AIRPORT LEVEE BANK STABILIZATION
Port of Willapa Harbor, Washington

The Port of Willapa Harbor airport facility flood control levee's tide gates suffered extensive bank erosion impacts during December 2007 storm events. Stabilization of the levee bank and existing tide gate structures were required to protect the levee from future erosion and breaching which would inundate the airport with Willapa River flood waters. After reviewing project site conditions, FEMA concluded that damage repair would qualify under FEMA disaster relief funding. The goal of the emergency repair was to protect approximately 1.7 miles of levee at the Port’s airport property located adjacent to the Willapa River. Coast & Harbor Engineering (CHE) conducted feasibility, preliminary and final engineering to develop a preferred alternative for stabilizing the levee bank at the locations requiring emergency repair determined by a FEMA/PORT/CHE site visit in February 2008. Construction was completed in 9/2009.

Pre-Construction, 5/2008	Post-Construction, 9/2009

CHE performed the following project tasks:

		Collected existing data and site information required for development of feasibility level engineering and permit drawings.
		Performed a site visit condition assessment and developed a master site plan illustrating the location and length of repair work required for each area.
		Evaluated levee stabilization alternatives and developed repair options for the existing tide gates.
		Developed design criteria including levee design requirements, design storm conditions and design life use to size stone for revetment.
		Conducted coastal engineering analysis to finalize locations requiring armoring.
		Provided plans, specifications, and cost estimates as well as bidding and construction oversight services.