For the purposes of this chapter the following definitions shall apply:

(1) "Aquifer" means a geologic formation, group of formations or part of a formation capable of yielding a significant amount of groundwater to wells or springs.

(2) "Department" means the Washington state department of ecology.

(3) "Groundwater" means all waters that exist beneath the land surface or beneath the bed of any stream, lake or reservoir, or other body of surface water, whatever may be the geological formation or structure in which such water stands or flows, percolates or otherwise moves.

(4) "Groundwater advisory committee" means a committee appointed by the department to assist in the development of a groundwater management program.

(5) "Groundwater area or subarea" means a geographic area designated pursuant to RCW 90.44.130.

(6) "Groundwater management area" means a specific geographic area or subarea designated pursuant to this chapter for which a groundwater management program is required.

(7) "Groundwater management program" means a comprehensive program designed to protect groundwater quality, to assure groundwater quantity and to provide for efficient management of water resources while recognizing existing groundwater rights and meeting future needs consistent with local and state objectives, policies and authorities within a designated groundwater management area or subarea and developed pursuant to this chapter.

(8) "Groundwater management zone" means any depth or stratigraphic zone separately designated by the department in cooperation with local government for groundwater management purposes within a groundwater management area. Groundwater management zones may consist of a specific geologic formation or formations or other reasonable bounds determined by the department consistent with the purposes of this chapter.

(9) "Groundwater right" means an authorization to use groundwater established pursuant to chapter 90.44 RCW, state common or statutory law existing prior to the enactment of chapter 90.44 RCW, or federal law.

(10) "Groundwater user group" means an established association of holders of groundwater rights located within a proposed or designated groundwater management area.

(11) "Lead agency" means the agency appointed by the department to coordinate and undertake the activities necessary for the development of a groundwater management program. Either the department or an agency of local government may be the lead agency.

(12) "Local government" means any county, city, town, or any other entity having its own incorporated government for local affairs including, but not limited to, a metropolitan municipal corporation, public utility district, water district, irrigation district, and/or sewer district.

(13) "Local government legislative authority" means the city or town council, board of county commissioners, special district commission, or that body assigned such duties by a city, county or district charter as enacting ordinances, passing resolutions, and appropriating funds for expenditure.

(14) "Probable groundwater management area" means a specific geographic area identified by the department, in cooperation with other state agencies, local government and groundwater user groups, as a candidate area for designation as a groundwater management area pursuant to this chapter.