16-017 Corps awards turbine repair contract; turbine removed after 20 years

Published April 14, 2016

LOWER SNAKE RIVER, Wash. – The march toward modernizing the Corps hydropower facilities continued on Apr. 7, 2016, when workers at Lower Monumental Lock and Dam lifted the unit 1 turbine out of the turbine pit.

The U.S. Army Corps of Engineers Corps is the Nation’s largest hydropower producer and the Walla Walla District is the Corps’ 2nd largest hydropower producer.  The Walla Walla District awarded a $12.9 million contract to ANDRITZ HYDRO in July 2015, for generator winding replacement and turbine cavitation repairs to modernize the hydroelectric facilities at Lower Monumental Dam.

“It has been more than 20 years since Lower Monumental has had a turbine removed so it was a major event for us. The turbine removal was necessary in order to replace some broken hub linkage pins inside of the turbine that allow the blades to rotate,” explained Bryce Thompson, Chief of Tech at Lower Monumental Lock and Dam.


The 46-year-old hydroelectric power plant is located at the head of Lake Sacajawea, the reservoir created by Lower Monumental Dam. The dam is a run-of-river plant with six Kaplan-type turbines installed. The hydropower generator units 1-3 went online in May 1969, however no significant investments have been made to improve the reliability or increase the capability of the generating units since they were installed.

To maintain reliability, the aging turbines and the associated equipment have are being replaced or upgraded, taking advantage of the technology and information that has become available since the installation of the dam.

“The Corps’ power-generation infrastructure is aging, presenting an increased risk of reliability issues. As power-production components near and exceed their design-life, it is critical to replace these components with consideration to sustainability, the environment, while find better generation efficiencies,” said Jason Williams, Project Manager for the capital improvement project.

The work of the hub linkage upgrade of unit 1 at Lower Monumental involves the complete disassembly of the turbine runner, installation of government-furnished internal hub components and reassembly of the runner.

Turbine Runners:  The Critical Element in Modernization

The turbine runner is the critical component in the power train.  The runner determines the ultimate performance of the powerhouse and sets the stage for other improvements necessary in the rest of the plant to achieve reliability and efficiency benefits.  The turbine runner also plays a role in the fish passage through the project.

“Because of their location on the east side of the Cascades and the size of their generators, Washington State’s lower Snake River dams are also critical links in the carefully synchronized operation of the Northwest’s federal hydropower system,” explained Williams “Capacity is becoming increasingly important to the Pacific Northwest as loads continue to increase over time during the region’s periods of peak power demand. Hydropower’s flexible, reliable, responsive benefits cannot be replaced by other less-consistent renewable resources such as solar and wind,” continued Williams.

The entire project is expected to be complete by May 2017.

“Investing in the maintenance and operation of critical civil works infrastructure projects is an investment in the Nation’s economy, security and quality of life – now and in the future,” said Lt. Col. Timothy Vail, the Walla Walla District Commander.

For More Information


Further information and status updates are available on the web at: http://www.nww.usace.army.mil/Locations/DistrictLocksandDams/LowerMonumentalLockandDam.aspx





509-527-7020     cenww-pa@usace.army.mil      www.nww.usace.army.mil


Release no. 16-017