doi:10.3850/978-981-08-7920-4_S2-C01-cd

ABSTRACT

Shipping operations on the island of Maui, Hawaii are suffering operational challenges due to ocean wave energy entering the Kahului Commercial Harbor during large winter swells. The State of Hawaii Department of Transportation Harbors Division plans to mitigate the wave problems inside the harbor by adding extensions to the breakwater structures at the harbor entrance at an estimated cost of US $140 million. A U.S. Army Corps of Engineers analytical evaluation on several proposed breakwater configurations concluded that breakwater extensions would not sufficiently protect the harbor from wave induced problems. This paper evaluates the technical and economical feasibility of constructing a submerged reef offshore from the harbor as an alternative means to mitigate the wave problems. The engineered structure will protect the harbor by focusing, rotating and dissipating wave energy before it reaches the harbor entrance. This evaluation compares the designs, construction techniques and costs of existing engineered reefs and estimates the cost of building the proposed reef at Kahului. The analysis concludes that an engineered reef with a volume of 100,000 cubic meters may provide sufficient harbor protection at a cost ranging fromUS $5 to $31.2million depending on the materials and methods used for construction.

Keywords: Coastal engineering, Artificial reef, Submerged structure, Wave modeling, Breakwaters, Cost analysis, Marine habitat, Kahului, Hawaii.

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