Communities around the world are facing a variety of different problems related to the supply of water. Many of these are not new, having been faced by ancient civilizations, for example, the problem of irrigation in desert regions. A number of problems are becoming more urgent as a result of population growth and demand on aquifers. Improving understanding of groundwater behavior and remediation and advancing technology are helping to solve some of the most pressing problems; however, many groundwater issues continue to become more dire through time, especially in developing nations. Here, we discuss some of the most pressing problems. We stress that these problems are experienced globally, although we provide regional and local examples.