http://alberta.ca/budget/
Long story short ... it's about really, really poor prospects for the oilsands going forward, added to a very uncertain fiscal situation:
http://www.cbc.ca/news/canada/calgary/alberta-budget-debt-wi...
For what it's worth, yes, this is what we get for being hewers of wood, drawers of water, etc. Traders don't call CAD a commodity currency for nothing.
Edit: wrong link!