Every March 22, the world observes World Water Day. The United Nations created this day in 1993 to draw attention to one of the most important resources on the planet. Water covers about 71 percent of Earth's surface, but most of it is saltwater in the oceans. Only about 3 percent is freshwater, and most of that is locked in ice caps and glaciers. Less than 1 percent of all water on Earth is available for people to drink. This tiny amount must serve over 8 billion people. About 2.2 billion people worldwide lack access to safely managed drinking water. In many parts of Africa and Asia, families walk miles every day to collect water from rivers or wells that may contain harmful bacteria. The water cycle constantly recycles the same water. When the sun heats water in oceans and lakes, it evaporates into the air. The vapor rises, cools, and forms clouds. When clouds become heavy, water falls as rain or snow. This process is called precipitation. The same water that dinosaurs drank millions of years ago is the water we drink today.