Mind-boggling lunacy, or is it just too late at night?

Here's something I am struggling to understand: the current plans for a Desalination plant in Sydney. My problems are as follows:

1. In an era of concern over greenhouse gas emissions and climate change, why did the government choose to build a very expensive and very high greenhouse gas emitter?

2. Why is Sydney Water leaving a $2 billion installation cost out of its expense calculations?

3. Why are they going to run it even when dams are 70-80% full, when as the article above mentions 58% will do the city for 6 years?

4. Why build it when most Sydneysiders don't want it anyway???

I can't help thinking that Bob Carr did some dodgy dealings before he did a runner, and locked the state into an expensive contract of some sort. But then, I am writing late at night, so I might just be a little delirious. If you have any insight on this matter, please enlighten me.