by Tanada » Wed 30 Dec 2015, 14:53:23
$this->bbcode_second_pass_quote('pstarr', 'T')anada, hydro is a mixed blessing. While it grants people comfort in the short term, it degrades local ecosystems, fisheries, agriculture and community. It is the first step in industrialization and consumerism and control by big government and big business. In the long run (decades, a century) the dam reservoir silts up.
$this->bbcode_second_pass_quote('', 'P')rofessor K. Mahmood of George Washington University in Washington, DC, "roughly estimated" for a 1987 World Bank study that around 50 cubic kilometres of sediment – nearly one per cent of global reservoir storage capacity – is trapped behind the world’s dams every year. In total, calculated Mahmood, by 1986 around 1,100 cubic kilometres of sediment had accumulated in the world’s reservoirs, consuming almost one–fifth of global storage capacity.
Long before then the streams above and the river below become degraded and fit only for industrial agriculture water supply. It is sad.
Yes onlooker we blew it and tragically much of that blowing occurred recently, only during my short time here at PO.com. 10 years ago the last great pointless suburban build-out was still underway in the US/Europe and China. We wasted valuable time and resources we will never see again on the greatest misallocation of resources in the history of the world, to quote Kunstler.
Propaganda. You would have to think that dredging and reservoir basal releases were impossible to accept that dams reservoirs silt up and become useless. Yup really, you have to use your brain and do something to prevent or remove the silt after it is deposited, gosh what a terrible high tech problem we face! Give me a break Pete, this is another one of those 'technical issues' created out of whole cloth by people who oppose hydroelectricity. Dredging technology has been around for all of recorded human history going back to the Ancient Sumerians and Egyptians. An Archimedes screw using well under 1 percent of the power produced or a silt diversion tunnel allowing a small quantity of base water to escape continuously prevents a dam from silting up. Regular dredging with a floating dredge like those used to keep shipping channels open also solves the silt issue if nobody though of it during construction.