Book Description

This report presents results of Phase II of a study performed for the U.S. Army Engineer District, Seattle, to determine the technical feasibility of maintaining a reliable bar or entrance navigation channel into Willapa Bay, Washington. The study was authorized by the Seattle District in cooperation with the Port of Willapa Harbor under a Partnering Agreement. The Phase I study was an intensive effort to understand the physical processes at the study site, collect data, and establish numerical simulation models of the waves and currents at the entrance. Numerous alternatives for creating and maintaining the most reliable entrance channel were also identified and screened. The Phase II study describes the results of ongoing monitoring of the existing natural navigation channel, changes in bathymetry, and refinements to the numerical models. Also included is an application of the monitoring and modeling technology to the entrance channel leading from Willapa Bay to Bay Center, as small fishing harbor. The entrance area of this shallow-draft navigation channel served as a convenient surrogate for improving the predictive technology, as well as advancing understanding of sediment transport processes in the bay and the deep Willapa Bay entrance channel.