Hawaii (HDOT), has devoted special care to long-range planning. Plans and 

 concerns are described in the 2010 Master Plan for Kahului Harbor produced by 

 the State of Hawaii in 1994. A key concern is the possibility for expansion of 

 the harbor in concert with projected increases in population and economic activ- 

 ity. Wave activity at the existing piers during heavy northerly swells is also a 



Study Approach 



The study described in this report was performed by the U.S. Army Engineer 

 Waterways Experiment Station (WES), Coastal Engineering Research Center 

 (CERC), in support of the 2010 Master Plan for Kahului Harbor. The approach 

 consisted of the following components: 



a. Collect and analyze field wave data. 



b. Relate field data to long-term wave climate. 



c. Use field data to calibrate and validate a numerical wave model. 



d. Use the numerical model to investigate alternative harbor modification 

 plans. 



Field wave gages were installed outside the harbor and at four locations inside 

 the harbor. Locations for the harbor gages were selected with the aid of a pre- 

 liminary numerical model study of harbor oscillations (Okihiro et al. 1994). Two 

 events of special interest occurred during the measurement program. Intense 

 wave activity causing closure of the harbor occurred on 14-15 March 1994. A 

 sizeable (but not damaging) tsunami event due to an earthquake off the coast of 

 Japan occurred on 4 October 1994. The field wave measurement portion of the 

 study is described in Chapter 2. 



Long-term wind wave and swell climate was investigated primarily with 

 numerical hindcast information covering a period of 20 years. Statistics from the 

 gage outside the harbor were evaluated relative to the long-term climate. The 

 wave climate study is presented in Chapter 3. 



A numerical wave model was set up to cover the entire harbor and the area 

 outside the harbor extending to the wave gage. The model was tested, calibrated, 

 and validated, mainly using the field data. Nine alternative harbor plans were 

 defined as part of the mid-study model review conference, with provisions for 

 two additional plans to be specified after evaluating the initial plans. Thus the 

 study included a total of eleven plans and the existing harbor. All plans included 

 the following features: 



a. A 200-ft extension of Pier 1 toward the harbor entrance. 



b. A dredged area between Piers 1 and 3 to 35-ft depth to accommodate fuel 

 barges. 



Chapter 1 introduction 



