What is the Earth's "water cycle?"

Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories . That data is revised every 5 years. As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

Earth is estimated to hold about 1,386,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows: Oceans (saline) 1,338,000,000 cubic kilometers Ice caps and glaciers (fresh) 24,064,000 cubic kilometers Groundwater (fresh and saline) 23,400,000 cubic kilometers Streams, lakes, swamps (fresh) 104,590 cubic kilometers Lakes (saline) 85,400 cubic...

Information on the flow of rivers is a vital national asset that safeguards lives, protects property, and ensures adequate water supplies for the future. The USGS is the federal agency responsible for operating a network of about 7,000 streamgages nationwide. Data from this network are used by water managers, emergency responders, utilities, environmental agencies, universities, consulting firms...

Groundwater is water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table. Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows...