Rumble in Outland:

Zangarmarsh

The delicate ecology of Zangarmarsh has been thrown out of balance. Unnatural phenomena are corrupting and destroying the marsh's native flora and fauna. This disturbance has been traced to the foreboding Coilfang Reservoir. It is rumored that the leader of this mysterious edifice is none other than the infamous Lady Vashj. Their exact reason for doing this is somewhat unclear; one theory is that they're attempting to control Outland's sparse amount of water - another is that they're planning to make a new Well of Eternity.