Replacement of Tsunami-Damaged Crescent City Marina

Abstract

This paper discusses the devastating effects of tsunamis on the Crescent City Harbor District's marina and the District's efforts to recover from the tsunami and replace the marina with a new tsunami resistant marina. The main marina in the harbor at Crescent City, California was badly damaged by a tsunami in 2006. Rather than simply rush to put back the marina the way it was, the District elected to design a replacement harbor to be as tsunami resistant as feasible. While the design process was underway, the March 2011 tsunami struck the harbor, hurt the fishing industry and threatened the local economy. The 2006 and 2011 tsunamis caused about $50 million damage to the waterfront structures and navigable waterways at Crescent City. The local fishing community marina was severely damaged and required replacement. The occurrence of two tsunamis so close together in time illustrates the importance of including tsunami effects on the design of this marina. Marinas are historically designed to resist operational vessel loads due to berthing, wind, wave, and current. The Crescent City marina is the first marina designed specifically to resist a significant tsunami wave. The author and his colleagues discuss the harbor damage from tsunamis, the emergency response plan, the design approach for the replacement marina and rock slope protection, the regulatory, permitting, and anticipated construction issues. The design process includes geotechnical constraints, hydrodynamic analyses, and float and pile design. This paper also discusses the cost effective means to optimize float and pile design, improve the recovery time for future tsunami damage, tsunami design lessons learned, and a path forward for future marina tsunami design. BACKGROUND Crescent City is located in northern California near the Oregon state border. The port had its beginnings in 1855, with the first wharf built on Whaler Island followed by initial construction of the Outer Breakwater by the Corps of Engineers in 1920 and the Inner Harbor and Marina in 1972. Commercial and sport fishing boats operate out