(1) Upon the receipt of adjudication claims and the filing of claimants' evidence, the department shall conduct a preliminary investigation for the purpose of examining:

(a) The uses of the subject waters by and any physical works in connection with the persons to whom the adjudication applies; and

(b) The uses for which a statement of claim has been filed under chapter 90.14 RCW or for which the department has a permit or certificate of water right on record.

(2)(a) The examination may include, as the department deems appropriate:

(i) An estimation of the amount of water that is reasonably necessary to accomplish various beneficial uses within the area;

(ii) The measurement of streamflows;

(iii) The measurement of any diversion or withdrawal rates;

(iv) An estimation of storage capacity and the amount of water stored;

(v) The types and numbers of stock watered;

(vi) The number of residences served;

(vii) The location and size of any irrigated land areas; and

(viii) Any other information pertinent to the determination of water rights in an adjudication under this chapter.

(b) The department may also take other necessary steps and gather other data and information as may be essential to the proper understanding of the water uses and associated rights of the affected water users, including review of each claimant's adjudication claim and evidence the claimant filed to support the claim. The claimants and the department are encouraged to confer as may be beneficial to clarify the factual and legal basis for the claim. To the extent consistent with court rules, the court may deem it appropriate to encourage claimants and the department to work closely together to reach agreement on a claimed water right that may result in timely settlement of water rights, reduced costs for the parties, greater equity and general public service, and better information that may be used for overall water management.

(3) The department shall file with the court the department's report of findings as to each adjudication claim filed timely under RCW 90.03.140. The department may divide its report of findings into two or more segments, covering particular drainages, uses, or other appropriate bases for dividing the report on adjudication claims. Based on the evidence filed by claimants and the department's report of findings, the department shall file with the superior court either or both of the following motions:

(a) A motion for a partial decree in favor of all stated claims under RCW 90.03.140 that the department finds to be substantiated with factual evidence; or

(b) A motion seeking determination of contested claims before the court.

Application—2009 c 332: See note following RCW 90.03.110.