17 In March 1997, in rural Hebei and Henan Provinces in China, several hundred farmers from neighboring villages clashed over access to water resources to irrigate their crops, leading to dozens of injuries. The rivers that used to supply all their needs were drying up. Two years later, violent conflicts over water escalated in the same region. Hundreds more villagers were injured and water diversion facilities destroyed. In 1999, some 700 soldiers were sent to quell fighting that claimed six lives and injured 60 others in clashes that erupted between two Yemeni villages fighting over a local spring. In 2001, civil unrest in Pakistan over severe water shortages led to protests, riots, and bombings, killing one and injuring dozens. In 2004, a similar dispute in a bordering region of India led to four deaths and more than 30 injuries. Between 2004 and 2006, at least 250 people were killed and many more injured in Somalia and Ethiopia in fighting over water wells and pastoral lands. Villagers there call it the War of the Well and tell stories of “well warlords, well widows, and well warriors.” Across the globe, these sorts of public protests, disputes, and violence over water are increasingly common as problems of contamination, shortages, and allocation grow. In rural villages and expanding cities around the world, water is an increasingly scarce and contaminated resource. As populations and water demands continue to expand, the heightened risk of violent conflicts over water use and contamination suggest new calls for fundamental changes in the way we manage and use this precious resource. The world of water is changing— not just how much water is available, or who controls it, but the whole way we think about and manage this precious commodity. The assumptions we made in the last century about the availability and use of water no longer seem to apply. And for water managers, planners, hydrologists, engineers, economists, policy makers, and concerned citizens, the time has come for new thinking and new solutions. Over the past several centuries, societies have developed different technologies, practices, and institutions for supplying safe and reliable freshwater, dealing with extreme events, as well as collecting, treating, and disposing of wastewater. These tools brought enormous benefits to humankind. But they have also failed to solve some of our most difficult water problems, and in key ways they are unsuited to our new Peter H. Gleick is co-founder and president of the Pacific Institute in Oakland, California, a MacArthur fellow, and member of the U.S. National Academy of Sciences. He is the author of seven books, including the biennial report, The World’s Water (Island Press).