The province has asked the Public Utilities Board to look at the Keeyask and Conawapa (kahn-ah-WHA'-pah) generating stations and transmission facilities.
Energy Minister Dave Chomiak (CHOH'-mee-ack) says the review, which is standard for new mega-projects, will assess demand for new power sources and consider alternatives such as natural gas.
Chomiak and Hydro officials have already said new hydro projects are needed to feed growing energy demand within the province and in the United States.
But critics point to reduced export sales to the U.S., primarily due to the recession.
Hydro is also competing for exports at a time when natural gas prices have dropped.
The utilities board warned last year that low prices could force Manitoba consumers to subsidize exports and cause domestic prices to jump by 140 per cent over the next 20 years.
Hydro CEO Scott Thomson told a business audience in September that world prices will rise again.
Even if exports are not counted, Thomson said in-province usage will grow by 1.6 per cent annually, eating up much of the power being generated by the Wuskwatim dam that opened earlier this year.
The province also announced Friday that another review by the Clean Environment Commission is being prepared to assess the impact the Keeyask generating station would have.