August 23, 2009
However, concerns have begun to be raised by environmentalists: it’s not so much one dam that concerns them but the cumulative impact of hundreds of dams. This isn’t hyperbole: 500 sites for these small dams have been located in Washington State.
Even small hydroelectric dams could have big impact on fish populations, as well as habitat for other wildlife in the area, especially considering these dams are often placed deep in backcountry and on untouched streams.
In addition, critics contend that the dams are simply not providing enough power to outweigh disadvantages. According to the Wall Street Journal, the U.S. Hydropower Resource Assessment report for Washington state in 1997 found that improving efficiency on current hydroelectric dams as well as adding hydropower capabilities to dams that lack it would provide over three times the amount of energy provided by building small dams on all of the state’s available sites. One of the problems with such dams is that if water dips below a certain level, the dam stops producing altogether, much like wind turbines when the breeze isn’t blowing.
Still, many small hydroelectric dams are moving forward. They are popular in British Columbia where 60 such dams have received licensure in the past decade. Colorado is looking at building ten or so of them where existing infrastructure is in place, and the dams have become popular proposals in other states such as Washington, Oregon, and Montana. All told, there has been a 20 percent rise in proposals in the last two years in the United States.
Such dams are also popular around the world. As of 2005, China was the world’s largest builder of small hydroelectric dams followed by Japan, the United States, Italy, and Brazil.
New Yangtze River dam could doom more endangered species
(06/22/2009) Eight Chinese environmentalists and scientists have composed a letter warning that a new dam under consideration for the Yangtze River could lead to the extinction of several endangered species. The letter contends that Xiaonanhia Dam, which would be 30 kilometers upstream from the city of Chongqing, will negatively impact the river’s only fish reserve. Spanning 400 kilometers in the upper Yangtze, the reserve is home to 180 fish species, including the Endangered Chinese sturgeon, and the Critically Endangered Chinese paddlefish, as well as the finless porpoise.
Dams in Laos threaten Asia's largest waterfall, critically endangered river dolphin
(03/16/2009) Eleven proposed hydroelectric projects on the Mekong River in Southeast Asia threaten migratory fish stocks, regional food security, and the livelihoods of millions of people, warns a new campaign launched by environmental groups.
Brazil OKs $4 billion dam in the Amazon rainforest
(11/13/2008) Brazil has given final go-ahead on a controversial dam on the Madeira river in the Amazon rainforest provided environmental conditions are met, reports the Associated Press.