The earthfill dam at Site C is starting to take shape on the Peace River, BC Hydro says.
Construction on the dam began on the north bank of the Peace River in October, ahead of its scheduled start in 2019, and is expected to carry on through to 2023.
BC Hydro tweeted a photo of what it called a "first look" at the dam on Nov. 26, which will stand 60 metres high, and stretch for a kilometre across the river. The dam will be nearly half a kilometre at its base, and is being built with a core of impervious material made up of clay and silt called till, officials say.
"The outer shell will be comprised of sands and gravels and the top portion of the dam upstream will be protected from wave erosion with riprap," project spokesman Dave Conway said. The dam will also include two filter/drain layers made up of processed sand and gravel, he said.
Materials for the core of the dam will be sourced from BC Hydro's industrial lands on 85 Avenue. Sand and gravel being used in the filter/drains and shell will be sourced from areas in the vicinity of the dam site. Riprap will be obtained from West Pine Quarry.
Peace River Hydro Partners is carrying out the dam's construction under a $1.8-billion civil works contract.
The Peace River is scheduled to be diverted starting in 2020 for construction of the earthfill dam to begin in the riverbed.
Site C is the third dam being built on the Peace River, and has been under construction since July 2015 after being approved by the BC Liberals at a cost of $8.8 billion.
The new NDP government allowed construction to continue in December 2017 after a four-month regulatory review, and bumped up its budget to $10.7 billion.
Site C's first turbine and generator are scheduled to be online in 2024, while the project is scheduled to be completed in 2025, producing up to 5,100 gigawatts of energy per year and add 1,100 megawatts of capacity to the provincial grid.
It would also flood some 100-plus kilometres of the Peace River valley and its tributaries, including farmland and First Nations cultural sites.
In October, the B.C. Supreme Court refused to grant an injunction to Treaty 8 First Nations looking halt construction on Site C until a civil trial could be held to determine whether the project infringes aboriginal treaty rights. The Supreme Court justice ruled construction could continue on Site C but that the courts must hear the treaty rights trial by by mid-2023.
There were more than 3,700 workers on Site C in September, the latest available labour data for the project. Those totals have come down by about 300 in recent months due to seasonal layoffs, mainly in concrete work that can only be carried in a five to six-month window before cold temperatures set in.
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