McNary National Wildlife Refuge Design

The Confederated Tribes of the Umatilla Indian Reservation (CTUIR) is partnering with the US Fish and Wildlife Service (USFWS) to develop conceptual designs for an instream and floodplain restoration project on the McNary National Wildlife Refuge - Wallula Unit. The project is located on the Walla Walla River and will encompass up to 5 river miles and 1,200 acres of floodplain.

The primary habitat targeted by this project is riverine, floodplain, and riparian habitat. This project will identify and develop opportunities to remove confining features to encourage restoration of river processes, reconnect floodplain and increase channel complexity, and revegetate disturbed areas with native vegetation to improve the riparian area for fish and wildlife species. Priority fish species supported by this project include Middle Columbia summer steelhead, bull trout, and reintroduced spring chinook. The guiding documents that will inform the project are the CTUIR River Vision (2008), the McNary National Wildlife Refuge Comprehensive Conservation Plan Management Direction, and the Lower Walla Walla river Watershed Assessment.

The goal of the project is to improve natural river processes that will lead to: Increased channel complexity, with channel morphology closer to historical, functional form
Increased quantity and quality of native fish habitat, especially large wood and pools;
Improved sediment sorting and routing;
Increased stream velocity diversity at a range of high and low flows;
Increased in-stream thermal diversity throughout the year;
Increased floodplain connectivity and frequency of inundation; and
Increased riparian function with site-appropriate native vegetation. Design elements to support this goal include; selective levee removal, placement of large woody debris and boulders both in-channel and on the floodplain, construction of large woody debris jams, floodplain and side channel reconnection, and revegetation of disturbed areas on the floodplain. These actions will support adult overwintering bull trout (Salvelinus confluentus), migrating and rearing steelhead (Oncorhynchus mykiss), and migrating and rearing reintroduced Spring Chinook (O. tshawytscha).