This is not a river: California Aqueduct near Byron.

Photo by Tim Stroshane

"Paper water" is the idea that government has promised more in rights to water than there is water that flows in Nature's rivers and streams in California. There is far more water "on paper" than there is in California's water ways. 

For every acre-foot of real water in the Central Valley watershed, 8.4 acre-feet of water on paper has been promised by the state where only 1 acre-foot may actually be diverted, according to the State Water Resources Control Board.

The historical agencies of California responsible for post-1914 appropriative water rights vastly overcommitted water from the Bay-Delta’s Central Valley watershed streams. In September 2008, the State Water Resources Control Board reported to the Delta Vision Blue Ribbon Task Force (scroll to bottom of page for "Water Rights Within the Bay/Delta Watershed") that while the Central Valley watershed of California has an average annual runoff of 29 million acre-feet, the face value of water rights granted by the state to appropriative water right holders amounted to 245 million acre-feet.

Paper water can take two basic forms when:

• Water rights issued for a watershed exceed the water actually available.
• Water service contract allocations within a project prove to be consistently unreliable.

The existence of paper water arouses conflict with holders of riparian rights, such as occurs between the State Water Project and the Central Valley Project with Delta riparian farmers.