VANCOUVER -- The joint review panel weighing the future of the massive Site C dam in northern British Columbia says the benefits of the multibillion hydroelectric project are clear.

But in a report that gives no clear yes or no answer, the panel says the Crown-owned utility has not demonstrated the need for the dam on the timetable it set forth.

"B.C. will need new energy and new capacity at some point," the report said. "Site C would be the least expensive of the alternatives."

The panel cited significant adverse effects to fish and wildlife and said construction of the $8-billion dam would have "the usual" health and social risks common to boom towns.

Among the recommendations, the panel said the project should be referred to the provincial BC Utilities Commission for a detailed examination.

The provincial government previously exempted the project from the commission, which rejected a previous incarnation of the dam.

But there are few alternatives to provide the kind of long-term energy source the dam would provide, the panel found. The report contains 50 recommendations for the project, should it be approved.

"We're pleased that the panel has confirmed that there will be a long-term need for the new energy and capacity that the Site C project would provide," said Dave Conway, spokesman for BC Hydro.

"I think it's a signal that, generally, the panel has agreed with the work that we have done to date, our suggested mitigation plans and the investigation work, and have added to that with their recommendations."

The report was delivered earlier this week to the federal environment minister and the head of the B.C. Environmental Assessment Office. It was released to the public on Thursday.

The provincial and federal governments have six months to make a final decision on whether the dam proposed by B.C.'s Crown-owned utility company can proceed.

The dam proposed by BC Hydro would be the third on the Peace River in northeastern B.C.

It would create a 9,330-hectare reservoir along 83 kilometres of the river, flooding about 5,550 hectares of land.

The dam is estimated to generate up to 1,100 megawatts of capacity -- or enough to power the equivalent of 450,000 homes a year.

BC Hydro said it is a clean, cost-effective source of much-needed electricity for the province, but opponents say it will cause irreparable harm to an important agricultural region.

Provincial Energy Minister Bill Bennett noted that among its recommendations, the panel suggested the federal and provincial governments do more First Nations consultations.

He said both governments must decide whether the benefits of the project outweigh the impacts cited in the report.

Construction would take eight to 10 years. If all goes through, ground could break in January 2015, Bennett said.