The Site C dam project in northeastern B.C. has spent $1.75 billion as of the end of May and is currently spending $60 million a month, BC Hydro CEO Jessica McDonald says.

McDonald and other BC Hydro executives briefed reporters Wednesday on the project, after an Tuesday between Premier Christy Clark, NDP leader John Horgan and B.C. Green Party leader Andrew Weaver.

McDonald provided details on Clark鈥檚 estimate that a delay in relocating two houses on the site on the Peace River near Fort St. John would create a 鈥渄omino effect,鈥� delaying construction of a realigned road and bridge that would lead to a one-year delay in diverting the Peace River to begin work on the dam foundation in the riverbed.

BC Hydro estimates show that delay would add $630 million to the cost of the project, including storage of turbines and generators, an additional year of site and environmental maintenance, and shutting down and restarting the main civil works contract.

McDonald said there is $4 billion spent or committed in existing contracts for the third dam on the Peace River, a system that already supplies a third of B.C.鈥檚 hydroelectric power. She would not comment on eventual costs of cancelling the project.

Horgan wants the Site C dam put to a review by the B.C. Utilities Commission. He said during the election campaign that does not mean stopping the project while the review goes ahead. After the minority government result and Weaver鈥檚 decision to support an NDP government, Horgan wrote to BC Hydro asking it to stop issuing new contracts and extend the lease on two houses set to be moved.

Weaver campaigned to have the project stopped. He attended the briefing at a Victoria hotel Wednesday, and said afterward the $4 billion cost estimate is a 鈥済ross exaggeration鈥� based on the assumption all contracts would be paid out in full.

McDonald wouldn鈥檛 comment on the scenario of cancelling the $8 billion project, which she said is a political decision. Her presentation detailed the fallout from delaying the relocation of two houses for realignment of Highway 29 along the Peace River, a project about to be tendered by the B.C. transportation ministry.

The house properties have been expropriated and if they are not moved to make room for the two-year road and bridge construction, that would trigger a one-year delay in the river diversion needed to build the dam foundation in the main channel of the river.