BC Hydro filed its Project Description Report Wednesday with provincial and federal regulators, initiating the environmental assessment phase of the proposed Site C hydroelectric project.
The report contains new baseline environmental impact information, updated engineering and, most controversially, an updated price tag - pegging the project's estimated expense at $7.9 billion, up from the $6.6 billion estimated in 2007.
BC Hydro's Community Relations Manager, Dave Conway, told the Alaska Highway News that the low 2007 estimate was based on an escalated project cost estimate of the 1981 designs, and that upgrades to the dam's engineering drove up costs.
The new design features several changes related to foundation stability, seismic protection, spillway safety and improved generating capacity. In the new design, the generating station and spillway have been rotated and are now at right angles to the dam, resembling an 'L.' According to BC Hydro engineer, Andrew Watson, the new design will minimize the depth of the excavation required under the generating station, which will reduce concerns over foundation stability.
The other major design change is to the dam's spillways. It includes the addition of an auxiliary spillway, which would provide capacity to discharge water if the spillway gates become inoperable. The spillway is also divided in half, which allows either section of the spillway to be repaired while retaining capacity on the other side.
New generating technology, which didn't exist when the dam was first designed in 1981, would increase the project's capacity by 22 per cent from 900 Megawatts up to 1,100 Megawatts and push the annual energy output up 11 per cent to 5,100 Gigawatt hours of energy per year.
Even with significant estimated cost increases, Conway explained that the $85 to $97 per megawatt cost of the project still falls below the expense of generating the same amount of energy using other clean production alternatives.
BC Hydro Socio-Economic Manager, Siobhan Jackson, explained that the filing of the Project Description Report gives regulators an idea of what the project is, what it will be used for and the effects it will have on local residents and wildlife. The recently submitted document will help regulators prepare for the upcoming pre-application process, where various stakeholders must be engaged to determine the scope of what will be considered in the environmental assessment.
Once the scope of inquiry is established, regulators will ask BC. Hydro to submit their research in the mandated areas for review, when they will make a decision on whether or not to certify the project.
Jackson said that BC Hydro's approach to assessing Site C's environmental impact is to look at how the project will change habitats and how those changes will affect species living in the area. By transforming the river into a lake habitat, Jackson said some species may benefit while others may face adversity. Where a species will be negatively affected, Jackson said BC Hydro will present mitigation strategies in their pitch to regulators.
Field work will continue this summer to add to research that will eventually be used in the project's environmental assessment.
Public consultations will be held throughout the pre-application stage for residents to provide input on what they believe should be considered as part of the environmental assessment. Another round of consultations will be held during the review stage where the public will be able to provide feedback on the application.
BC Hydro has not yet set a timeline for their environmental assessment stage.