As far as I know there is no winter kite ban at Melville.
However, no one really kites there in winter, nor should they.
The winds are on shore in the squalls, tricky, dangerous and crap to boot, especially for the less experienced.
The Council has been very generous to the hundreds of kiters that make use of the river in summer...which is fantastic. The Melville foreshore is the best place in summer, especially for those in the learning phase.
Ocean in winter for sure, and river in those magic easterlies.
Brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr.what an ugly day outside.......but will kite for sure
Surely you can kite when it's 10-45 knots and from three different directions in 5 minutes ? 
Mind you I had my *&^e whipped there last Friday whilst windsurfing 
