There is something like 10 more days of rain expected in the already flooded watershed above the dam so it will be full and then some for weeks as all that water drains off, meanwhile they have the emergency sluceways wide open to (try to) keep the dam from overflowing/collapsing. No way to drain it, more water coming for 2-3 weeks, they are stuck with what they have to ride this out. A dam failure will cause far more damage than the devastation of a 200Megaton Hydrogen bomb. 400M people could be effected downstream. The damage would be like the tsunami that hit Japan in 2011 but impacts many many more people.