during the disposal period (Fig. 9). During the postdisposal period, northerly 

 winds increased in frequency and speed. 



The experiment extended from a period of "summer oceanographic conditions" 

 into a period of oceanographic conditions more typical of the fall, winter, 

 and spring seasons (Fig. 10). The summer condition was characterized by south- 

 erly to southwesterly winds and a southerly swell direction. Winds during July 

 were commonly diurnal with a low-velocity breeze from the land in the morning 

 and a higher velocity, land-directed breeze in the afternoon. Breaker period 

 was typically less than 6 to 7 seconds and breaker heights usually less than 

 0.6 meter. The longshore current was northeast, toward the inlet, with an aver- 

 age measured speed of 18 meters per minute. 



The "winter oceanographic condition" was characterized by northerly to east- 

 erly winds and a wave swell from the east. Breaker period was typically greater 

 than 6 to 7 seconds and breaker heights commonly > 0.6 meter. Longshore currents 

 were typically southwest at an average measured speed of 23 meters per minute. 

 A number of northeasterly storms occurred during September and October. Wave 

 data from Atlantic Beach, North Carolina (j^ 58 kilometers northeast of New River 

 Inlet) show an increased occurrence of storm wave conditions during the latter 

 part of the study period (Fig. 11). 



Dye studies indicated that the juncture between wave-induced currents and 

 strong tidal inlet currents was located near the outer margin of the ebb tidal 

 delta. The disposal area, 2 kilometers downcoast from New River Inlet, was 

 judged to be beyond any direct influence of inlet-associated tidal currents. 



2. Storms . 



The criterion for a storm wave condition is arbitrarily chosen to be the 

 occurrence of breaker heights in excess of 0.6 meter. More than 70 percent of 

 the measured breaker heights were less than 0.6 meter (Fig. 7). The time-se- 

 quence LEO plot for the study area shows well-defined periods of relatively high 

 breakers (> 0.6 meter). These storm periods represent swell and local sea con- 

 ditions--the local sea usually being a response to extratropical storms or more 

 extreme summer (southerly) winds. 



Local seas of the summer diurnal wind period produced maximum average ^breaker 

 heights between 0.6 and 0.8 meter. These waves approached generally from the 

 south. Waves from the northeast, e.g., those associated with northeasters, pro- 

 duced maximum average breaker heights between 0.9 and 1.5 meters. Wave gages 

 located approximately 58 kilometers north (Atlantic Beach) and approximately 54 

 kilometers south (Wrightsville Beach) of New River Inlet showed that for a 4-year 

 period, maximum significant wave heights (recorded at water depth 'v 5.2 meters) 

 usually range from 0.9 to 1.8 meters in the summer and from 0.9 to 2.7 meters 

 in the winter. These wave heights represent the range in storm wave height 

 in the vicinity of the study area. Observed breaker periods for storm waves 

 at the study site ranged between 4 and 12 seconds depending upon whether local 

 sea or swell conditions existed. 



3. Wind-Driven Currents. 



Wind-driven currents occurred periodically and were effective throughout the 

 nearshore zone. For example, on 21 July during the summer diurnal wind period. 



