There is the same volume of water as there has ever been, it is tied up in different material states. Some is ice, some is liquid and some is vapour.... the extra you are on about is in the sea, and will be evaporated into the sky due to the heat of the surface water then as the air cools and cannot hold the same volume of water vapour, it will come gushing out of the sky in great torrents... but it is the same water going around in the 'water cycle', it just isn't where we want it to be at the moment.