承前*1
Alan Yuhas and Julia Carrie Wong “Lake Oroville dam: emergency staff race to fix spillway before more rain strikes” https://www.theguardian.com/us-news/2017/feb/13/lake-oroville-dam-california-emergency-repairs-evacuation
カリフォルニア州のオロヴィル・ダムはまだ決壊していない。現在は破損した放水路（spillway）の応急的な補修に全力が注がれているようだ。
さて、放水路の脆弱性は既に12年前に環境団体によって指摘されていたようだ；
The weakness of the emergency spillway was foreseen 12 years ago by three environmental groups, according to the San Jose Mercury News. The Friends of the River, the Sierra Club and the South Yuba Citizens League filed a motion in October 2005 asking the government to require that the emergency spillway be reinforced with concrete*2.The groups warned that the earthen spillway was vulnerable to erosion and could cause massive flooding or even fail. The government rejected their appeal, insisting that the spillway was safe.
The dam is about 70 miles north of Sacramento, and just upstream and to the east of Oroville, a city of more than 16,260 people. At 230 meters high, the structure, built between 1962 and 1968, is the tallest dam in the US, topping the famed Hoover dam by more than 12 meters.
*1:http://d.hatena.ne.jp/sumita-m/20170213/1486990504
*2:Paul Rogers “Oroville Dam: Feds and state officials ignored warnings 12 years ago” http://www.mercurynews.com/2017/02/12/oroville-dam-feds-and-state-officials-ignored-warnings-12-years-ago/
