Representing the province in B.C. Supreme Court on Tuesday, lawyer David Cowie said it was the clear prerogative of the ministers to disregard a portion of the recommendations that came out of a provincial-federal joint review panel.
The panel held hearings and spent three years assessing environmental concerns around the $8.8-billion hydroelectric project to be built by Crown utility BC Hydro along the Peace River.
"Recommendations are advisory in nature," said Cowie, who described the environmental assessment process as a planning tool that focuses on identifying and mitigating a project's adverse impacts.
"Ultimate decision-making power lies with the ministers."
The Peace Valley Landowner Association is asking the court to quash the government's decision to approve the dam.
The megaproject would see more than 5,500 hectares of land along the Peace River flooded to create an 83-kilometre-long reservoir.
The landowner group's lawyer Maegen Giltrow argued in court on Monday that the environmental assessment process was flawed.
She said the government erred when it opted to ignore a number of recommendations coming out of the review panel that related to assessing total costs, alternative options and the overall need for the project.
She cited Environment Minister Mary Polak's dismissal of the recommendations as falling outside the scope of the panel's mandate.
"A decision cannot be reasonable if the decision-maker does not consider the factors the statute requires them to," she said, referencing a responsibility to review the recommendations as laid out in the Environmental Assessment Act.
Cowie called Giltrow's argument "very capable and genius," but said that it unfairly undermines the latitude of a minister's discretion.
Ministers are entitled to weigh the non-binding findings of an advisory body as they see fit and are ultimately accountable to the democratic process, he said.
On Monday, Energy Minister Bill Bennett waded into the case, reaffirming his government's commitment to start work on the dam by summer.
Opposition has dogged the long-range energy project over the decades, but that resistance has heightened in the past seven years since the project has been formally in the works.
This legal challenge is the first of seven expected over the coming months against both the provincial and federal governments from various groups opposed to Site C.
Treaty 8 First Nations are scheduled to appear in court with similar challenges against the province on Thursday.
When completed in nine years, Site C is anticipated to produce 1,100 megawatts of power annually, which is enough to power nearly half-a-million homes.
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