Did Mars lose a lot of water or is it still there?

I keep reading about scientists locating frozen water with some of this water masses being large enough to fill the great lakes and they have also actually found liquid water on Mars not to mention the water at the poles.

I'm of the opinion that had Mars not lost a bit of its water there would be such a small landmass that a large human settlement couldn't live there.

via International Skeptics Forum http://ift.tt/1Qt3Wp5