Forrest Kerr Hydroelectric Project

Award-winning project harnesses the immense power of the Iskut River

AltaGas | Canada | 2011–2014

70,000
homes powered

195 MW
generating capacity

Award of Excellence
Canadian Consulting Engineering Awards

Tree of Life Award
Canadian Consulting Engineering Awards

Challenges

  • Construction was halted eight months in when it was discovered that the incumbent's design was not working.
  • Geotechnical challenges, including construction on unstable volcanic rock, required complex engineering solutions.
  • High levels of bedload and suspended sediment were carried in the river.

Solutions

  • We assumed responsibility for the final design eight months into construction. We successfully managed the transition of the design effort with the contractors.
  • The design of the powerhouse was completely overhauled, including an innovative turbine configuration that took the powerhouse from four turbines to nine and allowed for bypass while running at overspeed. This avoided the need to construct a costly additional underground flow bypass and energy dissipation system.
  • Successfully finalized detailed design of various critical elements while construction work progressed simultaneously by packing construction contracts into a number of smaller time- and material-based contracts.

Highlights

  • The local First Nations community was directly involved in the success of the Forrest Kerr project, providing a third of the construction workforce.
  • The project was ultimately delivered on time and on budget despite the initial design challenges.
  • An innovative sediment collection and flushing system was installed that is capable of flushing the equivalent of 1,205 dump trucks of material per day.

Project numbers

$725 millionproject
Nine 23.4 MWFrancis turbines
4.4 milliontonnes per year of sediment diverted
20,000 m3of loam recovered from excavation of the headworks used as conductive backfill to improve the ground resistivity of the 287 kV switchyard

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