The Science of H₂O
Escuela de Ciencias del Agua (Español)
The Water Science School in Spanish
Earth's Water - the Basics
Discover the how, what, where, and why of water
The Water Cycle
The most comprehensive explanation of Earth's water-cycle components, with diagrams in 60+ languages
What Makes Water Water?
Sure, water is wet...but it is a whole lot more. Learn about water's properties.
Welcome to the Science Topics page of the USGS Water Science School, where you can explore the many aspects of water. All of our science information is available by browsing the Themes below.