Submerged breakwater protection at Kahului Harbor

Abstract

Due to the complexity of the coastal zone, traditional coastal protection measures such as seawalls, breakwaters, and groins have not always been entirely successful. The challenge of mitigating wave energy has proven difficult for Kahului Harbor on the North Shore of Maui, Hawaii. The existing method for reducing wave energy at Kahului Harbor uses direct protection in the form of emerged rubble mound breakwaters. Despite these protective measures, the harbor entrance is not trafficable during winter swells and causes shipping delays. Improvements in coastal protection technologies allow for consideration of reducing the high wave energy by employing submerged breakwaters to address this problem. Case studies of existing submerged breakwaters provide examples of various techniques used in the construction of these structures, allowing a review of the benefits, difficulties, and overall effectiveness of each. An emphasis is given to geotextile breakwaters as it is among the newest technologies in this application. To accurately examine work tasks and their associated resource allocation, a process simulation model is prepared in the CYCLONE simulation language, and entered into EZstrobe. Critical subtasks are identified to identify where efficiencies in resources could be gained. All submerged breakwater solutions should cost less, and work more effectively than the originally planned breakwater extension. Modeled methods are optimized to maximize the utility factor and conduct a cost-benefit analysis, which is included in the overall analysis of the alternatives for Kahului harbor.