Blue Lake Expansion Project (Dams & Reservoirs)

Following in the footsteps of their forefathers, residents of the City and Borough of Sitka voted nearly unanimously – 97 percent ‘Yes’ – to end their dependence on imported diesel fuel and raise their local Blue Lake Dam to produce more hydropower. The small island community took a pro-active step toward securing its energy future when it approved a bond issue in 2012 to raise the 145-foot-tall 1950s-era concrete arch dam by 83 feet. Then our Team said “yes” to the challenges this project raised: the dam was built into a steep, narrow canyon with zero access on one side, which meant all equipment had to be delivered across the dam by crane, using the largest crane operating in Alaska at the time. That Liebherr 1600/2 crane also delivered tunneling equipment to the team building a drainage tunnel in the plunge pool and set a smaller crane in place on a flexi-float barge to allow our crews to work from upstream of the dam. Access to the top of the dam required design and installation of a steel-girded staircase embedded on a cliff wall and delivery of crews via manbasket and concrete via bucket.

Significant local talent was tapped in our work with subcontractors and suppliers, which is fortunate given Sitka’s island location and the barge delivery required for most materials. Partnering with the City and Borough of Sitka proceeded on many levels, from adjacent workspace in town to formal goal-setting Partnering sessions with stakeholders from all walks of life.

Barnard’s work on the Blue Lake project also appears in Tunnels, Hydropower, Environmental and Marine categories.

Blue Lake Expansion Project (Dams & Reservoirs)