In April 1850, the California Legislature adopted the English Common Law as the basic legal framework for California. Gold, not so much water, was on the minds of many in early California, and they did not ponder what this action meant in relation to water. English Common Law recognizes riparian rights to water as the main legal doctrine governing the use of water, and so it became California law.
Riparian rights are rights to divert, use and enjoy waters from a stream that abuts your landed property, your real estate. If you own land that has a stream next to or running through it, you probably have riparian rights to divert water from the stream and use it to grow crops or for other purposes specific to your property.
For most riparian right holders in California, you cannot lose your water rights merely by your own non-use of the resource, unless someone obtains a “prescriptive right” by diverting for at least five years without a challenge from you.
Riparian rights are held in common by all the land owners along a stream or river here in California. They have “correlative rights” with respect to each other; that is, they own a right to use a percentage of the flow of the stream every year, a percentage which doesn’t change. In dry years, however, they must take less from the stream, according to the riparian doctrine.
Besides riparian rights, the other major doctrine of water rights in California is known as prior appropriation or “appropriative rights.” In contrast to the origins of riparian rights, the doctrine of prior appropriation originated as possessory rights among gold miners working claims on federal land (also referred to as “the public domain”).
To minimize disputes among miners, both mining claims and water diversion claims were subject to right by priority of having put both the land and the water to use mining gold.
Simply put: whomever got the claim first got to work it first, and whomever diverted the water to work the claim first (for sluicing and sorting the gravels and separating out gold) had priority over claimants who came later.
Hence, the appropriative right is summed up by the phrase: First in time, first in right.
Appropriative rights have another important component to them: the obligation by the appropriator to show due diligence in working their claim and using the water on it. They could not simply lodge a claim and then sit on it.
Beginning in 1914, the state of California centralized the granting of appropriative right permits initially with the California Water Commission. Later in the 1960s, permitting responsibility shifted to the State Water Resources Control Board, where it resides today. They may regulate all water rights that are initiated after 1914, but prior to 1914, the Board is only allowed to investigate problems with older rights.
Prescriptive rights have a long tradition in American property law. Many trail corridors and public access to beaches have been obtained through legal prescription—through continual and well-documented usage over the rights of private property holders.
As a water right holder (either riparian or appropriative) you could lose your water rights through “prescription.” The situation starts where someone using water you might have used. If they use it for five years or more without you challenging their usage, then they have probably acquired their rights to water through prescription.
Among the rights you may acquire when you purchase a piece of land in California is a right to groundwater. Groundwater rights are called “overlying rights,” and like riparian rights they attach to your land.
Also like riparian rights they are “correlative”; you own a percentage of the percolating water that exists under your land in common with the other landowners in your neighborhood.
Except in areas where water rights in a groundwater basin were settled (or “adjudicated”), groundwater pumping is at present unregulated in California.