I could be wrong, but I think they used up a lot of the water and could not get more because power was down or could not get water intended for agricultural use diverted to the town.
I do not know the details either, but the stories talk about personnel not relasing the water? Sounds like someone turned off the spigot. Of course, as others have noted, the entire ocean was right there too.
agree..read there was some connection to water flow...pump stations??