Addresses the state supreme court decision in Whatcom County v. Western Washington Growth Management Hearings Board solely by providing immediate and temporary relief to landowners affected by the decision by ensuring that a water well report for a groundwater withdrawal exempt from permitting and not prohibited by an applicable water resources management rule adopted by the department of ecology may serve, until July 1, 2019, as evidence of an adequate water supply for a building necessitating potable water.

Allows cities and counties, until July 1, 2019, to rely on water resource management rules adopted by the department of ecology in providing for the protection of surface water and groundwater except in certain water resource inventory areas.

Creates a joint legislative task force on water supply to review the treatment of surface water and groundwater withdrawals.

Provides a June 30, 2019, expiration date for the task force.