(1) The department, having determined that public water is available from the main stem of the Columbia River in Washington and that continued issuance of water right permits and certificates therefrom is in the public interest, does acknowledge and is concerned that, cumulatively, the projected future diversions from the main stem Columbia River in Washington state may, under certain flow conditions, have a detrimental effect on instream values.

(2) Also, it is in the public interest that the state's water resources be conserved and that the burden of water shortages in low water years should be shared by the various users to the greatest extent practicable.

(3) Notwithstanding the constraints on pro rata water-sharing under existing state water laws, the department shall, in projected low water years, utilize all reasonable measures of influence to achieve the goal of this section.

(4) During proof of appropriation of water under RCW 90.03.330 and before issuing a certificate of water right, the department shall assure that the quantities of water shown on the certificate accurately reflect the perfected usage consistent with up-to-date water conservation practices and water delivery system efficiencies.

(5) The department shall continue to seek effective methods to better achieve the goal of this section.