(2) Rates for the uses of water mentioned in this section may be fixed by the Legislative Assembly or by such officer as may be given that authority by the Legislative Assembly, but rates shall not be fixed lower than will allow the net profits of any ditch, canal, flume or system thereof to equal the prevailing legal rate of interest on the amount of money actually paid in and employed in the construction and operation of the ditch, canal, flume or system.
(3) This section and ORS 541.020 to 541.080 may at any time be amended by the Legislative Assembly, and commissioners for the management of water rights and the use of water may be appointed.