Imperial Beach Erosion Control Project San Diego County California Design Memorandum Number 4 General Design Memorandum

The authorized project provides for a system of five stone groins, the most northern groin about 600 feet long at the north end of the existing seawall at the naval radio station, and each of the other groins about 400 feet long and spaced at intervals of about 1,000 feet southward to a point 400 feet south of Coronado Avenue. The Corps of Engineers in 1959 constructed groin No. 1 upcoast from Carnation Avenue to a length of 600 feet; and 1961 groin No. 2 at Palm Avenue to a length of 740 feet. These groins did not function as expected, thus necessitating further investigations to develop an alternative plan for beach protection. The recommended project comprises: construction of a 5,000-foot-long breakwater at the minus 10-foot contour, extension of groin No. 1, and construction of a south groin. The benefits that would accrue to the Federal Government and the public from maintaining the recreational beach and protecting private and public properties justify the costs to the United States and to local interests.