The department will organize and manage its daily water rights workload as established in subsections (1) through (5) of this section, except for applications processed under WAC 173-152-035.

(1) The department may establish regions and maintain regional offices or field offices for the purposes of maximizing the efficiency of its work. Regional offices and their geographic jurisdictions as of the effective date of this rule are as follows:

(a) Northwest regional office serving Island, King, Kitsap, San Juan, Skagit, Snohomish, and Whatcom counties.

(b) Southwest regional office serving Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, and Wahkiakum counties.

(c) Central regional office serving Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, and Yakima counties.

(d) Eastern regional office serving Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, and Whitman counties.

(2) The department will make decisions on applications within a region or within a regional or field office's geographic area in the order the applications were received except as allowed under RCW 90.03.380 (5)(c), and except as provided for in subsection (3) of this section and WAC 173-152-050.

(3) The department may, based on the criteria identified in subsection (5) of this section, conduct investigations and make decisions on one or more applications for the use of water from the same water source. A regional office may investigate more than one water source at a time.

(4) When the department investigates multiple applications for water from the same water source, it will make decisions in the order in which the applications were received, except as allowed under RCW 90.03.380 (5)(c) or provided for under WAC 173-152-050. The department will consider each application individually under the requirements of chapters 90.03, 90.38, 90.42, and 90.44 RCW, as applicable.

(5) Criteria for selecting a water source include, but are not limited to:

(a) The number and age of pending applications, and the quantities of water requested.

(b) The ability to efficiently investigate applications because of the availability of data related to water supply and future needs, stream flow needs for instream values, and hydrogeology of the basin.

(c) The ability of the department to support implementation of local land use plans or implementation of water resource plans.

(d) The projected population and economic growth in the area.

(e) The completion of an initial basin assessment as provided for in WAC 173-152-040(5).