Beach Nourishment Techniques Report 1

This report presents the results of the first two phases of a research project aimed at developing new dredging systems for beach nourishment from offshore sources. As an introduction to the subject matter, the current situation in the United States regarding beach nourishment and offshore dredging equipment is outlined. Example nourishment projects accomplished and the range of equipment used to date. Next, the engineering considerations involved in selecting an optimum nourishment system for a particular project or project category are presented, and their effects on system characteristics are discussed. The main body of the report presents the results of an investigation into equipment suitable for offshore nourishment work. Approximately 50 examples are described illustrating dredge types, pipelines, connections, and miscellaneous pieces of equipment. The examples are divided into the main categories 'existing' and 'proposed' and subdivided according to design concept. The final portion of the report consists of the selection of certain equipment subcategories for further consideration and the construction of possible offshore nourishment systems using this selected equipment. A logic network is presented outlining these possible systems, and their projected uses are discussed. Future phases of the research project are outlined. The report includes approximately 45 illustrations and 85 references directly related to offshore dredging and beach nourishment. (Author).

Data are presented describing the average wave climate at 10 selected beach nourishment sites on the coastline of the continental United States: Reverse Beach, Mass.; Rockaway Beach, N.Y.; Carolina Beach, N.C.; Nassau County, Fla.; Dade County, Fla.; Treasure Island, Fla.; Panama City, Fla.; Redondo Beach, Calif.; Indiana Dunes, Ind.; and Presque Isle, Pa. The data were derived by calculating the effects of refraction, shoaling, and island sheltering on the deepwater wave climate applicable to each site. Deepwater wave climates were obtained from Synoptic Shipboard Meteorological Observation data tapes and California Department of Navigation and Ocean Development Files. Tables and plots of wave height/period frequency distribution on a monthly, annual, and azimuth of approach basis are presented as a means of summarizing the calculated data. The intent of this report is to provide information that can be used later to evaluate the ability of various offshore dredging systems to perform beach nourishment work. (Author).

This book is written for engineers, students of coastal processes and laypersons interested in beach nourishment, which consists of the placement of large quantities of good quality sediment on the beach to advance the shoreline seaward. The improvement of project performance through proper design and the predictability of performance are emphasized. The overall longevity of a project is addressed as are local erosional areas. The roles which wave height, project length and sediment quality play in project performance are addressed quantitatively. The results are illustrated through reference to a number of monitored nourishment projects. Biological and economic aspects of beach nourishment are addressed.