Planning and Design of Coastal Facilities

Harbors

Marinas

Breakwaters

Shore protection structures

Submarine Pipelines

Route reconnaissance studies

Design of protection and anchoring

Supporting oceanographic studies

Numerical Plume Modeling

Beach and Shoreline Analyses

Evaluation of coastal processes            

Beach-Renourishment                                                                                                           

Investigation of offshore sand resources

 

Sand Survey, West Maui (1997)

Sea Engineering is in the process of conducting sand surveys for resorts off the west side of Maui. Surveys include side scan sonar, grab samples, towed video, and diver coring. 

Client:  

Various

Rota Harbor Master Plan Island of Rota, CNMI (1997)

SEI, as a sub consultant to EFC Engineers and Architects, Inc., provided coastal engineering services for preparation of the Rota Harbor Master Plan. The project involved analysis of oceanographic design parameters, evaluation of alternative to harbor layouts and configurations, design of general navigation features and protective structures, and layout of new dock facilities.

Client: Commonwealth Ports Authority, CNMI

Ofu Harbor was originally constructed by the U.S. Army Corps of Engineers in 1975. In February 1990 the harbor was severely damaged by Hurricane Ofa, and before repairs could be made, Hurricane Val in 1991 completely destroyed the rock rubblemound breakwater. SEI was responsible for the basis of design analysis and preparation of construction plans and specifications for the complete reconstruction of the harbor. Armor stone of the required size was not available for construction of the breakwater, and so tribar concrete armor units were utilized, with the breakwater crest stabilized by a cast-in-place concrete rib cap.

Client: U.S. Army Corps of Engineers, Pacific Ocean Division

Palau Capitol Relocation Project Ocean Outfall Design (1996)

SEI was responsible for route selection and design of a new wastewater outfall on the island of Babelthaup, Palau. The outfall was required as part of the infrastructure for the new capitol of Palau. Work included: 1) underwater reconnaissance to locate the optimum pipeline route through irregular underwater terrain; 2) field investigation and analysis of water quality and circulation; 3) analysis of alternative discharge depths and configurations, modeling of initial and secondary dilution, and water quality assessment to determine the zone of mixing; 4) determination of oceanographic design criteria, development of pipeline protection alternatives, and conceptual outfall design.

Client: Architects Hawaii, Ltd., Honolulu, Hawai`i

Restoration of the Sand Island and Barbers Point Ocean Outfalls, Honolulu, Hawai`i (1994)

As subconsultant to SSFM Engineers, Inc., Honolulu, Hawai`i, SEI was responsible for an inspection and damage assessment for the entire Barbers Point Ocean Outfall, and the portions of the Sand Island Outfall in water depths exceeding 100 feet. The inspections and videotaping were completed using a manned submersible for the deeper areas, and SCUBA divers for the shallower areas. The damage assessment included determination of cause of damage, calculation of volume of protective rock lost, adequacy of armor stone size, and recommendations for repair. Associated work involved hindcasting site-specific waves associated with two recent hurricanes, calculation of near bottom wave induced velocities, and determination of worst case conditions.

Client: Department of Wastewater Management, City and County of Honolulu

SEI, in association with Olsen Associates, Inc. of Jacksonville, Florida, conducted reconnaissance-level coastal engineering investigations to identify candidate sites in Hawaii for the development and construction of a beach nourishment demonstration project(s).  Sites on the islands of Oahu and Maui were investigated. The study report describes the rationale behind the site selections, the nature of each site’s erosion history, the layout of the proposed beach restoration, the probable material quantities and costs for construction, and the scope of tasks required to implement the project(s).

Client: State of Hawaii, Department of Land and Natural Resources

Kaumalapau Harbor is located on the island of Lanai. This small, privately built barge harbor is protected by a rock and concrete rubblemound breakwater which has been virtually destroyed by storm waves. The breakwater is in 50 to 70 feet of water, and directly exposed to storm waves from the south clockwise to north-northwest. Repairs to the breakwater are to be made prior to the State of Hawaii incorporating the harbor into the Statewide harbor system. SEI is finalizing the design analysis, and preparing construction plans and specifications for rebuilding the breakwater. The design requirements are somewhat unique in that the breakwater is in deep water, thus has the potential for direct impact by very large storm waves, and it must be constructed on top of an existing rubblemound. Due to the size of the design wave, which results in the need for armor greatly exceeding any available stone size, Core-Loc concrete armor units are proposed for the armor layer.  Our work also includes preparation of an environmental assessment, and Federal and State permit applications.  

Client: U.S. Army Corps of Engineers, Honolulu Engineer District

Aerial Photographic Analysis of Coastal Erosion for the Islands of Kauai, Molokai, Lanai, Maui and Hawaii (1991, with Makai Ocean Engineering, Inc.)

Historical aerial photographs were used to determine erosion/accretion rates along 66 miles of sandy shoreline on five islands.  The photographs were corrected for tip, tilt and distortion, and rectified to either orthophotographs or planning maps. The results of the computer analyses were supplemented by site visits to allow evaluation of ongoing shoreline processes.  A statistical model was developed which utilized the historical data to predict future beach changes, and the confidence level of the predictions. 

Client:  Office of State Planning, Coastal Zone Management Program