It's really a tough situation for them. In order to bleed the water they have to construct runoff channels so that the flowing water does not erode
the barrier itself. Not an easy task, and there are over 35 of these artificial dams to deal with. I'm still trying to imagine what 4.5 billion
cubic feet of water (behind the largest of them) would look like.
I remember a
massive landslide blocking a river near where I grew up, (it was the
costliest landlside in US history and placed an entire town under a lake) and what a massive undertaking it was to remedy.
Considering that they have over 40 of these to worry about, they are in for some serious problems, and this story does not even take into account the
existing dams which were damaged. It's just staggering what an earthquake can do to a country.