How much water is required globally to sustain an expanding human population? What elements affect droughts, floods, waterborne illnesses, and water quality? What possible consequences might climate change have on the world's water supplies? This comprehensive introduction delves into the intricate realm of water resources, answering these and other related questions. The book's strength lies in its thorough treatment of the principles of hydrology, aquatic ecology, geomorphology, and hydrology. To keep students interested, it also includes examples from current events and online resources related to water resource issues. Chapters on the geomorphology, hydrology, chemistry, and biology of lakes, rivers, and wetlands follow a brief history of human use and impact on water in the book. The article discusses global problems related to water quality and quantity, major diseases, and possible solutions. Examples from the US and other countries are used to discuss water laws, water allocation, and the conflicts involved. This comprehensive overview of these important topics will be helpful to students in the environmental studies, life science, Earth science, and engineering departments.