Walla Walla District of the US Army Corps of Engineers (USACE) in Washington state has awarded ge-hydro a contract to design a fish friendly turbine. GE is one of four manufacturers to be awarded contracts totalling US$750,000, and the successful design may be used to upgrade all turbines at USACE’s McNary power house on the lower Columbia river in Oregon.

Completed in the 1950s, McNary is part of a project that comprises a 2.2km long dam and power house consisting of 14 Kaplan turbines each rated at 70MW and producing 8.7B kWh of hydroelectricity annually.

In the first of a three-phase award process, GE Hydro will design, manufacture and test a fixed blade hydraulic model turbine with fish friendly features such as optimised water passages and reduced runner blade gap.

Equipment for the model test phase, which will take six to eight months to complete, will be built and tested at GE Hydro’s laboratory in Quebec, Canada. Model drawings and components will then be submitted to the US government and independent laboratory testing facilities for further trials.

USACE will select one of the models by January 2004 and award a second phase contract to build a full size prototype turbine. Following installation at McNary power house, it will be tested extensively for efficiency, output and fish friendliness for up to two years. Success in phase two could result in contracts for the upgrade of the additional 13 hydro turbines at McNary.

The McNary dam is among a succession of dams on the Columbia river that must be navigated by salmon during their annual downstream migration to the ocean. The project is part of the USACE’s ongoing effort to improve survival rates of fish passing through federal hydro power dams.

Estimates suggest that the project could also increase electrical output by 15% under average water conditions if a full complement of 14 modernised turbines are installed. No significant investment has been made to improve efficiency since the turbines began operating in 1957.