washington

BURBANK, WA – The US Army Corps of Engineers, Walla Walla District has completed assembly on the second of three new advanced-designed hydroelectric turbines and begun its installation at Ice Harbor Lock and Dam.

According to the Corps of Engineers, these turbines will be safer for fish, reduce maintenance costs and increase power generation efficiency by 3 to 4 percent. Final turbine and generator installations are expected to take about 5 months with final commissioning scheduled for summer of 2022.

“The turbine is essentially the propeller that is rotated by water pressure to produce hydroelectric power,” said Project Manager Kevin Crum. “The adjustable blade turbine is fabricated with stainless steel blades that will resist corrosion and eliminate damage compared to the original carbon steel turbines. The new turbine units will utilize greaseless bushings and added improved seal technology to reduce infiltration into the river.”

The first of the 3 new turbines, a fixed blade turbine, was installed in Ice Harbor Dam in 2018. The second turbine, set into position on February 17, is an adjustable blade turbine runner that features adjustable turbine blades that can pass a wider range of water flow through the unit.

The original $73 million contract awarded to Voith Hydro Inc. included installing turbine replacements for three turbines — one fixed-blade runner and two adjustable blade runners – with the goal to improve the hydraulic flow conditions in the turbine water passageway. Field tests indicate significant hydraulic improvements to the flow conditions through the fixed blade turbine, and biological testing using balloon tagged fish in October 2019 resulted in a 98.25% direct survival rate.

The Corps anticipates the adjustable blade runner will have similar direct survival results when tests are conducted in the fall of 2022.

Ice Harbor Lock and Dam, located on the lower Snake River near Pasco, Washington, was constructed in the late 1950’s. Its first three hydro-turbine units were brought on-line in 1961 and three additional hydro-turbines became operational in 1976.

As the trio of 1961-vintage hydroelectric turbines approached the end of their design life, the Bonneville Power Administration and Walla Walla District recognized a window of opportunity to improve passage conditions for fish.

“After 50 years of operation and increasing maintenance requirements, the need to replace the existing turbines at Ice Harbor presented the opportunity to pursue new turbine designs with fish passage improvement as a priority,” said Martin Ahmann, Hydraulic Engineer and Technical Lead for the turbine replacement project.