“Just do an Internet search.” “It’s on the Internet” These phrases have quickly become a part of the vernacular. The quintessential book of data relating to water, The Water Encyclopedia: Hydrologic Data and Internet Resources, Third Edition arose from the premise that most of the information provided within this publication could be easily found on the Internet. As the editors and their team of contributors soon discovered, using the Internet for research can be problematic. Too much, too little, and questionable data sets can influence the caliber of your results. The new edition contains more than 1100 tables and 500 figures providing data related to weather, surface water, ground water, water use, water quality, waste water, pollution, and water resource management. The first two chapters are completely new and discuss data management and international data collection. The pollution chapter has grown to contain some 450 plus tables and figures. Wastewater, previously included within the pollution chapter, is presented as a new standalone chapter. Whether you are looking for a specific piece of information or exploring many topics, this edition is a portal to quality facts and data sets. Retaining the elements that made the previous editions bestsellers, the third edition elucidates the many changes within the environmental industry and in water-related issues during the last decade. Prepared by scientists and engineers, the book has been significantly expanded beyond the scope of the second edition. Reflecting changes not only in information but also technology, whenever possible, the text includes an Internet address that guides you to the appropriate source.