Washington’s water law includes a principle that a water right is perfected, defined, and maintained through beneficial use. The expression “use it or lose it” is sometimes applied to describe this western water law principle. Put simply, a water right may be wholly or partially lost through extended periods of non-use. The return of unused water to the state is called relinquishment. The purpose of relinquishment is to ensure that Washington’s limited water sources are put to maximum beneficial use for all of Washington’s citizens. To keep it simple, 5 or more successive years of non-use causes relinquishment unless you have good cause for said non-use. There are several categories described in RCW 90.14.140 that forgive the non-use.