However infinite our water resources may seem, there is only a fixed amount. Water goes round -and-round the earth in a perpetual cycle, connecting all life on earth past, present and future. The water that makes all life possible today is the same water that kept dinosaurs alive. Only 3 percent of the earth’s water exists in reservoirs, outside of the ocean – in ice, the atmosphere, groundwater lakes, rivers and living things. Most of this freshwater is inaccessible because it is locked in polar ice or atmospheric vapor. That leaves less than 1 percent for humans and wildlife that depend on freshwater. This page is a great resource for teaching the water cycle.