Imperial Beach, California, Design of Structures for Beach Erosion Control; Hydraulic Model Investigation.
Abstract
A 1:75-scale (undistorted) hydraulic model, reproducing approximately 2.6 miles of shoreline and sufficient offshore area to permit generation of the required test waves, was used to investigate the arrangement and design of alternative proposed structures for prevention of erosion of the Imperial Beach shoreline. The proposed structures consisted of (a) continuous breakwaters at the -15 ft and -10 ft contours, (b) segmented breakwaters at the -15 ft and -5 ft contours, (c) stepped breakwaters at the -10 ft and -5 ft contours, (d) a system of five groins, and (e) a system of nine groins. A 115-ft-long wave generator, crushed coal tracer material, and an automated data acquisition and control system (ADACS) were used during model operation. It was concluded from model test results that: Existing conditions are characterized by strong rip currents and longshore currents for most wave conditions with considerable onshore-offshore movement of sand; The original improvement plan for Imperial Beach (i.e., the authorized five-groin plan) is ineffective in trapping tracer material, and, in fact, contributes to the offshore movement; The originally proposed breakwater plan (Plan 1) is not adequate for full protection of the beach. Of the plans tested, Plans 3A, 4A, 5A, 5B, and 7 provide adequate beach protection.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1977
- Accession Number
- ADA044108
Entities
People
- Charles R. Curren
- Claude E. Chatham Jr.