ORS § 540.410
Whenever the owner, manager or lessee of a reservoir constructed under the provisions of the Water Rights Act, as defined in ORS 537.010, desires to use the bed of a stream, or other watercourse, to carry stored or impounded water from the reservoir to the consumer of the water, the owner, manager or lessee shall, in writing, notify the watermaster of the district in which the stored or impounded water from the reservoir is to be used, giving the date when it is proposed to discharge water from the reservoir, its volume, and the names of all persons and ditches entitled to its use. The watermaster shall then close, or so adjust the headgates of all ditches from the stream or watercourse, not entitled to the use of such stored water, as will enable those having the right to secure the volume to which they are entitled. The watermaster shall keep a true and just account of the time spent in the discharge of the watermaster's duties as defined in this section, and the Water Resources Commission shall present a bill of one-half the expense so incurred to the reservoir owner, manager or lessee. If the owner, manager or lessee neglects for 30 days, after presentation of the bill of costs, to pay it, the costs shall be made a charge upon the reservoir and the state shall have a preference lien therefor. Upon notice from the commission, the Attorney General shall foreclose the lien and collect the amount due, as provided in this section, in the same manner as other liens on real property are foreclosed.
ORS 540.410