Section 37.03.12.040 - ALLOCATION OF NATURAL FLOW01.Administration of Surface Water Rights. Water not diverted or rotated for credit is available for the next in time water right. Natural flow rights are delivered to the point of diversion with no conveyance loss assessment. A natural flow water right delivered through a lateral or canal of a water conveyance entity shall be assessed the conveyance loss for the canal through which the water right is delivered.a. All water deliveries must be called for by the water user at least forty-eight (48) hours in advance of the actual water delivery. Water which can be delivered by the watermaster in less than forty-eight (48) hours may be used by the water user.b. The water user must notify the watermaster of the water users intent to use water as required by Rule Subsection 040.05.02.Rotation Credit. Water rights that do not include storage as a purpose of use may not be stored. Water rights whose source is Big Lost River with their point of diversion below the Mackay Dam may, however, be rotated for credit when such practice improves the efficiency of water use as contemplated by the Big Lost River Irrigation District's plan of operation subject to the following conditions: a. Rotation for credit must be approved by the director as provided by these rules.b. Rotation for credit must be pursuant to the Big Lost River Irrigation District's approved plan of operation.c. Any water credited under such a rotation, if not used in the same irrigation season in which it is credited, shall become storage water of the Big Lost River Irrigation District at the end of the irrigation season.d. Rotation for credit cannot occur prior to the need for irrigation water on the land, as determined pursuant to these rules, in any year. i. Natural flow must be available at the river headgate point of diversion for the water right requesting rotation credit.ii. The water user must have operable delivery and use facilities and an actual need for the water on the land in the year rotation is sought.iii. If natural flow can not be delivered to a point of diversion at the beginning of the irrigation season and the watermaster determines rotation credit is needed to make possible the delivery of water rights being called for, and there is room in Mackay Reservoir for rotation credit, the watermaster may rotate natural flow rights, which would not otherwise be deliverable to their point of diversion, for credit of up to a combined total of three thousand five hundred (3,500) AF to be released from the reservoir under the control of the watermaster to make natural flow rights deliverable to their point of diversion. The watermaster may use storage water to assist the delivery of natural flow water rights at the beginning of the irrigation season when requested to do so by the storage holder. e. Water rotated for credit may only be used on the land to which the water right being rotated is appurtenant (water rotated for credit may not be marketed) except under the provisions of Section 42-222A, Idaho Code.f. If the reservoir fills after rotation has begun in any year, (or would have filled except for flood operations) and the natural flow is sufficient to allow diversion of water by 1905 or junior water rights while the reservoir is full, all rotation credits accrued at that time are lost and all water in Mackay Reservoir at that time becomes storage water of the Big Lost River Irrigation District for reallocation. For purposes of this rule Mackay Reservoir will be considered full when the elevation of the water in the reservoir reaches or exceeds a four (4) day average of six thousand sixty-six and twelve one hundredths (6,066.12) feet MSL (spillway crest). Rotation for credit stops at the time Mackay Reservoir fills, and while it remains full, but if the natural flow does not increase sufficiently to allow 1905 or junior water rights to divert after the reservoir fills the rotation credit in the reservoir shall remain the credit of the water user(s) who accrued the rotation credit.g. Water rights being rotated must be identified to the watermaster as being rotated into Mackay Reservoir. Water rights identified as such will have the Mackay Reservoir as the temporary point of diversion during the time rotation is occurring.h. The rate of diversion for a water right being rotated for credit combined with other water rights for the same place of use being diverted at the same time cannot exceed the combined diversion limit specified in the listing of water rights. This rule does not limit the rate at which rotation credit, once impounded, can be used.03.Assessment of Evaporation and Conveyance Losses to Impounded Water.a. Evaporation losses from Mackay Reservoir shall be estimated daily by the watermaster by applying correlated evapotranspiration data and shall be assessed to all impounded water.b. Conveyance losses in the natural channel shall be proportioned by the watermaster between natural flow and impounded water. The proportioning shall be done on a river reach basis. Impounded water flowing through a river reach that does not have a conveyance loss will not be assessed a loss for that reach. Impounded water flowing through any river reach that does have a conveyance loss will be assessed the proportionate share of the loss for each losing reach through which the impounded water flows.i. An exception is made for impounded water delivered through the Beck and Evan diversion located in the SW1/4SE1/4SW1/4, Section 11, Township 6 North, Range 25 East, B.M. Conveyance loss for this impounded water will be assessed the conveyance loss of the Leslie reach, if any, and the additional conveyance loss to the Beck and Evan diversion but not the conveyance loss of the entire Moore reach.04.Initiation and Duration of Surface Water Allocation for Irrigation. Any time after May 1 an irrigation water user can make a delivery call on the natural flow if the water user can make beneficial use of the water for irrigation. If sufficient natural flow exists to deliver the called for water right in a useable amount to the water users place of use, the watermaster shall deliver the right. In addition, the director may allow the diversion of rights or portions of rights for irrigation use from the Big Lost River as early as April 20 and as late as October 31, and from surface water tributaries to the Big Lost River either before or after the period of use for irrigation described in the water right where:a. The water so diverted is applied to a beneficial use resulting in an immediate benefit to growing plants or is necessary to allow performance of an agricultural practice generally accepted in the community, as determined by the director.b. All surface water rights, regardless of priority, unless subordinated to the water right or class of rights being called for, (now existing or developed subsequent to these rules), existing at the time of diversion that are within their period of use can be satisfied.c. The diversion and use of the water does not conflict with the public interest as determined by the director.05.Notice to Initiate Delivery. Water users must initiate delivery of their water right(s) by notifying the watermaster that they are ready to put water to beneficial use.06.Diversion of Additional Flows. The director may allow the diversion of surface water in addition to the quantity of surface water described in a water right for irrigation use to be diverted for irrigation of the described place of use where:a. The waters so diverted are applied to a beneficial use, as determined by the director.b. All surface water rights, regardless of priority, unless subordinated to the water right or class of water rights being called for, (now existing or developed subsequent to these rules), existing at the time of diversion that are within their period of use can be satisfied.c. The diversion and use of the water does not conflict with the public interest as determined by the director.d. Additional flows diverted pursuant to Rule 040.06 are natural flows and will not be assessed as impounded water.07.Mackay Dam Minimum By-Pass. Mackay Dam and Reservoir shall be operated to maintain a minimum flow of fifty (50) CFS at the 2-B gage.08.Canal or Lateral Delivery. In the event a water user feels inappropriate delivery of natural flow water is occurring on any lateral or canal, the water user can request the watermaster to investigate. In the event the watermaster determines that delivery of natural flow water rights within a lateral or canal is being improperly conducted he shall: a. Notify the ditch rider and the water delivery entity of the results of his investigation and coordinate efforts to make proper delivery of the natural flow.b. If the situation has not been sufficiently resolved within twenty-four (24) hours the watermaster will notify the director who may take all actions authorized by law to remedy the situation.Idaho Admin. Code r. 37.03.12.040