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| Threat to navigation structures on the Snake River (USA) | |
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Environmental protection interests in the States of Washington, Oregon and Idaho are currently engaged in a vigorous campaign for removal of four hydropower and navigation dams on the River Snake, tributary of the Columbia. This extraordinary proposal is one of the measures designed to save from possible extintion five species of salmon and trout, especially the chinook and the hammerhead trout. When Lewis and Clark discovered the Snake in 1805, they estimated that between 5 and 8 million adult migrators reached the Snake every year from the Pacific. Today there are barely 5000, all told. Development of the Columbia-Snake waterway for hydroelectric power and navigation was completed in 1975 (a few years before the Rhone in France), and allows push-tows up to 152 metres long and 23 metres wide to trade to the inland port of Lewiston, Idaho, 750 km from the Pacific and 222 metres above sea level. It includes the deepest lock in the world at John Day dam (maximum fall of 34.40 m). When the structures were built, the US Army Corps of Engineers took into account the needs of the migrators by building fish passes for adults returning upstream and barge or truck transport for the young smolts heading downstream. However, the migrators have been reluctant to adopt these alternatives to swimming freely with (or against) the flow. Freight movements through the lowest lock on the Snake (Ice Harbor) are 4 million tons per year, three quarters of which is grain: wheat and barley exported through the port of Portland. Container traffic (10 000 boxes per year) concerns lentils, peas and pulp for the paper industry. The outcome of this conflict of interests could have major repercussions for waterways as transport arteries, the interests of which are evidently less well defended than those of biodiversity and preservation of ecologicial balances. Advocates of what is termed "partial dam removal" invoke the treaties signed in the 19th century with the Indians, guaranteeing them salmon fishing rights in the rgeion. Compensation which could be due to them under this heading is estimated at between $6 and 12 billion. Another estimation of lost fisheries production reaches the sum of $6.5 billion (in net present value). Compared to these staggering figures, the costs resulting from elimination of navigation on the Snake appear to be "reasonable", at least that is what the environmentalists would have us believe: a dollar per month on the average household's electricity bill for replacement energy, between $60 and $90 million per year (amortized costs) for dam removal, and $47 milllion per year for transportation above current costs. This does not take into account the one-time investment of $315 million to improve railway and road infrastructure to handle the traffic currently barged on the Snake. With economic stakes of this importance, it is hard to imagine that solutions cannot be found to improve efficiency of the fish passes. |
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Map
of the Columbia-Snake |
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