Robert A. Walker, P.E.

Principal, Coastal Engineering

Robert A. Walker, P.E. Principal, Coastal Engineering

Mr. Robert Walker is a highly experienced coastal engineer with 19 years of expertise in coastal and marine projects. He specializes in dredging and dredged material management, coastal analyses and studies, shoreline protection, the design of waterfront facilities, and nature-based coastal hazard mitigation. Mr. Walker’s proficiency goes beyond planning, design, and field investigations—he also excels in guiding clients through the complex regulatory permitting process, successfully securing local, state, and federal permits for numerous complex coastal projects. In addition, Mr. Walker brings valuable expertise in hydrographic surveying, sediment sampling and analysis, construction ...

Robert A. Walker, P.E.

Principal, Coastal Engineering

Coastal Resilience

Congressional Report on Coastal Shoreline Erosion, American Samoa, Guam, Hawai‘i, Northern Mariana Islands, Puerto Rico, and U.S. Virgin Islands Worked alongside a team of national experts to evaluate hazards associated with sea level rise and coastal erosion to road infrastructure located within U.S. Island jurisdictions (American Samoa, Guam, Hawai‘i, Northern Mariana Islands, Puerto Rico, and U.S. Virgin Islands).

Evaluation of Nature-Based Shoreline Stabilization in Saipan Lagoon, Northern Mariana Islands Saipan Lagoon, located off the west coast of Saipan in the Northern Mariana Islands, consists of a barrier reef backed by a broad, shallow lagoon and narrow calcium carbonate beaches. A recent U.S. Army Corps of Engineers (USACE) coastal storm damage reduction study had proposed construction of a 2-mile-long seawall as the recommended alternative to protect coastal infrastructure. Using funding from National Fish and Wildlife 2Foundation, provided coastal engineering expertise to develop nature-based approaches to shoreline stabilization within Saipan Lagoon. Project activities included conducting field investigations, developing conceptual design alternatives, participating in stakeholder engagement, assisting with the development of a master plan, and serving as a project liaison to USACE.

State Park Shoreline Restoration, Pierce County, Washington Evaluated potential restoration opportunities for aquatic and riparian habitat that has been affected by the presence of a wooden bulkhead and several wooden groins at two locations within the park. The objective that guided each alternative was reducing the number of artificial structures while protecting the upland recreation features of the park. The evaluation of alternatives included shoreline change and erosion mapping based on light detection and ranging (LiDAR) and aerial photography, wave hindcasting, and analysis of sediment transport.

Living Shoreline Project, Federal Point Boating Access, Fort Fisher, North Carolina Designed a rock sill breakwater in combination with coastal wetland plantings to provide a living shoreline concept, offering enhanced habitat and water quality benefits while ensuring adequate shoreline protection from the open southwest fetch of Buzzards Bay. Other services included planning and design to fill the existing upland basin and relocate the boat ramp to the south side of the site, capture and treat all stormwater runoff through a constructed wetland system, and dredge the new navigation channel. In addition to design, responsible for all coordination with regulatory agencies and securing all required permits from state and federal agencies.

Peninsula Beach Erosion Study, City of Long Beach, California Evaluated coastal erosion and summarized shoreline protection alternatives for the chronically eroding shoreline. The study provided an overview of coastal processes and an evaluation of both short- and long-term management schemes involving beach nourishment.

Wailuku-Kahului Wastewater Reclamation Facility Shore Protection, Maui, Hawai‘i Provided coastal engineering and environmental permitting support for this project, which involved shoreline protection of the existing wastewater reclamation facility. An existing rock revetment protects a portion of the site; however, due to lack of funding, the original project was never completed to its full intended extent. This project involved an evaluation of shore protection alternatives for the unarmored shoreline of the site, including beach nourishment, hardened structures, and a combination thereof. Provided support to the engineering team, coordination of geotechnical explorations, and regulatory coordination with USACE.

Climate Impact Assessment

Impacts of Climate Change on Human Health and Medical Infrastructure, Ocracoke Island, North Carolina Conducted site investigations, community and stakeholder engagement, research, and analysis to evaluate coastal hazard vulnerability on the barrier island community of Ocracoke, North Carolina. The project focused on impacts to public health and medical infrastructure. Led all aspects of the project and was the primary author of the final report, which included detailed analyses of existing climate and health risks, as well as mitigation strategies and funding opportunities for their implementation.

Assessment of Health Vulnerability to Climate Change, Florida Keys This project consisted of site investigations, stakeholder engagement, research, and analyses to assess the impacts of climate change to public health across the Florida Keys. Assembled a multidisciplinary team of scientists, engineers, physicians, and experts in disaster preparedness and emergency management, coordinated in-person site investigations and stakeholder engagement, as well as managed a team that collected extensive information about existing climate risks, infrastructure, and medical resources throughout the Keys. Also coordinated the development of the final report, which provided a detailed analysis of existing climate and health risks.

Climate Change Tool for Island Communities, Nationwide Led the development of a web-based tool to assess climate change preparedness and vulnerability for island communities at the healthcare facility level. Users of the tool are presented with questions that relate to climate change hazards, social vulnerability, medical vulnerability and preparedness, and facility or community vulnerability and preparedness. Inputs are then used to estimate the climate change hazard risk based on an equation that incorporates hazard probability, severity, vulnerability, and preparedness. Results are presented in summary graphs that plot the overall climate hazard risk as well as the individual components of vulnerability and preparedness. A second output page provides resilience strategies that are tailored to the site-specific information gathered by the tool.

Coastal Science

Ocean Outfall Evaluation and Design, New Hanover County, North Carolina Served as part of a team responsible for collecting oceanographic data, such as water current directionality, velocity, and tidal variations; performing water quality modeling to provide regulatory agencies with an impact analysis of the proposed discharge of water treatment plant effluent; planning and design of outfall structure; coordinating the NPDES permitting effort; and conducting public meetings to discuss the new outfall structure and its potential impact to various user groups.

Coastal Hazard Assessments, Various Sites, Oahu, Hawai‘i Provided coastal hazard vulnerability assessments for three similar-scoped projects located on the island of Oahu, Hawai‘i. One project site in Hau‘ula was provided to the prospective buyer in support of an oceanfront property purchase, and another in Kahuku provided insight with respect to a potential transfer of property. An expert testimony report was provided in support of a litigation case located at Sunset Beach.

Identification of Submarine Groundwater Discharge in the Pūpūkea Marine Life Conservation District, Oahu, Hawai‘i This project involved using unmanned aerial vehicles and fixed-wing aircraft equipped with thermal infrared cameras to collect sea surface temperature data within the tidepool area of the Pūpūkea Marine Life Conservation District on the North Shore of Oahu, Hawai’i. The locations and extent of submarine groundwater discharge were identified based on measured temperature differences between groundwater plumes and surrounding ocean waters, and comparison with field measurements of temperature and salinity. Led all field investigations, data analysis, and reporting.

Inlet Monitoring and Maintenance, New Hanover County, North Carolina Conducted hydrographic surveys, beach profile surveys, and aerial photography analyses for this migratory tidal inlet in southeastern North Carolina. Assisted in developing a final report of findings and recommendations for inlet management activities.

Beach Monitoring and Analysis, Holden Beach and Ocean Isle Beach, North Carolina Conducted cross-shore beach profile surveys in combination with hydrographic survey data and shore parallel survey transects at mean low water, top of berm, and vegetation line. Survey data were analyzed and merged to provide the local governments with an accurate depiction of existing conditions and a planning tool for moving forward with strategic coastal management initiatives.

Coastal Engineering

Hawai‘i Kai Marina and Entrance Channel Maintenance Dredging, Honolulu, Hawai‘i Provided coastal engineering, environmental planning, and regulatory permitting services to the Hawai‘i Kai Marina. Professional engineering services have included dredging design, soil and sediment investigations, coastal structure design, beach nourishment, and dredged material placement design documents for three upland sites within the marina. Served as the engineer of record for numerous initiatives within the marina, and led all regulatory permitting efforts with agencies such as USACE, Hawai‘i Office of Planning, and City and County of Honolulu, and successfully obtained multiple 401 water quality certifications from the Hawai‘i Department of Health. Additional services have included the management of all environmental compliance aspects for the marina’s in-water projects, construction management for coastal and marine construction, and hydrographic surveying.

Wave Analysis and Hydraulic Loading Study, Nags Head, North Carolina Provided extensive wave and water level analysis in support of a new oceanfront pier in the Outer Banks of North Carolina. Upon determination of desired design conditions, hydraulic loadings on pier components were provided to the structural engineer of record. Additional services included an evaluation for potential pile scour due to waves and currents.

South River Boat Basin Waterfront Improvement, North Carolina Provided marine engineering services for needed improvements to the North Carolina Division of Marine Fisheries’ South River Boat Basin. Facility improvements consisted of approximately 4,000 cubic yards of maintenance dredging in the basin, approximately 1,720 linear ft of roadway improvements to the facility, a new 15-ft-wide boat launch ramp, new mooring dolphin pile clusters, and a new 113 linear ft by 5-ft-wide timber access pier.

Coastal Engineering Study for Liquid Natural Gas Facility, Mozambique, Africa Served as the coastal engineer for a front-end planning study for a proposed liquid natural gas facility. Analyzed various considered alternatives to evaluate their impact on sediment transport and shoreline response at the site. Mitigation measures such as beach nourishment, coastal armoring, and site layout design were considered based on the potential for increase or decrease in erosion or accretion and associated mitigation in the form of shoreline protection or stabilization and dredging requirements.

Beach Nourishment Using Upland Borrow Source, Holden Beach, North Carolina Provided planning and permitting of a shoreline protection project using sand from an upland borrow source. Responsibilities included an evaluation of the suitability of the sediments for beach nourishment, volume calculations for the most suitable material, and regulatory permitting for these activities.

Dredging of Wharves A1–A7, B1–B3, and Drydocks 1–3, Pearl Harbor, Hawai‘i Served as design engineer for this maintenance dredging project, which provided maintenance dredging of critical berthing and vessel drydock areas. Due to elevated concentrations of contaminants of concern within the dredge footprint, careful design considerations were necessary to achieve the project requirements while avoiding cost-prohibitive environmental remediation.

Rhine Channel Contaminated Sediment Cleanup, Newport Beach, California Provided engineering design, cost evaluations, sediment investigations, and the preparation of contract and construction documents for this contaminated sediment cleanup project. The project involved the dredging of approximately 100,000 cubic yards of contaminated sediment with beneficial reuse via disposal at the Port of Long Beach for a slip fill development project, and the replacement of approximately 130 dock guide piles to ensure docks were stabilized with the post-dredge depths. As the project moved into construction, served as the onsite construction manager representing the City of Newport Beach as the primary point of contact throughout the duration of the project. The project, which was completed under budget and ahead of schedule, was the largest dredging project ever undertaken by the City of Newport Beach.

Morro Bay State Park Marina Maintenance Dredging, Morro Bay, California Served as engineer-of-record responsible for developing a cost-effective dredging program to remove shoaled material from within the navigation channel and recreational marina. Led the development of design drawings and technical specifications, and then led the bid advertisement and contractor selection process. As the project moved into construction, provided limited construction management services, including providing technical expertise related to contract specifications, and regulatory compliance monitoring and reporting.

Middle Harbor Redevelopment Program, Port of Long Beach, California Served as onsite construction management support for a demolition and dredging project at the Port of Long Beach. Worked alongside Port staff providing technical expertise on dredging and marine construction issues for this project. Served as a liaison between the designer, contractor, and Port to solve problems expeditiously and minimize cost increases related to changed conditions. Responsible for coordinating requests for information, contractor submittals, acceptance and payment surveys, and change order negotiation, among other duties.

Brisbane Marina and Entrance Channel Maintenance Dredging, Brisbane, California Served as engineer of record for this project, which involved dredging of 140,000 cubic yards of material from the entrance channel and marina. Dredged material was disposed of at the SF-11 disposal site within San Francisco Bay.

Rainbow Harbor Entrance Channel Dredging, Long Beach, California Provided engineering design and limited construction oversight for the removal of approximately 25,000 cubic yards of material from the entrance the harbor. The intent of this project was to improve navigation conditions in support of the TransPac sailing competition that departs from Rainbow Harbor each year.

Dredging and Sediment Management, Town of Ocean Isle Beach, North Carolina Provided geotechnical investigations, engineering design, regulatory permitting, and construction management services for two independent hydraulic dredging projects, which involved approximately 10 miles of residential waterway canals in southeastern North Carolina. Designed dredged material placement sites using artificial islands originally constructed by USACE. These efforts required an in-depth understanding of sediment characteristics, drainage patterns, and dewatering strategies to ensure water levels could be maintained at optimal levels during various stages of the project. In addition to leading the design, permitting, and regulatory coordination aspects of the project, administered the bid advertisement process and served as construction manager for the town. Other project elements included public presentations and responding to stakeholder’s concerns prior to and during the projects, documenting construction activities in the field, and ensuring that the contractor successfully upheld environmental constraints and project specifications.

Navigation Channel Shoaling Analysis and Rock Jetty Design, Cedar Island, North Carolina Performed a shoaling analysis and evaluated alternatives to minimize shoaling of the entrance channel at the public boating access area. Cost estimates and final recommendations for various alternatives such as advanced maintenance dredging, deposition basin and extension of the existing rock jetty were provided to the client, the North Carolina Department of Environment and Natural Resources. Responsible for all regulatory coordination and obtained all permits from state and federal agencies, and coordinated the public comment aspects of the project.

Keauhou and Honokohou Small Boat Harbors, Keauhou, Hawai‘i Provided engineering and permitting services for these two tsunami damage repair projects for two sites impacted by the March 2011 Tohoku tsunami. Project work involved repairs to the existing loading pier, crib wall revetment, seawall, and navigation hazards removal as well as miscellaneous repairs to upland infrastructure at the site. With extensive coral colonies present within the direct project impact area, managed marine biological surveys and the development of a suitable coral transplantation program. Responsible for obtaining the necessary permits and approvals from USACE, NOAA-National Marine Fisheries, and State of Hawai‘i Department of Health 401 water quality certification.

Marine Corps Base Hawai‘i Marina Improvements, Kaneohe, Hawai‘i Provided engineering and permitting support services for this project, which involved significant upgrades to the marina, including a new floating wave attenuator, new floating docks, and rehabilitated boat launch ramp.

Pier 200 Replacement, Haleiwa Small Boat Harbor, Haleiwa, Hawai‘i Provided environmental permitting services to secure the necessary state and federal permits and approvals for this project. In addition to securing the necessary permits with USACE, also managed the marine biological surveys for the project and provided an engineering evaluation of the proposed flexible mooring system for the project.

Public Boating Access Area, Morehead City, North Carolina Provided engineering design, permitting, and construction management services to the North Carolina Wildlife Resources Commission for significant expansion and site improvements to the public boating access facility. The project involved dredging of the navigation channel and launch ramp area, new boat launch ramp and dock construction, new parking and drive aisle layout, and onsite stormwater treatment through an innovative constructed wetland system.

Dredged Material Management

Dredged Material Beneficial Reuse Analysis, Figure Eight Island, North Carolina Gathered all existing data concerning native sediment characteristics along beach profile transects for Figure Eight Island and Hutaff Island, as well as dredged material deposited in USACE disposal islands along the Atlantic Intracoastal Waterway in North Carolina. Coordinated further geotechnical investigations of dredged material disposal areas and performed sediment compatibility analysis for beach nourishment using updated technical standards set forth by the North Carolina Division of Coastal Management.

Portlock Beach Beneficial Reuse of Dredged Material and Beach Nourishment, Oahu, Hawai‘i This project consisted of dredging the entrance channel to the Hawai‘i Kai Marina on Oahu, Hawai‘i, to restore navigable depths and beneficially reuse dredged sediment as a source for beach nourishment at Portlock Beach. Coordinated and conducted geological site investigations, topographic and hydrographic surveys, and led the engineering design, state and federal permitting, and construction management aspects of the project.

Kapalama Container Terminal, Honolulu Harbor, Hawai‘i Served on the design team and was responsible for coordinating geotechnical explorations, topographic and hydrographic surveys, and conducting additional field investigations of existing site conditions. Assisted with dredging design for approximately 400,000 cubic yards with dredged material disposal sites including upland disposal, slip fill at Snug Harbor, and offshore disposal at the South Oahu Ocean Dredged Material Disposal Site. Also led development of the site demolition plans, which included extensive research of the State of Hawai‘i Department of Transportation (HDOT) files, as well as numerous on-land and in-water investigations to better understand the existence of historical structures within the project footprint. Attended meetings with the owner on behalf of the design team and served as a liaison between regulatory agencies, the design team, and HDOT project staff.

Dredging at South Channel and Halawa Stream, Pearl Harbor, Hawai‘i Served as design engineer and assistant project manager for this maintenance dredging project, which consisted of restoring the required navigation depths. The project involved upland disposal of dredged material at a nearshore confined disposal facility for contaminated sediment, as well as open-ocean disposal at the South Oahu Ocean Dredge Material Disposal Site.

Marina Bay Yacht Harbor Channel Maintenance Dredging, Richmond, California Provided construction management services during this maintenance dredging project in addition to providing design services and the preparation of bid documents. Due to elevated PCB levels at the site, dredge areas were sectioned off with disposal at two locations in the San Francisco Bay depending on the level of contamination. This required careful coordination with the dredging contractor and regulatory agencies to ensure that material was properly disposed of in accordance with all permit conditions. The presence of eelgrass within the immediate vicinity of the dredge area required special coordination to delineate sensitive areas and establish a safe buffer between dredging operations to ensure these biological resources were not impacted. Assisted in reviewing contractor’s progress surveys, performing volume calculations, conducting weekly construction meetings, processing payment applications, responding to requests for information, and ensuring the target dredge depths were achieved in accordance with the owner’s expectations.

Sediment Investigation

Alamitos Bay Marina Contaminated Sediment Dredging, Long Beach, California Served as design engineer tasked with developing a cost-effective dredge plan for the Basin 1 marina in Alamitos Bay. This marina, which had not been dredged since initial construction in the 1960s, posed a variety of design challenges due to uncertainties with regards to existing structures. A well-planned field investigation provided sufficient information to finalize the dredge design with little impact to the project budget. Alternative analysis for a variety of dredge plans was carried out to achieve the desired balance between removing contaminated material to the levels required by the regulatory agencies, while negotiating existing structures and staying within the project budget.

Otay River Estuary Restoration Project Sediment Characterization, San Diego, California Authored the data needs assessment, sampling and analysis plan (SAP), and summary report, and implemented and managed all geotechnical explorations for this restoration project, which lies within the San Diego Bay National Wildlife Refuge. Based on the initial analytical results of samples collected in the Otay River and adjacent floodplain, assessed the vertical and horizontal extents of contaminants of concern throughout the site and recommended a secondary sampling strategy.

Planning and Permitting

Planning and Permitting New Floating Dock, Sand Island, Honolulu, Hawai‘i Provided environmental planning and regulatory permitting services in support of a new dock. Obtained all regulatory permits and authorizations in an expedited timeframe to meet small-vessel research priorities after the closing of the Snug Harbor facility, which included a Section 401 water quality certification from the Department of Health, city and county Shoreline Management Act permit, Section 10 permit from USACE, and coastal zone management federal consistency determination from the State of Hawai‘i Office of Planning. Other services included managing the shoreline certification survey, performing additional site surveys to evaluate coral impacts, and preparing a coral mitigation plan and best management practices plan.

Marina Rehabilitation, Kaneohe, Hawai‘i Provided environmental planning, regulatory permitting, environmental compliance, and limited construction management services for this project, which involved the rehabilitation of marina guide piles and floating docks. Permitting efforts included obtaining authorization from USACE and the Hawai‘i Department of Health (401 water quality certification). Biological assessments of marine species within the project area were provided pre- and post-construction to satisfy avoidance and minimization requirements as they relate to essential fish habitat evaluations with the National Marine Fisheries Service, and a mitigation plan was developed for the project due to the existence of the state-protected black-lipped oyster located on the existing docks planned for demolition. Additional services performed included pre-, during- and post- water quality monitoring and limited construction oversight.

Hilo Harbor Pier 2 and Nawiliwili Harbor Pier 1 Cement Pipeline Improvements, Hilo, Hawai‘i and Lihue, Hawai‘i Provided environmental planning, regulatory permitting, engineering design, and construction management services for these two similar-scoped projects in Hilo and Nawiliwili Harbors on Maui and Kauai, respectively. The projects involved the replacement of cement conveyance pipelines below Pier 1 in Nawiliwili Harbor and Pier 2 in Hilo Harbor, Hawai‘i. After securing the necessary environmental permits/authorizations, led the engineering design and worked with HDOT Harbors Division to also receive its approval to move forward with construction. As these projects moved into construction, provided limited construction management and oversight, including submittal review, site inspections, and final reporting to HDOT-Harbors.

Hickam Harbor Marina and Rainbow Bay Marina Site Improvements, Honolulu, Hawai‘i Supported the U.S. Navy for two projects at Joint Base Pearl Harbor-Hickam on Oahu, Hawai‘i. One project involved providing repairs to the floating docks at Rainbow Bay Marina, and the other consisted of the construction of two gangways at Hickam Harbor. Tasked with obtaining state and federal permits and approvals from regulatory agencies such as USACE and Hawai‘i Department of Health, as well as managing water quality monitoring and site surveys related to sensitive marine species.

Ala Wai Small Boat Harbor 600 Row Finger Pier Repairs, Honolulu, Hawai‘i Provided environmental planning, design and engineering, bid advertisement, and construction management for this project. The project included a total of six new aluminum fixed piers for vessel berthing. Additional improvements included raising landside abutments to match the new pier elevations (which have been elevated for future sea level rise) and repairs to the adjacent mooring piles. This project required approvals from USACE and a blanket 401 water quality certification from the Department of Health Clean Water Branch. In addition, provided a marine biological survey for the project.

Site Investigation and Soil Remediation

Kekaha Multimaterial Recycling Facility Soil Sampling and Analysis, Kekaha, Hawai‘i Led the development and implementation of a SAP for site soils characterization in support of the proposed multimaterial recycling facility located in Kekaha on Kauai. The purpose of the SAP was to present an approach for site soil investigations to document existing (background) conditions at the site with respect to any legacy contamination that may be present. The SAP presented the proposed methods for carrying out the sample collections, laboratory testing and analysis, quality assurance and quality control, and reporting requirements. With the SAP approved, led field sampling activities, coordinated laboratory analyses, and provided final reporting of results to regulatory agencies.

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