As used in this chapter, unless the context requires otherwise: “Beneficial use” means both instream and offstream uses. Instream beneficial uses include but are not limited to protection of fish and wildlife habitat, maintenance of waste assimilation, recreation, navigation, and cultural and aesthetic values. Offstream beneficial uses include but are not limited to domestic (including public water supply), agricultural, electric power generation, commercial, and industrial uses. Domestic and other existing beneficial uses shall be considered the highest priority beneficial uses. “Board” means the State Water Control Board. However, when used outside the context of the promulgation of regulations, including regulations to establish general permits, pursuant to this chapter, “Board” means the Department of Environmental Quality. “Nonconsumptive use” means the use of water withdrawn from a stream in such a manner that it is returned to the stream without substantial diminution in quantity at or near the point from which it was taken and would not result in or exacerbate low flow conditions. “Surface water withdrawal permit” means a document issued by the Board evidencing the right to withdraw surface water. “Surface water management area” means a geographically defined surface water area in which the Board has deemed the levels or supply of surface water to be potentially adverse to public welfare, health and safety. “Surface water” means any water in the Commonwealth, except ground water, as defined in § 62.1-255.