(1) Through well data collected since 1958 and refraction seismic surveys conducted in 1970 and 1971, the department of ecology has identified a semiclosed groundwater basin in the area of Duck Lake in Okanogan County, Washington.

(2) The principal aquifer in this area consists of glacial and fluvial sands and gravels that lie unconformably over metamorphic and igneous bedrock.

(3) Natural recharge to the aquifer occurs primarily through groundwater migration from Johnson Creek Valley which lies northwest of the Duck Lake basin.

(4) The aquifer is also artificially recharged through waters diverted to Duck Lake from Salmon and Johnson creeks by the Okanogan irrigation district and from waters incidental to irrigation of project lands.

(5) Since the basin retains substantial quantities of artificially stored groundwater, in accordance with chapter 90.44 RCW it has been recommended that the Duck Lake aquifer be designated as a groundwater subarea.