet per year. It is noted that recent monitoring by the City of Rancho Palos Verdes shows some sections of the bluff moving at slower rates or even stable. Further, additional actions by the City to stabilize the landslide movement may further reduce the average annual rate. There is also a potential that during times of high rainfall the landslide can move at a higher rate. Based on this average annual rate, the landslide toe is expected to reach the structure in about 57 years. The recommended plan includes the requirement for removal of material to avoid encroachment of the landslide within 50 feet of the dike structure. This will require removal of about 146,000 cubic yards a year after year 50, or a total of about 7 million cubic yards of material to extend the life of the project another 50 years. It is emphasized the quantity and frequency of removal is subject to the rate of landslide movement and how the material fills in 01 behind the dike. The average annual rate used provides a reasonable estimate at this time on removal requirements. The material that will be removed will consist of sand, silt, clay sized material plus any miscellaneous debris (tree stumps, vegetable matter, trash, etc) encountered. The debris will be separated and disposed of in a local landfill. The other material will be disposed of in the LA-2 Disposal Site, located eight nautical miles southeast of the project site. A portion of the material behind the dike will be submerged in the water behind the dike, while a portion will be dry adjacent to the landslide bluff. Two methods of maintenance are possible. One method (Option 1) is to remove the material and transport it via conveyor belt to barges moored just offshore of the dike. The barges would be towed to LA-2 with a tug boat and disposed. The second method (Option 2) is to remove the material and transport it via truck to barges berthed at Los Angeles or Long Beach Harbor. The barges would be towed to LA-2 with a tug boat and disposed. The major equipment required for Option 1 includes a conveyor belt, a truck mounted or crawler crane, one or more loaders, one ormore dozers, one or more tug boats, and a number of barges. The major equipment required for Option 2 includes one or more truck mounted or crawler cranes, one or more loaders, one or more dozers, one or more tug boats, a number of barges, and multiple trucks. 5-4 1VA Real Estate Structure Requirements The structure is primarily located in waters along the City of Rancho Palos Verdes. These waters are under the jurisdiction of the California State Lands Commission. Approval from the the State Lands Commission will be required for construction of the dike as well as areas behind the dike that will fill with landslide materials. At the westerly end of the dike tying into Inspiration Point, these properties are owned by the City of Rancho Palos Verdes, as well as the westerly tie-in between the landslide and a drainage ditch. Construction Easement A staging area of about four acres is expected to be needed for contractors trailer and landside equipment and parts as well as storage of materials. It is expected that these lands will be located on City Property adjacent to the landslide. In addition access from public roads to the construction site will be needed. It is likely, that a new access road will be constructed Palos Verdes Boulevard South to the construction site to allow for project construction as well as any future maintenance. It is expected the area adjacent to the landslide on City property will be used for access. Environmental Requirements and Commitments Environmental Impact Statement/Report The environmental impacts of the Recommended Plan are addressed in the Environmental Impact Statement/Environmental Impact Report that follows the Main Report in this Volume. Information in the EIS/EIR shows the compliance of the selected plan with environmental requirements designated by the Federal Government and State of California in response to guidelines for compliance-to-the National Environmental Policy Act and California Environmental Quality Act as well as other Federal and state laws and guidelines. A summary of the impacts associated with responses in compliance to these requirements is presented below. Environmental Impacts of Recommended Plan Marine Ecology Significant net beneficial impacts to the nearshore marine environment of Portuguese Bend and immediately downcoast are expected. The Recommended Plan is expected to result in the restoration of some 80 acres of hardrock reef that is currently covered with landslide- generated sediment. This area is expected to be restored as a robust healthy kelp forest habitat and ecosystem and associated marine plants and aquatic life. Also,the quality of some 400 acres of existing kelp bed would be improved to optimal conditions as the near-constant , nearshore turbidity plume is eliminated. An adverse impact is expected from the loss of about nine acres of existing, poor quality marine habitat that is currently impacted by sediment deposition and turbidity from the landslide which would be lost under and/or behind the dike. This impact is expected to be 1-410 5-5 more than offset by the large beneficial impact to marine biological community. Essential Fish Habitat The 1996 amendments to the Magnuson-Stevens Fishery Management and Conservation Act set forth a number of new mandates for the National Marine Fisheries Service (NMFS), regional fishery management councils, and other federal agencies to identify and protect important marine and anadromous fish habitat. The Councils, with assistance from NMFS, are required to delineate "essential fish habitat" (EFH)for all managed species. The Act defines EFH as " . . . those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity." Federal action agencies which fund, permit, or carry out activities that may adversely impact EFH are required to consult with NMFS regarding the potential effects of their actions on EFH, and respond in writing to the fishery service's recommendations. For the Pacific Region, EFH has been identified for a total of 89 species covered by three Fishery Management Plans (FMPs) under the auspices of the Pacific Fishery Management Council (see NMFS 1998:Table 1). Several of these "managed"species are known to occur in the study area (e.g., Northern anchovy, leopard shark, big skate, Dover sole, rockfish, and others indicated in the EIS). Also many other native marine fish in the study area undoubtedly serve as prey for many of"managed"species. Also, the Rancho Palos Verdes study area is located within an area designated as EFH for the Coastal Pelagics and Pacific Groundfish Management Plans. Many native marine fish are expected to benefit from eliminating the negative impacts that the landslide-generated sediment has had on covering hard rock reef and the negative impacts that the near-constant turbidity plume has on existing kelp beds downcoast. Several "managed species" (i.e., species covered by the three fishery management plans (FMPs) under the auspices of the Pacific Fishery Management Council occur in the project area. Also, many other native marine fish in the study area undoubtedly serve as prey for many of the managed species. Eliminating the negative impacts of the landslide-generated sediment and turbidity from the nearshore marine environment is expected, therefore, to improve the habitat quality of"managed"fish species and fish that may serve as prey for managed species. As such, the Corps has determined that the proposed restoration plan is expected to have a significant net beneficial impact on Essential Fish Habitat. Further information on the ecological restoration benefits and costs is presented later in this Chapter under Plan Benefits. Coastal Zone Biology Temporary disturbance due to construction activities is expected to occur for a one to two year period to coastal zone or terrestrial vegetation or wildlife from implementation of the Recommended Plan. This includes primarily the area for haul roads and construction related vehicles. The haul road is expected to be located on areas presently disturbed and degraded due to the landslide and stabilization efforts. These areas will be completely restored after construction. The dike's attachment to the shoreline involves only about one-half acre of 5-6 nearshore area adjacent to the landslide and a drainage ditch by the Portuguese Bend Club. IMF This area of the shoreline is highly disturbed by landslide movement and at best has only rederal vegetation. The proposed offshore dike and landslide sediment buildup behind the dike are not expected to contribute to stabilization of the landslide nor its current rate of movement. The restoration of kelp forest and reduction in turbidity in the area could have some benefits to foraging birds such as spotted sandpiper, wandering tattler, whimbrel and the black and ruddy tumstones. Endangered and Threatened Species No adverse impacts are expected to be caused to any Federal or State listed threatened or endangered species. There may be some benefit to brown pelicans who could use the dike structure as a day roost. Since the dike is attached to the shoreline, it probably will not be used as a night roost. Recreation The reduction in turbidity and restoration and improvement of kelp forest could have beneficial impacts to recreational fishing, lobstering, and scuba diving activities from the Portuguese Bend area to Whites Point. No adverse impacts are expected as a result of the project, except for the possibility of some minor noise and traffic impacts during construction to members visiting the Portuguese Bend Club. Water Quality 1/0 The quality of water behind the dike is of some concern. It is estimated that 27% of the water volume would be exchanged during each tidal cycle and, therefore, should not create any significant deterioration of the water quality. A more quantitative evaluation of the movement and exchange of water behind the dike is proposed during Pre-construction Engineering and Design phase using three dimensional numerical hydrodynamic and water quality models at the U.S. Army Corps of Engineers Waterways Experiment Station to verify this assessment. If necessary, some design modifications can be made to the plan to allow increases in wave and tidal transmission through the structure, while minimizing increases in turbidity. Cultural and Historic Resources Information available indicates no evidence of cultural or historic resources in the area that would be adversely impacted by the Recommended Plan. Further field analysis will be performed as needed during Pre-construction Engineering and Design based on final dike alignments. Air Quality An analysis of air quality impacts associated with the Recommended Plan indicates'. some potential for short term adverse impacts during construction, particularly with the exceedence of NOX standards. This is dependent on the type and condition of the contractors • 5-7 equipment. The contractors will be required to obtain necessary permits from the Air Quality Control Board for operation of the equipment, which should resolve the potential impact. Of some concern is the impact of hauling stone using a land-side operation, which may exceed allowable Nox levels above allowable daily standards. This could be mitigated by limiting the number of truck trips per day, which could extend the construction period three months. Hazardous and Toxic Wastes There is no evidence of hazardous or toxic wastes present in the immediate project area, except as related to contaminated sediments which are discussed below. Aesthetics The proposed dikes would be a significant, hard structure constructed along the coast. The dike would be about+21 feet above Mean Low Low Water and about 14 feet across its widest section. Despite its size, from land the dike should only be visible to residents of Portuguese Bend, and those high areas on the Palos Verdes Peninsula that can view Portuguese Bend Cove. The structure would also be visible from Inspiration Point, but there is no public access to Inspiration Point. Significant benefits to the aesthetic quality of the ocean view could be realized if the structure eliminates the large turbidity plume that is visible from several shoreline locations. Although the impact on aesthetics can be considered adverse, it is not considered significant. Sediment Chemical Contamination The major area of concerns on sediment contamination are related to the uncovering of •' buried contamination of sediment that could impact on their bio-availability to marine plants or animals, and the impact of reducing amount of clean sediments from the littoral environment that could be reaching and providing a significant cover to areas of contamination in Santa Monica Bay. As mentioned in Chapter 2, cadmium, nickel and DDE (a derivative of DDT)were detected in nearshore sediment. The most likely source of this contamination is the past discharges of contaminants from Whites Point and the resulting contaminated mound further offshore the Palos Verdes Peninsula. The contamination levels found in the nearshore cores taken in Portuguese Bend are similar to the "background" contaminated sediment levels in Santa Monica Bay and several times less than the levels found in and near the effluent- affected contaminated mound offshore the Peninsula. Accordingly, it is not expected that the scouring and uncovering of sediments at Portuguese Bend will cause any significant impact to surrounding environment. The sediment budget developed for the Feasibility Study and described in Chapter 2 indicates an average of about 79,000 cubic yards a year is transported out of the control volume (Portuguese Bend Cove and immediate downcoast area). It is possible that some of this sediment makes its way offshore beyond the-100 foot MLLW contour. It is subject to the predominant northwesterly mid and bottom current. However, based on discussions with EPA representatives and in view of the relative minor volume of material from Portuguese Bend that 1 5-8 is dispersed through the large Santa Monica Bay area including the contaminated mound, the effects of reducing the average annual volume of sediment that goes offshore is not considered significant. It is also noted that the Recommended Plan calls for removal of material behind the dike about every twenty years. At this time, LA-2 is identified as the disposal site for this material. However, if desired, arrangements can be made to dispose of this material to cap contaminated material sites identified by EPA. In this regard, the volume of material directly used to cover contaminated sites can be used to create a greater effect of capping. This will be discussed with EPA and other interests at the time sediment removal from behind the dike is required. Downcoast Shore Impacts In general the material from the landslide is not beach compatible and is not a source of material for any of the small pocket-type beaches along the downcoast areas. The design of the dike structure includes toe protection to prevent bottom scouring from currents along the structure. Immediately downcoast of the structure some scouring could occur which could have some minor impacts of the primarily cobble beach. Other Impacts Other impacts of concern are related to construction activities and include noise and traffic impacts. These impacts will be minimized through coordination with the City of Rancho �• Palos Verdes to meet established noise ordinances and to minimize impacts by using major truck routes and avoiding peak traffic periods as necessary. Summary of Environmental Commitments Table 5-2 is a summary listing of the environmental commitments that are incorporated into the Recommended Plan. Descriptions of the plan's impacts on significant environmental resources of principal national concern are described in the table. 5-9 Table 5-2. Environmental Commitments Oil Resource Commitment Air Quality Compliance with Federal, California and SCAQMD regulations. If necessary, set limits on daily truck trips Noise Compliance with City of Rancho Palos Verdes Noise Ordinance Cultural Compliance with Section 106 of the NHPA (36CFR800) prior to awarding construction contract Water Further analysis during final design to confirm no significant water quality impacts Sediment Contaminates Consider disposal of maintenance dredging to cap contaminated benthic areas in Santa Monica Bay. Compliance with Federal Laws and Policies The following information summarizes the study compliance with Federal laws and policies as related to protecting the nation's environmental and related resources. Further information is presented in the EIS/EIR. Fish &Wildlife Coordination Act 04 This statue requires Federal agencies to coordinate with the U.S. Fish &Wildlife Service (USFWS), applicable state agencies, and the National Marine Fisheries Service (NMFS), as appropriate, when a stream or body of water is proposed to be modified. The intent is to give fish and wildlife conservation equal consideration with other purposes of water resources development projects. Coordination with the USFWS, the NMFS, and the California Department of Fish and Game has been ongoing throughout the planning process. Numerous coordination meetings have been held with these resource agencies throughout the planning process. These agencies participated in the planning decisions that included the scope of marine biological surveys performed, the scope of the nearshore sediment surveys conducted, the scope and location of nearshore contaminate sediment surveys, and all aspects of the habitat valuation performed for this project. USFWS prepared a Planning Aid Report in December 1996 and a Draft Coordination Act Report(CAR) in April 1999. The Draft CAR appears as Appendix D of the EIR/EIS. The Corps' comments on the Draft CAR and the recommendations in the Draft CAR appear in Appendix of the EIS/EIR and discussed further in Public Coordination Chapter of this report.. Magnuson-Stevens Fishery Management and Conservation Act This Draft EIS/EIR includes an Essential Fish Habitat(EFH) Assessment as required by the Magnuson-Stevens Act, as amended. Although construction will occur within Essential Fish Habitat, the Corps has determined that this project would result in a significant net increase in 5-10 1111 beneficial impacts. In compliance with the coordination and consultation requirements of the Magnuson Stevens Act, the Draft EIS/EIR has been sent to NMFS for their review. Endangered Species Act The District received a list of threatened and endangered species that potentially could occur in the study area on 19 June 1998 (see Appendix J of the EIS/EIR). Section 7 (c) of the Endangered Species Act requires consultation with the U.S. Fish and Wildlife Service (USFWS)to determine if a Federal action may affect threatened or endangered species, and to ensure that any action does not jeopardize the continued existence or result in the destruction or adverse modification of designated critical habitat of any threatened or endangered species. A Biological Assessment was prepared to comply with the regulations on interagency cooperation regarding compliance with the Endangered Species Act(as per 50 CFR 402) (see Appendix J of the EIS/EIR.) These regulations require that a Biological Assessment be prepared to assess the potential impacts of Federal projects which are"major construction activities" on listed or proposed threatened and endangered species (50 CFR 402.12). The Biological Assessment concludes that the proposed project may have a beneficial affect on the California brown pelican and the California least tern. No effects are expected to any other threatened or endangered species known or expected to occur in the project area. The Corps is pursuing written concurrence of the USFWS of the assessment as provided '• under informal consultation (50 CFR 402.13). Clean Air Act The potential air quality impacts of the proposed project have beenexamined and have been compared to the significant levels identified by the South Coast Air Quality Management District(SCAQMD), which is the agency with jurisdiction to enforce the Clean Air Act regulations and other relevant local air quality regulations (see Appendix G). The SCAQMD sets the threshold limits which, if exceeded, trigger New Source Review Rules, as defined by the Clean Air Act. The air quality analysis in Appendix G demonstrates that the activities associated with this project are below de minimis levels prescribed in 40 CFR 93.153(b), and is, therefore, exempt from demonstrating conformity to State or Federal Implementation Plans. The project, as proposed, will not exceed the threshold limits, and is in compliance with the Clean Air Act, as amended. Clean Water Act Compliance with the guidelines in 40 CFR 230.10(c) (promulgated by EPA under Section 404(b) of the Clean Water Act), no discharge of dredged or fill material due to this project will be permitted which will cause or contribute to significant degradation of the waters of the U.S. The Corps will coordinate this project with the Los Angeles Regional Water Quality 5-11 Control Board. A Section 404(b)(1) evaluation was prepared for this project and is presented in the Appendices of the EIS/EIR. The evaluation determines that this project will not adversely impact water quality. National Historic Preservation Act of 1966 Coordination with the California State Historic Preservation Officer(SHPO)will occur in accordance with 36 CFR 800.4 once the required archeological identification studies are completed. Identification studies in the form of archival research, and if necessary, underwater archeological surveys may be required. Any necessary marine archeological surveys will be conducted during the PED phase to ensure compliance with the Act. National Register of Historic Places (NRHP) evaluations will need to be conducted for any sites that will be impacted as a result of the project. This may require subsurface test excavations. The results of these studies will need to be coordinated with the California State Historic Preservation Officer(SHPO) in accordance with Section 106 of the Act. If any archeological or historic sites are determined to be eligible for the NRHP, mitigation measures will be developed and agreed to in a Memorandum of Agreement(MOA). The signatories to the MOA will be the Corps, SHPO, and the Advisory Council on Historic Preservation. Execution of the MOA is required prior to the obligation of project funds and the awarding of construction.Any mitigation that is required will be completed prior to construction. Coastal Zone Management Act Section 307c(1) and (2) of the Coastal Zone Management Act require that federal agencies conducting, supporting, or undertaking development activities that are in, or directly affect the coastal zone of a state will insure that the project is, to the maximum extent practicable, consistent with approved state coastal management plans. The California Coastal Act is the state of California's approved coastal management program applicable to the proposed project. To document the degree of consistency with the. state's program, the Act and Federal Regulations (15 CFR 930.37) require the preparation of a Consistency Determination whenever a project could directly affect the coastal zone. A Consistency Determination (CD)was prepared and appears in Appendix Hof the EIS/EIR. The CD provides a description of the Proposed Action, identifies each relevant policy of the California Coastal Act, discusses the proposed action's consistency with each of the policies, and where applicable, describes measures, which when implemented, will result in project consistency with state policies to the maximum extent practicable. The proposed project activities have been determined to be consistent with the California Coastal Act to the maximum extent practicable, as required by the Coastal Zone Management Act of 1972. The California Coastal Commission (CCC) has been asked to concur with this determination. 5-12 � ' Executive Order 12898 Executive Order(EO) 12898, Environmental Justice in Minority and Low-Income Populations, directs federal agencies to assess the effects of their actions on minority and low- income populations within their region of influence. Agencies are encouraged to include demographic information related to race and income in their analysis of environmental and economic effects associated with their actions. The proposed action has no adverse affects on human or socioeconomic resources, and does not affect any minority or low-income populations. No disproportionately high or adverse human adverse human health or environmental effects would be born by minority or low-income populations through either a direct result of the proposed action or cumulative and/or indirect affects. The proposed action is, therefore, consistent with EO 12898 on Environmental Justice. Recommended Plan Costs This Section summarizes Recommended Plan costs. Details on construction methods and cost estimates are presented in the Coastal Engineering, Cost Estimates and Real Estate Appendices. First Cost '• This section presents the estimated first cost of implementing the Recommended Plan. Cost Estimate Method Construction-costs_.for the selected plan have been developed using the Corps of. Engineer's Micro-Computer Aided Cost Estimating System (M-CACES). Details of the construction cost estimate are included in the Cost Estimating Appendix. The cost estimate also includes costs for Planning Engineering and Design (PED) and Construction Management. Cost Estimate Table 5-3 presents the cost estimate for the Recommended Plan at October 2000 price levels. The total cost of the Recommended Plan is estimated at$27,440,000 for the dike structure. 5-13 • Table 5-3. Recommended Plan Cost Estimate and Environmental Benefits (Oct 2000 Price Levels) First Cost Construction Costs $23,537,000 Real Estate $35,000 Monitor and Adaptation Plan $460,000 Planning, Engineering, and Design $1,883,000 Supervision and Administration $1,525,000 Total First Cost $27,440,000 Average Annual Costs Interest and Amortization (6-5/8% interest rate/50 year economic life) $2,020,100 Operation, Maintenance, Major Replacements, Repairs (OMMRR) $117,700 Total Average Annual Cost $2,137,800 LERRD The cost or value of Lands, Easements, Rights-of-way, Relocations, and Disposal or borrow areas (LERRD) are estimated at$35,000, including a 0.9 acre permanent easement for anchor areas and 3.4 acres for a temporary construction easement on City-owned property. The costs include$4,000 in Federal costs for obtaining necessary easements and rights of entry and other administrative costs, and$5,000 in Non-Federal costs for providing necessary easements and rights of entry. Costs are included for acquisition of approvals to construct on ocean bottom project lands from California State Lands Commission. A credit of$31,000 will be provided to the City of Rancho Palos Verdes for the acquisition value of the temporary and dike tie-in land properties, which are owned by the City of Rancho Palos Verdes. Details of the estimated LERRD costs are presented in the Real Estate Appendix. Contingencies The cost estimate includes contingencies of 15%, (25% for Real Estate), based on considering the level of design presently available, potential changes in baseline conditions at the time of construction, and other uncertainties that may impact the project cost. Fully Funded Project Cost Estimate The estimated project cost, October 2000 price levels with inflation to the mid-point of construction or"fully funded estimate" is$ . The total inflation factor is 5-14 NIAverage Annual Cost Average annual costs estimated at$2,020,100 include interest and amortization of the financial cost of implementing the Recommended Plan, including first cost and interest during construction at an interest rate of 6-5/8% over a 50-year economic life. It also includes estimated average annual cost for Operation, Maintenance, Replacement, Repair, and Rehabilitation (OMRR&R) of the Recommended Plan over its 50-year economic life. OMRR&R Costs Maintenance of Dike Maintenance costs for the dike are expected to be minor, if any, since the design of the breakwater is based on the depth limited wave. Costs are estimated to be 0.5 percent of construction cost or$117,100. Maintenance Removal of Material Behind the Dike Maintenance to remove material from behind the dike is based on historical average annual rate of landslide movement of about seven feet per year which results in the potential for the annual movement of 146,000 cubic yards of landslide material sediment deposition behind the dike. The recommended plan would not require removal of material until after year 50 based on the average annual movement. At that time, removal of material would be required to avoid encroachment on the dike structure. The least costly method would be by conveyor and barge, the details of which are included in the Cost Estimates Appendix The '• cost of material removal based on October 2000 price levels is estimated to be about$8 million for removal of 700,000 cubic yards, every five years. Recommended Plan Benefits The Recommended Plan is designed to contain sedimentation and eliminate turbidity from entering the marine environment beyond the containment dike. The benefits of the Recommended Plan are restoration of the kelp forest ecology within Portuguese Bend Cove by the uncovering of rocky substrate out to a depth of-30 feet MLLW and reduction of turbidity within Portuguese Bend Cove. Ecosystem benefits are also expected out to-60 feet depths from the reduction of turbidity in the areas immediately adjacent to and downcoast of Portuguese Bend Cove to the Bunkers Point and Whites Point areas. These areas are shown in Figure 5-3. It is noted that there is potential for additional benefits to occur in the Abalone Cove area and as far downcoast as Point Fermin due to reduction of sediments from the landslide moving upcoast and reduction of turbidity. However, the timing and extent of the benefits in these areas may be impacted by other factors such as residual sediment from past slide activity at Abalone Cove and therefore are not included in the analysis. Details of the estimated ecological restoration benefits are presented in Appendix C to the Environmental Impact Statement/Report. 5-15 I i er /WS=IPS lig- MO AREA 1 !"� ��^��; AREA 2 « i lana, "• J\. TI `'`f �,• , ..... MAJOR CONTOURS AT 10 FOOT INTERVALS a :1 t1D —.r..—•—..... ::::H:::TS;:::: H::: (DILL AREA 4 W 11 POTENTIAL HARD BOTTOM RECOVERY AREA m o o 1to AREA 3 t! 1/414:11 . 0 AREA 5 3 tri al r 1 -, ••• Fig.5.1 Sediment thickness V) '4..•........ over bedrock `.0 and areas of N 0 potenWl restoration. 3 � ' 03m la 0 le°l.a4 a tell ONE \ 97 r. ''''''N':'').): ) NOTES. - to 111 1. HOLOCENE SEDIMENT THICKNESS OVER BEDROCK e` ._a�� ...1 ..:.=....... (CONTOURINTERVAL 5 FT/ . SOURCE. R.F. DILL ET AL, 1915 own 2. CORPS' 07-95 HYORO SURVEY CONTOURS AT 10 FT INTERVALS. Area 1-Area behind dike '�'.-:nl.i 3. LAND CONTOURS FROM 08.95 AERIAL SURVEY AT 10 FT INTERVALS. Ares 2-Nearshore area between-10 and-30 MLLW ®�ae ee a s n 1- ..wreiiiiawIo SUPPLIED BY THE CITY OF RPV. Area 3-Nurihore eru between-20 and-30 MLLW 11111SEDIMENT THICKNESS Area 4-Bunker Point Reef-existing kelp bed Area S-Bunker Pt.to Whites Pt Area-milling lial ® ... kelp bed with sediment covering 111Mel Y. of the area ""'� ,.. • 1111 Marine Biological Benefits Within the diked area, marine vegetation (consisting primarily of green algal mats) and benthic life associated with the soft bottom habitat(such as sea pens, sand stars, brittle stars and tube worms) are expected to be smothered by landslide sediment. The Recommended Plan effects of containing sediment and allowing the uncovering of rocky substrate out to-30 feet MLLW and reduced turbidity outside the dike is expected to allow for the restoration of about 50 acres of kelp forests that once existed in the Portuguese Bend Cove area, and improve existing 163 acres of kelp forests at Bunker Point and 230 nearshore acres of existing kelp forests from Bunker Point to Whites Point. This restoration is expected to create ecological conditions similar to that existing in Palos Verdes Point area: In addition, the oceanside of the dike itself will create intertidal and subtidal hard rock habitat. Intertidal and subtidal invertebrate animals are expected to colonize the structure immediately after its construction. The restoration of the kelp forests is expected to have significant beneficial effects to marine invertebrate and fisheries. The estimated value of the habitat restoration benefits are presented in following paragraphs. A new slide in the study area (about one mile downcoast of Portuguese Bend in the vicinity of Bunker Point) ruptured in June 1999 at the Ocean Trails Golf Club on the 18th fairway of a not-yet-completed golf course. The triangular land mass had surface dimensions of about 25 acres. The head of the slide ruptured about 600 feet inland, causing portions of the 150 foot high shoreline bluff to cascade down slope to the Pacific shoreline. The slide impacted about 2000 feet of shoreline and extended to about 200 feet in the nearshore area ,• in depths of-10 ft. to-15 ft. MLLW. The developer of the Ocean Trails Golf Course has plans to stabilize this slide and prevent bluff erosion and associated turbidity. This area of about 10 acres has not been deleted from the potential benefits from the recommended plan. Rate of Uncovering Rocky Habitat Existing sediment deposits on reef habitat in the nearshore zone, shown in Figure 5-3, are expected to be removed by natural processes including local seas and swell wave conditions, and longshore currents explained in Chapter 4 and detailed in the Coastal Engineering Appendix. For the Recommended Plan, the estimated uncovering rates and time required to expose rocky bottom for each deposition area are also shown in Table 5-4. 5-17 Table 5-4. Estimated Time Required to Expose Rocky Habitat Depth Surface Avg Sed Scour Years to Range Area Thick Volume Rate Uncover Area (ft to ft) (acres) (ft.) (cy) (cy/yr) (yrs) 2 -10 to-20 23 2.5 93,318 6,514 14 5 -10 to-20 18 2.5 70,686 6,514 11 2 -20 to -30 28 7.5 334,626 3,832 87 3 -20 to-30 11 2.0 33,991 3,832 9 5 -20 to-30 17 7.2 201,398 3,832 53 Improved Ecological System Those areas located within the containment dike are expected to be buried as landslide sediment moves into the basin area. Consequently, this area of about 17 acres although already of low quality because of landslide disturbance and high turbidity will experience further degradation due to the Recommended Plan. The natural scouring of sediment deposits seaward and downcoast of the containment dike are expected to uncover buried rocky habitat areas in the nearshore areas within the-30 feet isobath over time indicated habitat, which is impacted by frequent deposition of eroded sediment, would be restored to high quality hard bottom habitat with reduced turbidity resulting in a restored ecosystem of marine plants (especially giant kelp) and associated marine life. The reestablished kelp forest is expected to support a full complement of marine animals common to a kelp forest similar to the Palos Verdes Point Area. For the Recommended Plan, as shown on Figure 5-4, the rocky habitat areas expected to be uncovered and be restored include about 13 acres located between-10 feet and-20 feet in Area 2, 11 acres in Area 3, and 18 acres between-10 and -20 feet MLLW in Area 5. About 28 acres located between-20 and -30 feet, MLLW may not uncover sufficiently during the 50 year economic life, and accordingly no restoration benefit is being claimed for this area. In addition, no benefits were claimed for about 17 acres between -20 and-30 feet MLLW by in Area 5 since surveys of this area indicated low presence of kelp and presence of an urchin barren community. The turbidity plume and its associated water column impacts are reported to extend at least to the 30-foot isobath from Portuguese Bend to Whites Point. This area of impact includes the existing reef area at Bunker Point which is largely exposed and sediment free; and the nearshore area from Bunker Point to Whites Point. 1 • 5-18 • • • T ' 0. ul PROJECT cz N N o LIMITS AREA 1 i z ,` LEGEND. •REA 2 MAJOR CONTOURS AT 10 FOOT INTERVALS r ��__ ,:z:; HOLECENCE SEDIMENT THICKNESS CONTOUR (DILL) iiiitk.4410. �' ASSUMED HOLOCENE SEDIMENT THICKNESS 1) HABITAT RECOVERY/IMPACT AREAS C ���� 110 FT CONTOUR DEPTH IN FEET MLL11 0) 0� ': 5' SEDI*)T THICKNESS IN FEET cri1 i / ,::::\:::„.,.....„... ..:,.4 P iiihir m a1 AREA 3 UI °I t° 5'tx I ► ` , ; ` AREA 5 0 Fa / 0 VI ON OS LSO W Of s'''''N's-...- *....... .-s'-'\'‘'.:-N.' NOTES' NNISIMMINEININIIIIIIIIMIMIMMia=MI 1. HOLOCENE SEDIMENT THICKNESS OVER BEDROCK UM IIMINNIMINIIII1111111111111111 liMil la1111MA (CONTOUR INTERVAL 5 FT) . SOURCE. R.F. DILL ET AL. 1945 en Ills IBUI� .4111TLIR ST Of 2. USAGE JULY 1995 HYDRO SURVEY CONTOURS AT 10 FT INTERVALS. a mur�,a�aeolnr 3. LAND CONTOURS FROM 08-95 AERIAL SURVEY AT 10 FT INTERVALS. i PLATE SEDIMENT THICKNESS RECOVERY/IMPACT AREAS SUPPLIED BY THE CITY OF RPV, w.sw a The impacts of turbidity (i.e., decreased light penetration) on marine plants, especially giant kelp, is considered to be the primary factor that is degrading the quality of the ecology downstream of Portuguese Bend. Because marine plants depend on light for photosynthesis, turbid waters inhibits plant growth which in turn limits the marine animals that feed on the plants. The marine biological community, therefore, is expected to benefit from improved water clarity as turbidity is reduced which should occur immediately after construction of the containment dike is completed. In addition to the areas indicated above that would uncover rocky habitat, the areas that are expected to benefit from the reduced turbidity include 17 acres between-20 and -30 feet, MLLW in Portuguese Bend Cove (Area 2), 163 acres in the Bunker Point area(Area 4), and about 195 acres in the existing kelp bed area located between Bunker Point to Whites Point Area (Area 5). With-Project Habitat Values Tables 5-5 to 5-12 show the estimated habitat values for the Recommended Plan at locations shown on Figure 5-3 and described above. The Average Annual Habitat Units were derived considering the number of years it would take to uncover sediment covered rocky substrate and with the expectation that full recover would occur to an ecology similar to Palos Verdes Point. It was assumed that by the time the area was completely uncovered naturally, the habitat value might ve at an intermediate level of 0.5. the following year the habitat value is estimated to reach an optimal level of 1.0. used in the Tables. Table 5-5. Average Annual Habitat Areas With the Recommended Plan Area 1 —Portuguese Bend Area Behind the Dike111, Habitat Units/ Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .15 17 2.55 — 1 0.0 17 0 1.28 5 0 17 0 0 50 0 17 0 0 Sum of Habitat Units between Target Years 1.28 Average Annual Habitat Units—over 50 years .03 5-20 41), • Table 5-6. Average Annual Habitat Areas With the Recommended Plan Area 2 —Portuguese Bend Area from -10 Feet MLLW to -20 feet MLLW Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .15 13 1.95 — 1 .15 13 1.95 1.95 14 .5 13 6.5 54.93 15 1 13 13 9.75 17 1 13 13 26.0 50 1 13 13 429.00 Sum of Habitat Units between Target Years 521.63 Average Annual Habitat Units—over 50 years 10.43 • Table 5-7. Average Annual Habitat Areas With the Recommended Plan Ares 2-=Portuguese Bend_Area from-20 Feet MLLW to-30 feet MLLW Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .15 28 4.2 — 1 .15 28 4.2 4.2 15 .15 28 4.2 58.8 50 .15 28 4.2 147.0 Sum of Habitat Units between Target Years 210.0 Average Annual Habitat Units—over 50 years 4.2 111 5-21 Iii: Table 5-8. Average Annual Habitat Areas With the Recommended Plan-Area 3 Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .15 11 1.65 — 1 .15 11 1.65 1.65 9 .5 11 5.50 28.60 10 1 11 11.00 8.25 20 1 11 11.00 110.00 50 1 11 11.00 330.00 Sum of Habitat Units between Target Years 478.50 Average Annual Habitat Units—over 50 years 9.57 • Table 5-9. Average Annual Habitat Areas With the Recommended Plan Area 4—Bunker Point Area Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .39 163 57.05 — 1 1 163 163 110.03 15 1 163 163 2282 50 1 163 163 5705 Sum of Habitat Units between Target Years 8,097.03 Average Annual Habitat Units—over 50 years 161.94 ID 5-22 • • Table 5-10. Average Annual Habitat Areas with the Recommended Plan Area 2—Bunker Point-Whites Point from -10 feet MLLW to-20 feet MLLW Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .39 18 7.02 — 1 .39 18 7.02 7.02 9 .5 18 9 80.1 10 1 18 18 13.5 20 1 18 18 144 50 1 18 18 540 Sum of Habitat Units between Target Years 784.62 Average Annual Habitat Units—over 50 years 15.69 • Table 5-11. Average Annual Habitat Areas with the Recommended Plan Area 2—Bunker Point-Whites Point from -20 feet MLLW to 40 feet MLLW Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .39 17 6.63 — 1 .39 17 6.63 6.63 30 .39 17 6.63 192.27 50 .39 17 6.63 132.6 Sum of Habitat Units between Target Years 331.5 Average Annual Habitat Units—over 50 years 6.63 • 5-23 • Table 5-12. Average Annual Habitat Areas With the Recommended Plan Area 5—Existing Kelp Bed in the Bunker Point-Whites Point Area Habitat Units Target Year Habitat Value Area in Acres Habitat Units Target Years 0 .39 195 76.05 — 1 1 195 195 135.53 15 1 195 195 2,730 50 1 195 195 6,825 Sum of Habitat Units between Target Years 9,690.53 Average Annual Habitat Units—over 50 years 193.81 Table 5-13 summarizes the Average Annual Habitat Units expected to be generated as a result of the implementation of the Recommended Plan over the 50-year economic life of the project. Table 5-13. Habitat Values in the Study Area • Expected to Be Achieved Under Recommended Plan (in AAHUs) Location AAUUs. Portuguese Bend- behind the dike +0.03 Portuguese Bend (-10 to-20') +18.5 Portuguese Bend (-20 to-30') +4.2 Portuguese Bend-Area 3 +9.6 Bunker Point(Area 4) +161.9 Bunker Pt-Whites Pt. (-10 to-20') +15.7 Bunker Pt-Whites Pt. (-20 to-30') +6.6 Bunker Pt-Whites Pt.- kelp bed +193.8 Total +410.3 5-24 The net gain in habitat units from the nearshore and offshore dikes are summarized in Table 5-14. The loss of habitat behind either dike is expected to be offset by the restored habitat value of the immediate Portuguese Bend area alone. When added to the additional benefits expected from: 1) eliminating turbidity impacts at Bunker Point and the Bunker Point to Whites Point area, and 2) re-exposing hard rock reef at Portuguese Bend and nearshore areas downcoast of Bunker Point, the beneficial impact(i.e., positive gain in habitat units) is expected to be significant. Table 5-14. Net Gain in Habitat Units With-Project Versus Without-Project (In AAHUs) Future Future w/o Change Location w/Project Project in HUs' Portuguese Bend 32.4 10.7 +21.7 Bunker Point 161.9 60.6 +101.3 111, Bunker Pt to Whites Pt 216.1 89.7 +126.4 Total 410.4 161 241.3 Economic/Environmental Analysis The analysis of the costs and benefits of the Recommended Plan, shown in Table 5- 15, indicates an average annual cost of$5,600 per average annual habitat unit. .• 5-25 Table 5-15. Recommended Plan Cost Estimate 110 and Environmental Benefits (October 2000 Price Levels) First Cost Construction Costs $23,537,000 Real Estate $35,000 Monitor and Adaptation Plan $460,000 Planning, Engineering, and Design $1,883,000 Supervision and Administration $1,525,000 Total First Cost $27,440,000 Average Annual Costs Interest and Amortization (6-5/8% interest rate/50 year economic life) $2,020,100 Operation, Maintenance, Major Replacements, Repairs (OMMRR) $117,700 Total Average Annual Cost $2,137,800 Environmental Restoration Benefits Average annual habitat units (AAHU) increase 241.3 Incremental Cost Analysis $8,900/AAHU Comparison with Artificial Reef Estimated Cost In 1996 the California Department of Fish and Game (CDF&G) provided the California Coastal Commission (CCC) a cost estimate of building a low profile artificial reef. The request was made by the CCC in an attempt to get a "handle" on what the cost to an applicant might be should the CCC require an applicant to construct a low profile artificial reef as mitigation for impacts to existing natural rocky reef. Information provided by the Coordinator of CDF&G's Artificial Reef Program provided an estimate of$18,847,755 to construct 100 acres of artificial reef with coverage of 67% of the ocean bottom. This translate to an average annual cost of about$13000 per acre of reef habitat. Although no directly comparable to this analysis, the cost estimate shows what regulatory agencies might consider as being a "reasonable"cost for mitigating impacts to rock reef habitat in the Southern California marine environment. For comparison with the Recommended Plan, if you conservatively assume that the 100 acres of artificial reef created would provide prime habitat at or near the value of 1.0 HUs over the life of the restoration effort, the average annual cost for an artificial reef plan would be estimated to be $13000/AAHU. IP 5-26 Boulder Fields • Another confirmation of the reasonableness of the cost is reflected inP lans to construct a boulder field included in the authorized Federal authorized Santa Monica Breakwater Project. A separable feature included in the plan is to construct a one-half acre boulder field reef area at a first cost of$200,000. (It is noted that this cost does not include the cost for mobilization and demobilization). This boulder field reef cost reflects the cost of about 1,000 to 1,800 boulders placed at a depth of about-40 feet, see Figure 5-5, to provide artificial reef habitat of about 0.5 acres. The average annual cost of this plan is estimate to be about$16,000. Assuming that the ecology of the artificial reef would be of similar or equal value of the restored rocky habitat ecosystem created by the Recommended Plan, the average annual cost for the boulder field reef is estimated to be$32,000 per average annual habitat unit. Figure 5-5. Habitat Restoration Boulder Field . • •7 h p wr-..-____...z.r-4--=-1.-ecetzeo--.-"rz?-1:7 :. .. Let • • -. -. .a.- . . z • /• . sem `, t _ .•. �. %a • rCI ...M... . 4.:ti,1•raj(-...P. <:, /••t P• 91k . Oblique View 1`/ . ` / :...le : • Plan View K ) - . Q pi- ..1 -• I _1 - . 1.. •m'''+sand C �: 1. -crock • ;:"\H"!<'. - - •• '.) * .. 4441 meter -, 0 5-27 The scope and magnitude of such a restoration effort cannot be over emphasized. The amount of acreage being discussed would easily surpass the value of all nearshore artificial reefs or other mitigative programs in the Southern California Bight. Commerciallyimportant 9 P species such as abalone, lobster, urchins, white seabass, black seabass and rockfish (to name only a few)all are found on the peninsula. While rocky reefs encompass only 10% of the nearshore habitat in the bight, a restoration effort of the Palos Verdes Peninsula represents not only a potential fisheries increase, but also represents a greater potential to enhance stocks in other areas through natural recruitment and emigration processes. For example, black, green and pink abalone can still be found at Palos Verdes Point. Since we know that their larval/dispersal period is only a few days, the degradation of the benthic environment which we see will inhibit the recruitment of abalone to a large portion of the peninsula and slow the return of these stocks. Certainly we can also associate an economic increase for the sport fishing and sport diving industries with this project. Increasing the water clarity of this nearshore environment will immediately enhance the SCUBA diving opportunities from Abalone Point to Point Fermin providing a close to home option for the SCUBA diving interests based in Los Angeles Harbor. Thus, if we look at Palos Verdes in a pluralistic manner the importance of this habitat will go beyond any specific anthropogenic need. • 110 5-28