Yes, there's plenty of water on the earth. But most of it is in oceans, or clouds. Less than 5% of the earth's water is potable at any one time. And modern, industrial-scale energy is often derived from a process that uses enormous amounts of water. Take coal...or nuclear...or natural gas. All boil lots of water to turn turbines to make electricity. You may hate dammed rivers, but at least that water is only drained of its kinetic energy and then passed on in pretty much its original state. Dams essentially tap into gravity as a source of energy. So far, not a single geologist has warned us of global gravity depletion caused by human activity. Whew.
Here's an interesting look at...ready for this...your water footprint. Sorta like the one you leave as you walk away from the swimming pool toward the cabana.