I think this is old news. It was in the papers last May and was reported here. Teck used the dam as a guaranteed source of cheap power for their Trail Ops for years and along with the sale got a fixed (as in low) price for quite a long time without having to put out a huge amount of money for upgrades to the dam. The date on the below link is from last May.

http://vancouversun.com/business/local-business/teck-resources-to-sell-stake-in-waneta-dam-near-trail-for-1-2-billion