As a part of the overall project to deepen the Port of Oakland’s shipping channels to 50 feet to accommodate larger vessels, Winzler & Kelly was selected as the prime consultant to design the repository site for approximately seven million cubic yards of dredged material. The dredged material is to be placed into the Middle Harbor, which was formerly utilized by the U.S. Navy. In order to contain the material, Winzler & Kelly designed a combined steel sheet pile wall and rock jetty containment structure. Once the material is placed, eelgrass will be planted on the site with the intent of attracting small fishes and birds such as the Least Tern.

The containment structure is approximately 3,700 feet long. The first 1,000 feet is a rock jetty with a 2:1 slope, varying in height from 46 to 36 feet. The rock jetty is composed of core rock with heavier two-ton armor rock providing wave protection. Steel sheet pile is then installed for the next 1,800 feet in water varying in depth from 40 to 10 feet. In the deepwater section, the sheet pile is composed of cellular ARBED units uniquely designed as a deep U-box to resist strong wave forces. The sheet pile in the shallower water is conventional AZ sections. Both structures are designed to withstand both static and dynamic forces including seismic forces from an earthquake of approximately 8 M Richter scale.