south jetty in 1958. The problem at Oceanside is one of shore recession 

 due to impoundment of the dominant southward littoral drift at the harbor 

 jetties. An existing Federal beach erosion control project provides for 

 artificial placement of beach fill on the Oceanside frontage. Although this 

 fill was partially placed in 1957-58 in connection with dredging Camp Pen- 

 dleton Harbor, erosion of the fill has been rapid because of the deficiency 

 of natural supply of material, and because reconstruction of jetties at Camp 

 Pendleton Harbor provided additional protected area for local impoundment 

 of beach material. Additional measures are desired to restore and maintain 

 an adequate protective and recreational beach along the city frontage. 



Ocean Beach, a part of the City of San Diego, is a short pocket beach 

 between the Mission Bay - San Diego River jetties and Sunset Cliffs. An 

 existing Federal beach erosion control project provided for placement of 

 beach fill in connection with dredging of the Federal navigation project for 

 Mission Bay and construction of one groin t . This work was completed in 1955. 

 No further work is required at this time. Imperial Beach is a residential 

 community on the ocean shore about 3.5 miles north of the Mexican border. 

 An existing Federal project provides for construction of five groins on this 

 shore frontage. The most northerly groin was constructed in 1959 in accord- 

 ance with the program of progressive construction from north to south. This 

 construction resulted in widening of the beach and indicates that completion 

 of the project will provide a satisfactory protective and recreational beach. 



The tides on the ocean shore of the study area have a diurnal inequal- 

 ity, the mean and diurnal ranges being respectively about 3.7 and 5.3 feet. 

 The maximum tide each year is about 7 feet above mean lower low water. 

 Characteristic waves are swells generated in distant ocean areas. They have 

 heights up to 10 feet and periods up to 20 seconds, with the greater heights 

 and shorter periods occurring in the winter. Winter waves generally approach 

 the shore from upcoast of normal, summer waves frequently approach from down- 

 coast of normal. On the ocean shores north of Point Loma at the entrance to 

 San Diego Bay, littoral drift is in general southward in winter and northward 

 in summer. In the Oceanside area southward drift is predominant, as indicated 

 by the general accretion north of the Camp Pendleton Harbor jetties and ero- 

 sion to the south. At Mission Beach and Ocean Beach the net annual movement 

 in either direction is negligible. South of Point Loma, the predominant 

 direction of drift is northward. At all ocean front areas there is also a 

 large seasonal onshore-offshore movement of material. 



The District Engineer concluded that localities which have had erosion 

 problems warranting remedial action are included in authorized Federal 

 projects; that the project for Ocean Beach being completed is serving effect- 

 ively at this time; and that the project for Imperial Beach is partially 

 completed and will apparently be continued to effective completion in accord- 

 ance with the project plan. He further found that certain modifications are 

 necessary in the existing project for Oceanside in order to provide for 

 changed conditions since the project was adopted and to revise the Federal 

 contribution toward the cost on the basis of equity. 



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