With landward migration of the disposal bar, removal of the surf zone bar, 

 and filling of the inshore trough, a platform was created which widened the surf 

 zone. In some cases, a new trough was cut in this platform at the old surf zone 

 bar position. The development of such a platform maj^ provide additional beach 

 protection benefits by increasing wave energy dissipation in the surf zone. 

 Wave refraction around the disposal zone may also promote sediment accretion 

 landward of the zone, as in the case of offshore breakwaters; however, because 

 of the rapid removal of the disposal piles, this is only a short-term gain. 



Bottom changes for a distance of 60 meters seaward of the disposal site were 

 evaluated from the survey coverage. In a single case, between 16 September and 

 19 October, a period during which a number of minor to moderate coastal storms 

 occurred, the offshore area gained sediment. The offshore buildup is interpreted 

 to reflect shoreward accretion onto the disposal bar as well as longshore ex- 

 tension of the disposal bar. The seaward -displaced depth contours of the new 

 profile caused by the presence of the placed disposal material, appeared to have 

 promoted onshore transport. 



The disposal bar apparently served as a storm bar. Evidence indicates that 



in response to the mid-September storm, major transport was shore parallel along 



the bar axis and that sediment accreted on the landward flank of the bar and in- 

 shore of the trough. 



The occurrence of shore-parallel, wind-driven currents capable of transport- 

 ing sediment throughout the nearshore zone was documented. Wind-driven currents 

 apparently occur quite frequently, and, if flow is in the same direction as a 

 swell-induced longshore current, the resultant transport in the surf zone may 

 be higher than expected. It was not possible to judge the effect of wind-driven 

 currents on the disposal sediment other than to acknowledge shore-parallel trans- 

 port out of the disposal area both seaward of and within the surf zone in re- 

 sponse to such currents. 



41 



