The rate of littoral drift at Sarits Barbara has been determined, to be 

 about 270,000 cubic jards a year. It irioves dovmcoast. This drift was 

 completely intercepted by a shore-connected breakT^ater, constructed in 

 1927. After its construction, the upcoast angle of the bre-kv;ater filled 

 in and material passed along and around the seaward end of the structure , 

 settling in the protected harbor area. The resultant shoal extended across 

 the harbor entrance to^rards shore. Coincident with the accretion 01 laaterial 

 in and upcoast of the harbor, erosion be^-aji on the downccast side of the 

 harbor. VJithin a period of 10 years, the erosion zone extended a distance 

 of 10 miles dovmcoast and the damage amounted to millions of dollars, 



I4I7. A project was inaugurated in 1935 for the maintenance of 

 navigable depths in the harbor entrance and the restoration of the doirm- 

 coast beaches by cooperation of the United States and the city and county 

 of Santa Barbara. The first dredging in 1935 was done by hopper dredge. 

 The material was deposited in lO feet of water in a mound parallel to 

 shore. It was hoped that the material xirould be moved ashore by wave action, 

 a hope that was never realized. Subsequent dredging has been accomplished 

 at 2 to 3 year intervals by hydraulic pipe-line dredge. In these operations, 

 amounts ranging from 500,000 to 800,000 cubic yards of material vjere 

 dredged and deposited directly on the beach downccast of the zone of 

 influence of the breakwater. i/Jithin a second 10-year interval the beaches 

 had been re-established and the shore line stabilized along its new aline- 

 ment. The action at Santa Barbara has adequately demonstrated the efficacy 

 of periodic by-passing of material to maintain normal littoral drift to 

 the dovmdrift beaches, 



[tl8. Two things are required for the effective use of floating plant 

 for periodic by-passing of sand: (l) a sand trap of sufficient size as to 

 retain littoral material between dredging operationsj and (2) a protected 

 area within which the suction dredge can operate in safety. Both con- 

 ditions were satisfied by the breakwater at Sarita Barbara, The Santa 

 Monica breakwater (see Figure 66) has provided similar protection, as well 

 as a sand trap, from which similar by-passing has been accomplished. 



14.19. In some few instances, dredging with fl.oating plant has been 

 attempted on the open coast by confining operations to calm periods. Even 

 so, much lost time has ensued and damage has been severe with the results 

 that contractors either submit high prices or no bids at all on this kind 

 of work. If conditions are favorable, consideration may well be given 

 to the construction of a combination sand trap and protective structure , 



SAND DUIMES 



U20, The problem of dune control resolves itself into two funda- 

 mental objectives: (l) the sta^bilization and maintenance of sand dunes 

 at locations where they exist naturally; and (2) the inducement of dune 

 formation where they do not exist naturally, by the direct and permanent 

 stoppage or impounding of sand before the location to be protected, and 

 the stabilization of the dune formation after its creation, 



202 



