 In 1998 a flood in the same area caused billions of dollars in damage ; 2 @,@ 039 km2 ( 787 sq mi ) of farm land were flooded . The flood affected more than 2 @.@ 3 million people , killing 1 @,@ 526 . In early August 2009 , the largest flood in five years passed through the dam site . The dam limited the water flow to less than 40 @,@ 000 cubic metres ( 52 @,@ 000 cu yd ) per second , raising the upstream water level from 145 @.@ 13 metres on August 1 , 2009 , to 152 @.@ 88 on August 8 , 2009 . 4 @.@ 27 cubic kilometres of flood water were captured and the river flow was cut by as much as 15 @,@ 000 cubic metres per second . 
