ترجمه مختصره لملخص تقرير اللجنة الدولية للخزانات

Quote: A reservoir with Sufficient capacity can help alleviate floods downstream by storing some of all of the excess flow after heavy rains. However the very large dams which have the capacity to affect a flood on a major river are usually multipurpose projects, and financial and political pressures mean that keeping reservoir high to maximize electricity generation and water supply frequently takes precedence over keeping it low to make room for floodwaters> The risk to people living below dams is compounded by the ever present possibility of dam failure: a dam-burst flood is almost certain to be the most destructive which ever hits a river valley. High release from some major hydro dams due to their operating regime can both increase the damage caused during the normal flood season and caused unprecedented out-of- season inundation. According to a team of Argentina National Council for Scientific and Technical Studies, releases from Itaipu have caused "recurrent – sometimes catastrophic - flood". Salto Grande, a 1890 MW dam on the Uruguay River between Argentina and Uruguay, was supposed to reduce floods, but since it was completed flooding has increased, with among other consequences, the forced abandonment of some of the many inhabited islands in the lower Uruguay Basin. Numerous cases have been recorded of floods which have been made worse because dam operators held back water while the reservoir was filling, and then, when the rain kept coming, had hastily to open their floodgates to prevent their dam from being overtopped. India's Hirakud Dam was first justified in the name of flood control, yet extreme floods in the Mahanadi Delta between 1960 and 1980 were three times more frequent than before Hirakud was built. In September 1980, hundreds of people were killed after releases from Hirakud breached downstream embankment. Orissa's Chief Minister admitted that panic releases of water from Hirakud were responsible for much of the devastation but argued that if the water had not been discharged as quickly as possible, the dam could have failed. Many other deadly floods have been blamed on emergency releases from Indian dams. In 1978 nearly 65000 people in the Punjab were made homeless by floods exacerbated by forced discharges from Bhakra Dam. A member of the committee set up to investigate the floods admitted that Bharka had been close to being overtopped and stated that "If something had happened to the dam, then half of the Punjab would have been inundated". Eleven years later a similar flood occurred. This time an official from the agency in charge of managing Bharkra argued that if the water had not been discharged 'one of the worst catastrophes in the living memory' would have occurred. Half a million people living in Sacramento the State capital of California, narrowly escaped disaster in 1986 when releases from the Falsom Dam almost overtopped the levees protecting the city from the American River. Discharge data from Folsom showed that the dam operators had discharged their own operating procedures, allowing floodwaters to fill up the reservoir for 36 hours, and then, suddenly increasing discharges to beyond their designed maximum when the safety of the dam was threatened.