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State of Washington Department of Ecology Agreement No: SEAFBD-2527-KICPWD-00022 Project Title: Upper Yakima River Floodplain and Habitat Restoration Implementation Recipient Names Kittitas County - Public Works Department agricultural economy, and provide open space acquisitions, the RECIPIENT and their partne Project. recreational opportunities. Building on the success of these rs have secured all additional lands needed to implement the As the river migrates and the Hansen Pits levee fails., salmonid, habitat becomes progressively diminished, and flood risk to public and private infrastructure increases. The RECIPIENT has worked with stakeholders to develop a conceptual design of the Project and initiated permitting discussions. This Project includes two main components, each of which will be described in more detail below: 1. Floodplain and off -channel habitat reconnection, creation, and enhancement through: a. Removal of a levee, berms', and other disconnecting features; b. Gravel pit and artificial pond restoration; and c. Floodplain recontouring and side channel creation. 2. Construction of new setback flood mitigation features. econnection, creation, Floodplain and off -channel habitat r and enhancement will include removing approximately A linear feet of levee and berm. Additional disconnecting feature rubble pile. Levee and berm r engagement at the I .5-y'ear recurrence interval. Removing these feature include r emoving a defunct headgate and concrete disconnected side channel habitat. s will als s that will be addressed t floodplain o neip restore access to emovai wiii targe Gravel pit and artificial pond restoration will enhance floodplain and off -channel habitat. The highest priority is the partial restoration of Hansen Pits, which currently prop ide habitat for warm water, predatory fish species rather than cold -water salmonids. A levee that separates Hansen Pits from the Yakima River i*s failing, allowing the Yakima River to migrate into the pits. Restoration of the pits will create a forested wetland habitat and side channel habitat that support native riparian communities. Floodplain recontouring accomplishes two main goals: 1) creating elevations suitable for riparian forests and 2) providing the needed sediments for gravel pit pond restoration. Reestablishment of riparian buffers will be obtained by recontouring floodplain elevations to facilitate connection at the 1.25 to 1.5-.-Year flood events and will incorporate side channel habitat. Actively, engaging the floodplain within the project area will improve aquatic habitat and reduce flood risk on the west floodplain across from the project site. A continuous corridor of riparian and side channel habitat will be established throughout the project area, providing essential rearing habitat for developing juvenile sal onids. These floodplain engagement activities will require setback flood mitigation features to address flood risk for the remaining private properties. Flood protection options are still being assessed, but will be provided by either elevating approximately 2,300 linear feet of the existing Stone Road, or by constructing a berm next to the road and by constructing a new setback berm along the eastern boundary of the County -owned lands or on the privately held lands. This additional setback berm could be up to 6,200 linear feet and may employ several disconnected berms. These berms will enable the project to meet both aquatic restoration and flood risk reduction goals. Overall Goal: The overall goal c�l�the project is to divest from failing flood infrastructure and restore natural riverine processes for the purposes of'creating, �iu�l i»aint.iining salmoni'd habitat, while allowing for flood -compatible uses and mitigating increases in flood risk directly associated with the project. Specific habitat restoration goals include Template Version 12/10/2020 Page 2 of 24