While it looks like the planet's surface is covered mostly in water, the fact is there is very little water on this planet when you compare it to the size of the planet as a whole. The USGS created this image to give us a little perspective.
USGS states, "About 70 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water. But water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog. Still, all that water would fit into that "tiny" ball. The ball is actually much larger than it looks like on your computer monitor or printed page because we're talking about volume, a 3-dimensional shape, but trying to show it on a flat, 2-dimensional screen or piece of paper. That tiny water bubble has a diameter of about 860 miles, meaning the height (towards your vision) would be 860 miles high, too! That is a lot of water."
It may be a lot of water, but almost all of it is not usable for us. Over 96% is saline water in the oceans, and of the fresh water that's left, most of that is locked up in ice at the poles, is underground were we don't reach it, or is in the atmosphere.
Perhaps this will give us some perspective on how truly precious a resource water really is.