What are priority dates?
Oregon water law operates on a “first in time, first in right” basis. This means those water users who have the oldest “priority dates” have preferential access to water in situations where there isn’t enough to go around. In the Klamath Basin, non-tribal water rights claims in the Adjudication all pre-date 1909, and some are as early as the 1860’s. The Klamath Tribes’ instream Adjudication claims have a priority date of “time immemorial”, which is senior to all other priority dates. A “late date” or “junior” water right is one that is later than the right of someone else. For example, all water rights with dates after 1905 are “junior” to the Klamath Irrigation Project. A “senior” water right holder can place a “call” on the water system that serves his water right. This may require “junior” water rights holders on the same system to stop using water until the senior water right is satisfied. “Time immemorial” means the courts have found that Klamath instream flow rights (for fish) ha