"Appropriation" means the process of legally acquiring the right to use specific amounts of water for beneficial uses, consistent with the ground and surface water codes and other applicable water resource statutes.

"Consumptive use" means use of water that diminishes the volume or quality of the water source.

"Ecology" or "department" means the Washington state department of ecology.

"Hydraulically connected" means saturated conditions exist that allow water to move between surface water and groundwater, or between groundwater sources.

"Instream flow" means a stream flow level set in rule to protect and preserve fish, wildlife, scenic, aesthetic, recreational, water quality, and other environmental values; navigational values; and stock watering requirements. The term "instream flow" means "base flow" under chapter 90.54 RCW, "minimum flow" under chapters 90.03 and 90.22 RCW, and "minimum instream flow" under chapter 90.82 RCW.

"Mitigate" or "mitigated" means actions taken to offset adverse impacts by new water appropriations on senior water rights, including the instream flow levels set in WAC 173-557-050.

"Municipal water supplier" means an entity that supplies water for municipal water supply purposes as defined in RCW 90.03.015.

"Permit-exempt groundwater withdrawal" means a groundwater withdrawal exempted from ecology water right permitting requirements under RCW 90.44.050, but which is otherwise subject to the groundwater code and other applicable regulations.

"Stream management unit" means a stream segment, reach, or tributary used to describe the area to which a particular use, action, or instream flow level applies. Each of these units contains a control station. A map of the control stations is included in WAC 173-557-110.

"SVRP aquifer" means the Spokane Valley Rathdrum Prairie aquifer.

"U.S. Geologic Survey Scientific Investigations Report 2007-5041" refers to the hydrogeologic framework and groundwater budget of the Spokane Valley Rathdrum Prairie aquifer, Spokane County, Washington, and Bonner and Kootenai counties, Idaho; U.S. Geologic Survey Scientific Investigations Report 2007-5041 by Kahle, S.C., and Bartolino, J.R., 2007.

"Water resource inventory area (WRIA)" means one of the sixty-two areas designated by the state of Washington through chapter 173-500 WAC to delineate area boundaries within the state for water management purposes.

"Withdrawal" means the extraction and beneficial use of groundwater, or the diversion and beneficial use of surface water.