Dams: under scrutiny

Dams in the us are being dismantled to restore riverine ecosystems

Published: Sunday 15 August 1999

while environmentalists and the governments are on a warpath over dams in India, construction workers in the us began dismantling the 7.2-metre high, 85-metre-wide Edwards Dam on Maine's Kennebec River in the first week of July.

The dismantling was done in a move to restore the nation's rivers to good health and is expected to inspire the removal of other dams whose environment costs outweigh their benefits. The Edwards Dam generated only one-tenth of the annual energy used in Maine.

The removal will not only open the river for recreation but more importantly, nine species of Atlantic fish will have access to their traditional spawning grounds.

Outside pressure and independent scientific studies by non-governmental organisations like the American Rivers and Trout Unlimited helped in forcing the decision.

It is true that hydroelectric dams do not induce global warming or contribute to smog, but a recent study by American Rivers, cites the case of California's Butte Creek, where the population of Chinook salmons began to rise after small dams were breached last year. Other success stories will soon follow. The Federal Energy Regulatory Commission, which regulates the nation's 2,300 non-federal hydroelectric dams, has asked owners of the Condit Dam on Washington's White Salmon River to build fish ladders. Fish ladders help species like the salmon to move upstream for spawning.

However, the owners are considering removal of the dam instead. The owners of the Elwha and Glines Canyon Dams, which had virtually wiped out the salmon populations on Washington state's Elwha River, have agreed to sell their dams to the federal government.

The us administration is favourably disposed to dam removal, but its biggest test lies ahead. The administration is under a court order to devise a plan by the end of the river to save endangered salmons in Washington's Lowe Snake River. Many fish biologists say that the salmon will never recover unless Congress agrees to dismantle four large dams on the year. The fate of these dams is an emotional issue in the Pacific Northwest and several Senators are trying to block removal as an option.

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