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. The 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.