Results 



In evaluating test results, the merits of the improvement plan were 

 based on an analysis of measured wave heights in the harbor entrance. 

 Model wave heights (significant wave heights or H 1/3 ) were tabulated to 

 show measured values at selected locations. Wave heights in the jettied 

 entrance also were plotted graphically versus various wave conditions to 

 show the impact of the offshore breakwater. The impact of the improve- 

 ment plan on long-period wave conditions was determined through fre- 

 quency response curves (response factor versus wave period), and the 

 general movement of riverine sediment tracer material and subsequent de- 

 posits was shown in photographs. Arrows were superimposed onto these 

 photographs to depict sediment movement patterns. 



Short-period wave-height tests 



Results of short-period wave-height tests conducted for existing condi- 

 tions are presented in Tables 4-13 for test waves from the five directions 

 with the 0.0- and +7.0-ft swl's. For the 0.0-ft swl, maximum wave 

 heights 1 were 12.2 ft in the entrance (Gage 1) for 17-sec, 28-ft test waves 

 from west; 27.1 ft at the proposed breakwater location (Gage 9) for 17-sec, 

 22-ft test waves from northwest; and 28.7 ft at the alternate breakwater lo- 

 cation (Gage 5) from 17-sec, 20-ft test waves from west. For the +7.0-ft 

 swl, maximum wave heights were 15.2 ft in the entrance for 13-sec, 22-ft 

 test waves from west-northwest; 30.9 ft at the proposed breakwater loca- 

 tion for 17-sec, 28-ft test waves from west-northwest; and 30.3 ft at the 

 alternate breakwater location for 1 3-sec, 20-ft test waves from northwest. 

 For waves of 14 ft or less (operational waves), maximum wave heights in 

 the jettied entrance were 9.7 ft for 15-sec, 14-ft test waves from west- 

 northwest and 17-sec, 10-ft test waves from west with the 0.0-ft swl. For 

 the +7.0-ft swl, maximum wave heights in the entrance were 13.7 ft for 

 17-sec, 14-ft test waves from west-southwest and 13-sec, 14-ft test waves 

 from southwest for waves of 14 ft or less. Typical wave patterns obtained 

 for existing conditions are shown in Photos 1-20. 



Short-period wave-height test results conducted with the offshore 

 breakwater plan installed are shown in Tables 14-23 for test waves from 

 the five directions with the 0.0- and +7.0-ft swl's. For the 0.0-ft swl, max- 

 imum wave heights were 11.3 ft in the entrance for 19-sec, 22-ft test 

 waves from west-northwest; and with the +7.0-ft swl, 14.6 ft in the en- 

 trance for 15-sec, 30-ft test waves from west-northwest. For operational 

 wave conditions (14-ft waves or less) maximum wave heights were 9.0 ft 

 in the entrance for 15-sec, 14-ft test waves from west-northwest with the 

 0.0-ft swl; and 9.3 ft in the entrance for 1 1-sec, 14-ft test waves from west 



Refers to maximum significant wave heights throughout report. 



20 



Chapter 4 Tests and Results 



