Occurrences of Operational Waves from Hindcast Data 



Direction 



Total 

 Occurrences 



Occurrences 6-ft Wave Height Criterion 

 in Entrance is Exceeded 



Existing Conditions 



Offshore Breakwater 

 Plan 



Northwest 



13,295 



1,412 



1,607 



West-northwest 



16,416 



5,050 



2,729 



West 



4,536 



3,001 



1 ,952 



West-southwest 



991 



440 



72 



Southwest 



347 



230 







Total 



35,585 



10,133 



6,360 



Based on the hindcast data in Table 3, total occurrences with incident 

 waves of 14 ft or less were 35,585 for all five test directions. Occur- 

 rences in which the 6.0-ft wave-height criterion in the jettied entrance is 

 exceeded were 10,133 for existing conditions and 6,360 for the offshore 

 breakwater plan (based on wave heights obtained in the model). These 

 data indicate that for operational waves (14 ft or less) approaching from 

 northwest counterclockwise to southwest, the criterion is currently ex- 

 ceeded 28.5 percent of the time, and with the breakwater plan installed the 

 criterion will be exceeded about 18 percent of the time. The breakwater 

 plan will result in the entrance criterion being achieved 37 percent more 

 of the time for operational wave conditions than it currently is for existing 

 conditions. This is equivalent to about 23.5 days per year on the average. 

 In summary, the offshore breakwater plan will increase the amount of time 

 wave heights in the harbor entrance meet the 6.0-ft criterion; however, the 

 criterion will not be met for all operational wave conditions. 



For all operational wave conditions (14 ft or less) generated in the 

 model study, the values of the maximum wave heights in the entrance 

 were averaged for existing conditions and the offshore breakwater plan. 

 Average values per direction are shown in the following tabulation: 



Direction 



Average Values of Operational Waves 



Existing Conditions 



Offshore Breakwater Plan 



Northwest 



4.4 



4.6 



West-northwest 



5.1 



4.5 



West 



6.3 



5.0 



West-southwest 



7.7 



4.5 



Southwest 



7.4 



3.7 



Average 



6.2 



4.5 



22 



Chapter 4 Tests and Results 



