Big Hydro: Environmental Impacts
08/18/10 7:50AM By John Dillon  Download MP3
(Host) And now, Big Hydro, our series on Vermont's plans to buy a quarter of its electricity from Hydro-Quebec.
Large hydroelectric dams are seen as one of the most environmentally friendly energy sources in a world struggling with climate change.
But damming rivers and redirecting their flow isn't benign. Fish habitat is harmed. Mercury is released into the environment. And the projects themselves can even release greenhouse gases.
In today's report, VPR's John Dillon takes us to the source and explores environmental impacts of northern Quebec power dams.
(Dillon) Hydro-Quebec has re-engineered the landscape and harnessed big rivers to send electricity south. The latest project is east of James Bay, near the Cree village of Nemaska.
(Jimikin) "So there's three river basins affected by all this, you have the Rupert, the Lemare and the Nemaska River. And all the water eventually goes into the existing EM reservoir."
(Dillon) Lawrence Jimikin is a Cree liaison with Hydro-Quebec. He's standing near steel gates several stories high at one end of a diversion dam that stretches a quarter mile across the Rupert River. Jimikin lights a cigarette and explains how the river's water is channeled 200 miles north to power a series of generating stations.
(Dillon) "So what we're looking at, those two big hooks come down, just grab the metal gate and lower it up and down?"
(Jimikin) "Actually, they're on steel cables. The doors are raised up and down by steel cables. And it's electronic. They're controlled by Montreal."
(Dillon) By mid-summer, Hydro-Quebec cuts the flow by 75 percent. That kind of fluctuation has a profound effect on river ecosystems, says Mark Bain, associate professor of systems ecology at Cornell University. Bain says the changes are bad for fish that require cool, running water to live and spawn.
(Bain) "They have a big impact because they flood a lot of land, and divert rivers into one basin, and they de-water rivers."
(Dillon) The damage locally can be profound and there are concerns worldwide about the impact of large hydro dams on scarce water supplies. But Bain says the Quebec projects benefit the global environment because they produce electricity without contributing to climate change.
(Bain) "Hydro is one source, replacing those dirtier sources."
(Dillon) And, yet, it's not quite that simple. There are some greenhouse gases produced by the hydro projects. Flooded land releases carbon dioxide and methane as the vegetation decomposes underwater.
But research shows that the emissions decrease in a few years. Yves Prairie is a scientist at the University of Quebec in Montreal who is leading a multi-year study of Hydro-Quebec's projects.
(Prairie) "So basically you have this pulse and then it's going to stabilize. It's going to take a little bit of time to stabilize, but it's going to stabilize at a level that is much lower than what is originally seen right after flooding."
(Dillon) Other research has focused on the mercury that leaches from the flooded land. Mercury is particularly toxic for babies and pregnant women, and it's been found in the fish the Cree eat. H-Q spokesman Claude Demers says mercury levels have declined in older reservoirs.
(Demers) "When we are flooding land in Quebec, in Sweden in Russia, everywhere you increase for a period of 20 to 30 years the mercury. But in La Grande, which is 30 years old, the fish is the same mercury level than all the natural water bodies around."
(Dillon) Beyond the science is something less tangible but still very real for people who knew the vast territory of northern Quebec before the utility began flooding it for electricity generation.
(Dillon) More than a thousand miles south of James Bay, in a cabin on Vermont's Lake Dunmore, Seth Gibson unrolls maps of northern Quebec.
For him and others who love pristine places, the vast hydro projects have permanently altered a landscape that was unchanged for centuries. Gibson recalls big, wild rivers he once knew.
(Gibson) "There's your Fort Rupert. And the next one up above that would be the Nemaska. This all shows a nice flow where it doesn't happen anymore."
(Dillon) For decades, Gibson led wilderness canoe trips for Camp Keewaydin in Salisbury. He hired Cree guides and spent up to seven weeks in the backcountry.
(Gibson) "First trip up there was in 1967, and those days you couldn't drive to Mistassini Post, you had to drive to the river head and put your canoe in the water and then paddle.
(Dillon) Gibson recalls the changes he's seen since Hydro-Quebec began its 17,000 megawatt James Bay project. Roads were built and nine rivers dammed or diverted. On a recent trip north, Gibson saw what's left of the Eastmain River, once a favorite with canoeists but now blocked by a dam.
(Gibson) "I've got a picture of it when we portaged around it, and then a picture of it when it's empty now. And there's nothing to see."
(Dillon) With Gibson is Hans Carlson, a historian and writer who first fell in love with the Cree country of northern Quebec on a canoe trip in 1982. Carlson has since become an advocate for the natives and their sub-arctic environment.
Carlson says development such as mines and clear-cutting often follows the hydro projects. He says Vermonters need to be aware that when we buy electricity from the north we export the impacts of our energy demand.
(Carlson) "There are people on the other end of the electric wires. The electricity is being generated somewhere else, and when we use electricity when we sign contracts for electricity there are going to long-term consequences and not just long term prices. People ought to take those into consideration."
(Dillon) Hydro-Quebec broke ground last year on its newest power project, a 1,500 megawatt facility on the Romaine River, an Atlantic salmon stream that flows into the Gulf of St. Lawrence. Carlson says the issues there are familiar - a pristine river being dammed to satisfy energy needs in the south.
For VPR News, I'm John Dillon.
(Host) Tomorrow in "Big Hydro," VPR looks at the cultural impacts of the hydro-power development.