Small dams more dangerous to environment than large dams: study

Washington , Fri, 31 May 2013 ANI

Washington, May 31 (ANI): Small dams can pose a greater threat to ecosystems and natural landscapes than large dams, a new study has revealed.

Researchers from the Oregon State University in Corvallis who have conducted surveys of habitat loss and damage at several dam sites on the partially protected Nu River in China have found that the environmental harm from small dams was often greater, sometimes by several orders of magnitude than from large dams.

Researcher Kelly Kibler has found that 'small dams have hidden detrimental effects, particularly when effects accumulate' through multiple dam sites, and said that 'the perceived absence of negative effects from small hydropower is not always correct.'

Kibler and Tullos evaluated data from the field, hydrological models, and Environmental Impact Assessment reports about the small dams and concluded that impacts of the small dams exceeded those of large dams on nine of the 14 characteristics they studied.

Kibler explained that the small dams often divert the flow of the river to hydropower stations, leaving several kilometers of river bed dewatered.

Kibler noted that nearly one hundred small dams currently exist within Nujiang Prefecture alone.

While parts of the Nu River are designated as a World Heritage site and the Nature Conservancy and Conservation International have delineated stretches of this river and its tributaries as biodiversity hotspots, proposed hydropower projects are threatening these statuses, according to Kibler.

Stating that the lack of regulation along with a dearth of communication between small dam projects in China allows for the impacts to multiply and accumulate through several dam sites, Kibler said that there is a 'need for comprehensive planning of low-impact energy development'.

Many of the small dams investigated in the new study were supported by the Kyoto Protocol which is an agreement to reduce greenhouse gas emissions. (ANI)