| Contact: Nola Leyde, 206-764-6896 August 25, 2005 SEATTLE -- The U.S. Army Corps of Engineers began gravel nourishment and loose woody debris placement along the Green River one mile downstream from the City of Tacoma Diversion Dam at the construction site known as Zone 1 on Friday, Aug. 19. The Corps will place approximately 7,000 tons of gravels sized to meet Chinook salmon spawning needs in the two locations constructed in 2003. Afterwards, the Corps will place 30 pieces of marked large woody debris and five tons of small woody debris on the gravel berms. Markings will be used to identify wood from the project so that the number and locations of wood downstream can be monitored each year. Public access to the Zone 1 site will not be permitted during construction. Warning signs will be posted at the Zone 1 site and also at two riverside locations at the Kanasket-Palmer State Park. Fish habitat construction also began along 22 miles of the Green River above the Howard A. Hanson Dam, located upstream of the Tacoma Diversion Dam. All the work will be completed between Aug. 1 and Sept. 30 to avoid any construction impacts to fish in the upper Green River. During this time, crews will build some 37 engineered log jams at eight sites using a variety of methods. The engineered log jams will be stabilized using driven piles, which have been shown to be stable to the conditions in the Upper Green River, as well as cost effective compared to other methods. Approximately 700 pieces of large woody debris will be placed in the log jams. In addition, 160 pieces of loose woody debris will be placed in other locations in the river. The Green River Watershed is closed to the public. Both projects are part of the Howard A. Hanson Dam Additional Water Storage Project that will provide 20,000 acre feet of water for the City of Tacoma and their project partners when reservoir elevation is raised from 1,147 to 1,167 feet above sea level. The fish habitat construction is mitigation and restoration for the additional water storage according to the project environmental impact statement. Fish habitat rehabilitation under the Additional Water Storage Project began in 2003 when the Corps constructed two engineered log jams and initiated annual gravel nourishment. In August 2004, the Corps added an additional 7,000 tons of Chinook spawning sized gravels, placed more racking wood material on the upstream log jam, and placed three pieces of large woody debris on the upstream gravel berm. The Corps will continue to place wood and gravels for the duration of the project, which is 50 years. In 2006, the Corps will place loose wood five Green River tributaries and construct six more fish habitat projects above the Dam, as well as restore the Signani Slough side channel below the Dam. Under the biological opinions, issued by the National Marine Fisheries Service and the U.S. Fish and Wildlife Service, the Corps is required to transport half of all large woody debris meeting specific size criteria that is collected in the reservoir above Howard Hanson Dam and release it at downstream locations on an annual basis. Annual spawning surveys indicate increases in both the number of Chinook salmon and Steelhead spawning redds around the log jams and in the gravel nourishment reach. In October 2003, Corps biologists observed Chinook, pink, sockeye, and coho salmon using the newly created habitat. Spring monitoring surveys indicated that large numbers of fry were using the log jams as rearing and protection habitat. For online information, visit the project's Website at http://www.nws.usace.army.mil/PublicMenu/Menu.cfm?sitename=hhd_awsp&pagename=Pilot_Project_2003. For more information, contact Nola Leyde, public affairs specialist, at (206) 764-6896. |
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