Of all the water on Earth, about two percent is stored underground in spaces between rocks. A fraction of a percent exists in the air as water vapor, clouds, or precipitation. Another fraction of a percent occurs in the bodies of plants and animals. So where is most of Earth’s water? It’s on the surface of the planet. In fact, water covers about 70 percent of Earth’s surface. Of water on Earth’s surface, 97 percent is salt water, mainly in the ocean. Only 3 percent is fresh water. Most of the fresh water is frozen in glaciers and polar ice caps. The remaining fresh water occurs in rivers, lakes, and other fresh water features.