Bie other field research group, on the East Coastj is studying a 

 somewhat different kind of problem — the movement of a spoil bank of 

 dredged sand containing 6OO5OOO cubic yards in 38 feet of water. This 

 project was an experimental one to determine whether dredged material 

 from harbor channels dumped by hopper dredges, as close to the shore 

 as they could safely navigate, would eventually move in to the beach. 



The iump area is about 3,700 feet long by 750 feet wide and is 

 located about one-half mile irom shore, just north of the pier at 

 long Branch, New Jersey. The material was dumped during the spring 

 and summer of 194-8, and surveys were made by the field research group 

 before, during, and after the dumping opera tioj^So The surveys extend- 

 ed for four miles along the beach and for a distance of a little more 

 than a mile out to sea. Surveys of the entire area were made in April, 

 July, and October, with weekly surveys of the immediate dumping area, 

 weather permitting. 



On this section of the New Jersey Coast, the predominant littoral 

 drift is northward toward Sandy Hook, Onshore winds prevail about 60 

 per cent of the time. It was found that bottom velocities existed in 

 the dump area high enough to move the sand in the pile, but on com- 

 pletion of the fall survejrs no appreciable movement of the pile shore- 

 ward could be detected. About 21 per cent of the dredge bin measure 

 appeared to have moved outside the dump area, but the beach showed 

 little evidence of receiving enough sand to measure. The change was 

 in the nature of a flattening of the pile and some scattering of sand 

 in a thin layer away from its boundaries. 



TJie spring surveys completed in April are being studied now. 

 Detailed computations have just begun, and the general indication 

 is that a rather appreciable portion of the pile has been moved. The 

 beaches nearby appear wider in places to the casual observer, but we 

 cannot attribute any apparent improvement to the offshore sand bank 

 until we have made an exhaustive analysis of the data from the spring 

 surveys . 



In conclusion, it can be stated that ttie Board feels strongly 

 that the general investigative program will be of great benefit in 

 providing more economical, yet sound, solutions to individual coastal 

 erosion problems. The results of the research are made available 

 in publications of the Board and are applied to specific beach erosion 

 studies by means of consultation between personnel of the field 

 offices and the staff of the Board. 



