Idaho Code § 42-606
All watermasters shall make an annual report to the department of water resources prior to the expiration of the watermaster's appointment for the current year. This report shall show the total volume of water delivered by the watermaster during the preceding year, the volume delivered to each water user, the total expense of delivery and the apportionment of expenses among users and all debits and credits to be carried over to the following year. Such report shall also include the number of days the watermaster and watermaster assistants have devoted to the distribution of such water and any records of stream flow the watermaster used or made in the process of distributing water supplies. The director may ask for other information deemed necessary in assuring proper distribution of water supplies within the district. The reports of watermasters to the department of water resources shall be filed and kept in the office of the department.
Idaho Code § 42-606