What are the costs of hydroelectric energy?
Hydroelectric power has been touted as the 'environmentally
clean, renewable source of power.' This is subject to debate, as
hydroelectric dams use turbines to generate electricity, and these
turbines are spun by shafts which have blades on them. Fish which
get caught in the high-pressure streams of water directed at the
turbine blades usually do not survive the encounter with the
blades. Also, the impoundments, or lakes, behind hydroelectric dams
slow the speed of the river so much that many young fish do not
survive the long swim to the ocean, where food is plentiful in
comparison to rivers. Of course, dams present a complete barrior to
upstream migration, unless fish ladders are in place, and even fish
ladders are not 100 percent effective, as many fish are unable to
locate the ladders. Salmon populations upstream of Grand Coulee
Dam, which does not have fish ladders, disappeared, except for the
freshwater varieties.