Visualizing Water – Slide 6

Just as we can look at the global water cycle in this way, we can look at the annual cycle of water in a single river basin, such as the Colorado River Basin in the American West.
Every year, 65 Billion Cubic Meters (BCM) of rain and snow falls in the Colorado River Basin. In the absence of human use, nearly two-thirds of that water is absorbed by soil and taken up by plants as green water before being evaporated or transpired up into the atmosphere. Another 31% finds its way into rivers and lakes as surface water, and another 6% finds its way into underground rivers and aquifers as groundwater. Just as with the global water cycle, that blue water would have historically found its way into the oceans and evaporated back up into the atmosphere.