Proposals for big pipelines and interprovincial power line projects will no longer have to prove they won't damage or destroy navigable waterways in Canada, under changes introduced by the government Thursday.

These big projects are exempt under the new navigation protection act proposed in the government's second omnibus budget bill. The new act would replace one of the country's oldest laws, the Navigable Waters Protection Act. It was established in 1882 and said that no one could block, alter or destroy any water deep enough to float a canoe without federal approval.

That act was amended in 2009 to leave the description of protected water largely up to the minister.

This new act focuses on providing federal protection only for Canada's busiest rivers, lakes and oceans. It's designed to do away with red tape created by the old act that said that even docks and culverts needed federal approval that often took years to get.

Federal Transport Minister Denis Lebel said the new act deals only with waterways used for navigation.

"We specially decide to show what is navigation — ditches or small, small rivers are not a place where we have navigation … this list of lakes and rivers has specific criteria for where we have navigation."

The act now provides a list of federally protected waters — three oceans, 97 lakes and 62 rivers. Any waterway not on the list that could be affected by a dam, pipeline, mine or bridge won't be protected by federal law. It will be up to provinces or municipalities to consider the projects.

Follows changes to environmental reviews

Green Party Leader Elizabeth says the proposed law is just continuing the destruction of environmental protections by the  first omnibus budget bill, C-38.

"In C-38, Stephen Harper cancelled and gutted environmental laws brought in by [former prime minister] Brian Mulroney," said May. "He's now moved on to destroy environmental law brought in by Sir John A. Macdonald."

It appears these changes could also alter the level of scrutiny applied to future big projects, such as Shell Canada's proposed Jackpine oilsands mine expansion north of Fort McMurray, Alta.

That project would reroute 21 kilometres of the Muskeg River. As that project is heading into public hearings this month, Transport Canada is still asking tough questions how the project would affect navigation and use of the river.

If this project were proposed under the navigation protection act in the future, Transport Canada would not be asking those questions, because the Muskeg River is not on the list of protected waterways, says Keith Stewart from Greenpeace.

"What's going to happen to projects like that? It's not a minor change, it will have major effects on the ecosystem," said Stewart.

"There are a lot of rivers not on the list that are used by Canadians and need to be protected," he said.

Transport Canada officials say big projects on waterways will still be assessed by the National Energy Board and under Canada's Environmental Protection Act. And they point out that transport officials would still provide "advice" as these assessments are underway.

But the NEB only looks at technical feasibility of building a project, not its environmental effects.

And Keith Stewart adds that scrutiny of projects under Canada's Environmental Assessment Act has been largely watered down.

"I think we are going to be seeing environmental protections just fall through the gaps created by the federal government."