The next time a big storm rolls through the region, you can test out Hydro One's Storm Centre. It's a live, realtime map showing large planned and unplanned outages in Ontario, including Ottawa and the surrounding area.
The site takes data from Hydro One and maps it onto a Bing interface. It was launched last year but I only came across the link in the past couple of weeks. I haven't been able to test it out during any large storms - can anyone vouch for its accuracy?
Related: Ottawa Services & Utilities Guide