Authorizes a person entitled to divert or withdraw waters of the state to elect to forego water use or a portion thereof without the period of nonuse being included within the five-year period of nonuse constituting relinquishment, when the person provides prior written notice to the department of ecology regarding reduced use.

Requires the department of ecology to prepare a data gap analysis that evaluates existing groundwater and surface water information on water levels and water quality within each water resource inventory area of the state.