Patton Crk-Willapa Passage and Restoration Design

The Willapa Bay Fisheries Enhancement Group is proposing a project to create a design to restore the confluence between Patton Creek and the Willapa River to proper function through the removal of a barrier culvert, replaced with a full passage structure, and returning Patton Creek to its natural flow channel. Design will also fully develop plans to restore the lower portion reach of Patton Creek (.15 Miles) and the Willapa River (1.05 Miles).  This section of the project is referred to as the Lower Project Reach.   A separated design, the Upper Project Reach will also be developed for the restoration of the remainder of Patton Creek above the existing homesite (approximately 4 stream miles).  This section of the project is a significant opportunity to improve the spawning and rearing habitat for salmon and steelhead.  The design will incorporate elements to improve summer water flows and reduce stream temperature through development of cold water refuges.  In all project reaches, design elements will be directed towards improving stream complexity for both fish use and improved hydraulic performance during various flow stages in the system.  The division of the design project into these two project reaches was selected to allow clear transition into separate construction phase projects.     

There are several goals central to the proposed project. These goals include development of preliminary designs that if implemented, will accomplish the following: Restore free fish passage of all life stages throughout the project reach focused on the removal of a significant culvert barrier and developing its replacement at the confluence of Patton Creek and the Willapa River. Improve both the quantity and quality of available spawning habitat for coho, chinook and steelhead. Improve both the quantity and quality of available rearing/resting habitat, including side channels, pools, and stream complexity for coho, chinook and steelhead of all life stages. Project design will incorporate diversity of habitat along project reach. Increase summer water flows and decrease water temperatures through improved water storage capacity and development of cold water refuges through strategic placement of LWM to create pools and increase hyporheic exchange. Improved hydraulic performance during high water flows through development and connection with floodplain elements.