(1) The department may conduct assessments to assemble and compare information related to:

(a) Water use;

(b) Water availability;

(c) The quantity of water allocated to existing rights;

(d) Known or potential water rights not recorded within the state water right record, and claims to water rights including those recorded within the water rights claims registry;

(e) Instream flow; and

(f) The hydrology of a basin.

(2)The department may also enter into agreements or contracts with public or private parties to conduct assessments.

(3) In cooperation with federal, state, tribal, and local jurisdictions and other interested parties, each regional office and the department in processing applications under chapter 90.90 RCW will consider assessing a geographic area or water source within its service area using criteria such as:

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

(b) The projected population, growth and off-stream needs for water in the area.

(c) Known water quality problems.

(d) Existence of distressed or endangered fish stocks.

(e) Risk of impairment to senior rights (including instream flow rights).

(f) Availability of data related to water supply and future need, stream flow needs for instream values, and hydrogeology of the basin.

(g) The number of claims to water rights submitted pursuant to chapter 90.14 RCW.

(h) The ability of the department to support local land use activities.

(4) Each regional office and the department in processing applications under chapter 90.90 RCW may conduct multiple basin assessments at the same time. When the department determines conducting a basin assessment is in the public interest, it will:

(a) Publish notice of the intent to conduct a basin assessment once a week, for two consecutive weeks in a newspaper of general circulation within the geographic area.

(b) Notify any Indian tribe with potential interest in the basin of the intent.

(c) Temporarily cease making decisions on all competing water right applications in the basin proposed for assessment until the initial basin assessment is complete and published except for applications prioritized pursuant to WAC 173-152-050.

(d) Make decisions on competing applications after the initial basin assessment is complete and published to the extent sufficient information is available.

(5) Initial basin or water source assessments will be conducted to assemble the following existing information:

(a) Physical characterization of the watershed related to:

(i) Climatic impacts to water resources.

(ii) Geology.

(iii) Stream flow trends.

(iv) Groundwater elevation trends and the contribution of groundwater to stream flows.

(v) Surface and groundwater quality in the basin or water source.

(b) Out-of-stream water use characterization related to:

(i) Water rights, federal rights, and claims to water rights.

(ii) Estimated use of water pursuant to water rights and claims to water rights.

(iii) Water use pursuant to RCW 90.44.050.

(iv) Extent of unauthorized water use.

(v) Potential future demands for out-of-stream water use in the basin.

(c) Instream water use characterization related to:

(i) National Pollution Discharge Elimination System permits and the need for instream flow for pollution assimilation;

(ii) Fish stocks and habitat requirements, including existing, defined or engineered, or approved restoration projects;

(iii) Wildlife habitat requirements;

(iv) Recreational requirements; and

(v) Water rights and claims to water rights.

(6) Upon completion and publication of the initial basin assessment, the department will consult with the public and federal, state, tribal, local jurisdictions and interested parties to evaluate the basin assessment. The evaluation will assess the data, analysis, and presentation of information in the basin assessment in terms of quality, adequacy, and utility to make decisions on future water resource allocation and use.

(7) The department will make decisions on competing applications for water from a water source within the basin where sufficient information for water resource allocation exists. If the department determines that the information assembled and compared is not sufficient, the department may withdraw the water source from appropriation pursuant to RCW 90.54.050(2). The department in consultation with the public, federal, state, tribal, local jurisdictions and interested parties will design and conduct additional investigations, to the extent resources allow, to obtain the information necessary to make future decisions on water allocation and use.

(8) The department shall make available online information obtained and compiled during an initial basin assessment of the water resources in a basin or water source.