IDAPA 37.03.11
General Public.
These rules establish the procedures to regulate the distribution of water from the streams, rivers, lakes, ground water and other natural water sources as necessary to carry out the laws in accordance with the priorities of the rights of the users thereof.
This rule implements the following statutes passed by the Idaho Legislature:
Appropriation of Water -
General Provisions:
Distribution of Water Among Appropriators:
Headgates and Measuring Devices:
Idaho Department of Water Resources 322 East Front Street P.O. Box 83720 Boise, ID 83720
Phone: (208) 287-4800 Email: mathew.weaver@idwr.idaho.gov Website: idwr.idaho.gov
This rule chapter will be reviewed in compliance with Section 67-5292, Idaho Code, and in accordance with the 8-year rule review schedule linked here.
37.03.11 – Rules for Conjunctive Management of Surface and Ground Water Resources
000. Legal Authority (Rule 0). ... 3
001. Scope (Rule 1). ... 3
002. Other Authorities Remain Applicable (Rule 2). ... 3
003. -- 009. (Reserved) ... 3
010. Definitions (Rule 10). ... 3
011. -- 019. (Reserved) ... 5
020. General Statements Of Purpose And Policies For Conjunctive Management Of Surface And Ground Water Resources (Rule 20). ... 5
021. -- 029. (Reserved) ... 6
030. Responses To Calls For Water Delivery In An Unorganized Water District Or With No Ground Water Regulation (Rule 30). ... 6
031. Determining Areas Having A Common Ground Water Supply (Rule 31). ... 8
032. -- 039. (Reserved) ... 8
040. Responses To Calls For Water Delivery In An Organized Water District (Rule 40). ... 8
041. Administration Of Diversion And Use Of Water Within A Ground Water Management Area (Rule 41). ... 10
042. Determining Material Injury And Reasonableness Of Water Diversions (Rule 42). ... 10
043. Mitigation Plans (Rule 43). ... 11
044. -- 049. (Reserved) ... 12
050. Areas Determined To Have A Common Ground Water Supply (Rule 50). ... 13
051. -- 999. (Reserved) ... 13
These rules are promulgated pursuant to Chapter 52, Title 67, Idaho Code, the Idaho Administrative Procedure Act, and Section 42-603, Idaho Code, which provides that the Director of the Department of Water Resources is authorized to adopt rules and regulations for the distribution of water from the streams, rivers, lakes, ground water and other natural water sources as necessary to carry out the laws in accordance with the priorities of the rights of the users thereof. These rules are also issued pursuant to Section 42-1805(8), Idaho Code, which provides the Director with authority to promulgate rules implementing or effectuating the powers and duties of the department. (3-31-22)
The rules prescribe procedures for responding to a delivery call made by the holder of a senior-priority surface or ground water right against the holder of a junior-priority ground water right in an area having a common ground water supply. It is intended that these rules be incorporated into general rules governing water distribution in Idaho when such rules are adopted subsequently. (3-31-22)
Nothing in these rules limits the Director's authority to take alternative or additional actions relating to the management of water resources as provided by Idaho law. (3-31-22)
For the purposes of these rules, the following terms will be used as defined below. (3-31-22)
01. Area Having a Common Ground Water Supply. A ground water source within which the diversion and use of ground water or changes in ground water recharge affect the flow of water in a surface water source or within which the diversion and use of water by a holder of a ground water right affects the ground water supply available to the holders of other ground water rights. (Section 42-237a.g., Idaho Code) (3-31-22)
02. Artificial Ground Water Recharge. A deliberate and purposeful activity or project that is performed in accordance with Section 42-234(2), Idaho Code, and that diverts, distributes, injects, stores or spreads water to areas from which such water will enter into and recharge a ground water source in an area having a common ground water supply. (3-31-22)
03. Conjunctive Management. Legal and hydrologic integration of administration of the diversion and use of water under water rights from surface and ground water sources, including areas having a common ground water supply. (3-31-22)
04. Delivery Call. A request from the holder of a water right for administration of water rights under the prior appropriation doctrine. (3-31-22)
05. Department. The Department of Water Resources created by Section 42-1701, Idaho Code. (3-31-22)
06. Director. The Director of the Department of Water Resources appointed as provided by Section 42-1801, Idaho Code, or an employee, hearing officer or other appointee of the Department who has been delegated to act for the Director as provided by Section 42-1701, Idaho Code. (3-31-22)
07. Full Economic Development of Underground Water Resources. The diversion and use of water from a ground water source for beneficial uses in the public interest at a rate that does not exceed the reasonably anticipated average rate of future natural recharge, in a manner that does not result in material injury to senior-priority surface or ground water rights, and that furthers the principle of reasonable use of surface and ground water as set forth in Rule 42. (3-31-22)
08. Futile Call. A delivery call made by the holder of a senior-priority surface or ground water right that, for physical and hydrologic reasons, cannot be satisfied within a reasonable time of the call by immediately curtailing diversions under junior-priority ground water rights or that would result in waste of the water resource. (3-31-22)
09. Ground Water Management Area. Any ground water basin or designated part thereof as designated by the Director pursuant to Section 42-233(b), Idaho Code. (3-31-22)
10. Ground Water. Water under the surface of the ground whatever may be the geological structure in which it is standing or moving as provided in Section 42-230(a), Idaho Code. (3-31-22)
11. Holder of a Water Right. The legal or beneficial owner or user pursuant to lease or contract of a right to divert or to protect in place surface or ground water of the state for a beneficial use or purpose. (3-31-22)
12. Idaho Law. The constitution, statutes, administrative rules and case law of Idaho. (3-31-22)
13. Junior-Priority. A water right priority date later in time than the priority date of other water rights being considered. (3-31-22)
14. Material Injury. Hindrance to or impact upon the exercise of a water right caused by the use of water by another person as determined in accordance with Idaho Law, as set forth in Rule 42. (3-31-22)
15. Mitigation Plan. A document submitted by the holder(s) of a junior-priority ground water right and approved by the Director as provided in Rule 043 that identifies actions and measures to prevent, or compensate holders of senior-priority water rights for, material injury caused by the diversion and use of water by the holders of junior-priority ground water rights within an area having a common ground water supply. (3-31-22)
16. Person. Any individual, partnership, corporation, association, governmental subdivision or agency, or public or private organization or entity of any character. (3-31-22)
17. Petitioner. Person who asks the Department to initiate a contested case or to otherwise take action that will result in the issuance of an order or rule. (3-31-22)
18. Reasonable Ground Water Pumping Level. A level established by the Director pursuant to Sections 42-226, and 42-237a.g., Idaho Code, either generally for an area or aquifer or for individual water rights on a case-by-case basis, for the purpose of protecting the holders of senior-priority ground water rights against unreasonable lowering of ground water levels caused by diversion and use of surface or ground water by the holders of junior-priority surface or ground water rights under Idaho law. (3-31-22)
19. Reasonably Anticipated Average Rate of Future Natural Recharge. The estimated average annual volume of water recharged to an area having a common ground water supply from precipitation, underflow from tributary sources, and stream losses and also water incidentally recharged to an area having a common ground water supply as a result of the diversion and use of water for irrigation and other purposes. The estimate will be based on available data regarding conditions of diversion and use of water existing at the time the estimate is made and may vary as these conditions and available information change. (3-31-22)
20. Respondent. Persons against whom complaints or petitions are filed or about whom investigations are initiated. (3-31-22)
21. Senior-Priority. A water right priority date earlier in time than the priority dates of other water rights being considered. (3-31-22)
22. Surface Water. Rivers, streams, lakes and springs when flowing in their natural channels as provided in Sections 42-101 and 42-103, Idaho Code. (3-31-22)
23. Water District. An instrumentality of the state of Idaho created by the Director as provided in Section 42-604, Idaho Code, for the purpose of performing the essential governmental function of distribution of water among appropriators under Idaho law. (3-31-22)
24. Watermaster. A person elected and appointed as provided in Section 42-605, and Section 42-801, Idaho Code, to distribute water within a water district. (3-31-22)
25. Water Right. The legal right to divert and use or to protect in place the public waters of the state of Idaho where such right is evidenced by a decree, a permit or license issued by the Department, a beneficial or
constitutional use right or a right based on federal law.
(3-31-22)
01. Distribution of Water Among the Holders of Senior and Junior-Priority Rights. These rules apply to all situations in the state where the diversion and use of water under junior-priority ground water rights either individually or collectively causes material injury to uses of water under senior-priority water rights. The rules govern the distribution of water from ground water sources and areas having a common ground water supply. (3-31-22)
02. Prior Appropriation Doctrine. These rules acknowledge all elements of the prior appropriation doctrine as established by Idaho law. (3-31-22)
03. Reasonable Use of Surface and Ground Water. These rules integrate the administration and use of surface and ground water in a manner consistent with the traditional policy of reasonable use of both surface and ground water. The policy of reasonable use includes the concepts of priority in time and superiority in right being subject to conditions of reasonable use as the legislature may by law prescribe as provided in Article XV, Section 5, Idaho Constitution, optimum development of water resources in the public interest prescribed in Article XV, Section 7, Idaho Constitution, and full economic development as defined by Idaho law. An appropriator is not entitled to command the entirety of large volumes of water in a surface or ground water source to support his appropriation contrary to the public policy of reasonable use of water as described in this rule. (3-31-22)
04. Delivery Calls. These rules provide the basis and procedure for responding to delivery calls made by the holder of a senior-priority surface or ground water right against the holder of a junior-priority ground water right. The principle of the futile call applies to the distribution of water under these rules. Although a call may be denied under the futile call doctrine, these rules may require mitigation or staged or phased curtailment of a junior-priority use if diversion and use of water by the holder of the junior-priority water right causes material injury, even though not immediately measurable, to the holder of a senior-priority surface or ground water right in instances where the hydrologic connection may be remote, the resource is large and no direct immediate relief would be achieved if the junior-priority water use was discontinued. (3-31-22)
05. Exercise of Water Rights. These rules provide the basis for determining the reasonableness of the diversion and use of water by both the holder of a senior-priority water right who requests priority delivery and the holder of a junior-priority water right against whom the call is made. (3-31-22)
06. Areas Having a Common Ground Water Supply. These rules provide the basis for the designation of areas of the state that have a common ground water supply and the procedures that will be followed in incorporating the water rights within such areas into existing water districts or creating new districts as provided in Section 42-237a.g., and Section 42-604, Idaho Code, or designating such areas as ground water management areas as provided in Section 42-233(b), Idaho Code. (3-31-22)
07. Sequence of Actions for Responding to Delivery Calls. Rule 30 provides procedures for responding to delivery calls within areas having a common ground water supply that have not been incorporated into an existing or new water district or designated a ground water management area. Rule 40 provides procedures for responding to delivery calls within water districts where areas having a common ground water supply have been incorporated into the district or a new district has been created. Rule 41 provides procedures for responding to delivery calls within areas that have been designated as ground water management areas. Rule 50 designates specific known areas having a common ground water supply within the state. (3-31-22)
08. Reasonably Anticipated Average Rate of Future Natural Recharge. These rules provide for administration of the use of ground water resources to achieve the goal that withdrawals of ground water not exceed the reasonably anticipated average rate of future natural recharge. (Section 42-237a.g., Idaho Code) (3-31-22)
09. Saving of Defenses. Nothing in these rules affects or in any way limit any person’s entitlement to assert any defense or claim based upon fact or law in any contested case or other proceeding. (3-31-22)
10. Wells as Alternate or Changed Points of Diversion for Water Rights from a Surface Water Source. Nothing in these rules prohibits any holder of a water right from a surface water source from seeking, pursuant to Idaho law, to change the point of diversion of the water to an inter-connected area having a common ground water supply. (3-31-22)
11. Domestic and Stock Watering Ground Water Rights Exempt. A delivery call shall not be effective against any ground water right used for domestic purposes regardless of priority date where such domestic use is within the limits of the definition set forth in Section 42-111, Idaho Code, nor against any ground water right used for stock watering where such stock watering use is within the limits of the definition set forth in Section 42-1401A(11), Idaho Code; provided, however, this exemption shall not prohibit the holder of a water right for domestic or stock watering uses from making a delivery call, including a delivery call against the holders of other domestic or stockwatering rights, where the holder of such right is suffering material injury. (3-31-22)
021. -- 029. (RESERVED)
Responses to calls for water delivery made by the holders of senior-priority surface or ground water rights against the holders of junior-priority ground water rights within areas of the state not in organized water districts or within water districts where ground water regulation has not been included in the functions of such districts or within areas that have not been designated ground water management areas shall be as follows: (3-31-22)
01. Delivery Call (Petition). When a delivery call is made by the holder of a surface or ground water right (petitioner) alleging that by reason of diversion of water by the holders of one (1) or more junior-priority ground water rights (respondents) the petitioner is suffering material injury, the petitioner shall file with the Director a petition in writing containing, at least, the following in addition to the information required by IDAPA 37.01.01, “Rules of Procedure of the Department of Water Resources,” Rule 230: (3-31-22)
a. A description of the water rights of the petitioner including a listing of the decree, license, permit, claim or other documentation of such right, the water diversion and delivery system being used by petitioner and the beneficial use being made of the water. (3-31-22)
b. The names, addresses and description of the water rights of the ground water users (respondents) who are alleged to be causing material injury to the rights of the petitioner in so far as such information is known by the petitioner or can be reasonably determined by a search of public records. (3-31-22)
c. All information, measurements, data or study results available to the petitioner to support the claim of material injury. (3-31-22)
d. A description of the area having a common ground water supply within which petitioner desires junior-priority ground water diversion and use to be regulated. (3-31-22)
02. Contested Case. The Department will consider the matter as a petition for contested case under the Department’s Rules of Procedure, IDAPA 37.01.01. The petitioner shall serve the petition upon all known respondents as required by IDAPA 37.01.01, “Rules of Procedure of the Department of Water Resources,” Rule 203. In addition to such direct service by petitioner, the Department will give such general notice by publication or news release as will advise ground water users within the petitioned area of the matter. (3-31-22)
03. Informal Resolution. The Department may initially consider the contested case for informal resolution under the provisions of Section 67-5241, Idaho Code, if doing so will expedite the case without prejudicing the interests of any party. (3-31-22)
04. Petition for Modification of an Existing Water District. In the event the petition proposes regulation of ground water rights conjunctively with surface water rights in an organized water district, and the water rights have been adjudicated, the Department may consider such to be a petition for modification of the organized water district and notice of proposed modification of the water district shall be provided by the Director pursuant to
Section 42-604, Idaho Code. The Department will proceed to consider the matter addressed by the petition under the Department’s Rules of Procedure. (3-31-22)
05. Petition for Creation of a New Water District. In the event the petition proposes regulation of ground water rights from a ground water source or conjunctively with surface water rights within an area having a common ground water supply which is not in an existing water district, and the water rights have been adjudicated, the Department may consider such to be a petition for creation of a new water district and notice of proposed creation of a water district shall be provided by the Director pursuant to Section 42-604, Idaho Code. The Department will proceed to consider the matter under the Department’s Rules of Procedure. (3-31-22)
06. Petition for Designation of a Ground Water Management Area. In the event the petition proposes regulation of ground water rights from an area having a common ground water supply within which the water rights have not been adjudicated, the Department may consider such to be a petition for designation of a ground water management area pursuant to Section 42-233(b), Idaho Code. The Department will proceed to consider the matter under the Department’s Rules of Procedure. (3-31-22)
07. Order. Following consideration of the contested case under the Department’s Rules of Procedure, the Director may, by order, take any or all of the following actions: (3-31-22)
a. Deny the petition in whole or in part; (3-31-22)
b. Grant the petition in whole or in part or upon conditions; (3-31-22)
c. Determine an area having a common ground water supply which affects the flow of water in a surface water source in an organized water district; (3-31-22)
d. Incorporate an area having a common ground water supply into an organized water district following the procedures of Section 42-604, Idaho Code, provided that the ground water rights that would be incorporated into the water district have been adjudicated relative to the rights already encompassed within the district; (3-31-22)
e. Create a new water district following the procedures of Section 42-604, Idaho Code, provided that the water rights to be included in the new water district have been adjudicated; (3-31-22)
f. Determine the need for an adjudication of the priorities and permissible rates and volumes of diversion and consumptive use under the surface and ground water rights of the petitioner and respondents and initiate such adjudication pursuant to Section 42-1406, Idaho Code; (3-31-22)
g. By summary order as provided in Section 42-237 a.g., Idaho Code, prohibit or limit the withdrawal of water from any well during any period it is determined that water to fill any water right is not there available without causing ground water levels to be drawn below the reasonable ground water pumping level, or would affect the present or future use of any prior surface or ground water right or result in the withdrawing of the ground water supply at a rate beyond the reasonably anticipated average rate of future natural recharge. The Director will take into consideration the existence of any approved mitigation plan before issuing any order prohibiting or limiting withdrawal of water from any well; or (3-31-22)
h. Designate a ground water management area under the provisions of Section 42-233(b), Idaho Code, if it appears that administration of the diversion and use of water from an area having a common ground water supply is required because the ground water supply is insufficient to meet the demands of water rights or the diversion and use of water is at a rate beyond the reasonably anticipated average rate of future natural recharge and modification of an existing water district or creation of a new water district cannot be readily accomplished due to the need to first obtain an adjudication of the water rights. (3-31-22)
08. Orders for Interim Administration. For the purposes of Rule Subsections 030.07.d. and 030.07.e., an outstanding order for interim administration of water rights issued by the court pursuant to Section 42-1417, Idaho Code, in a general adjudication proceeding shall be considered as an adjudication of the water rights involved. (3-31-22)
09. Administration Pursuant to Rule 40. Upon a finding of an area of common ground water supply and upon the incorporation of such area into an organized water district, or the creation of a new water district, the use of water shall be administered in accordance with the priorities of the various water rights as provided in Rule 40. (3-31-22)
10. Administration Pursuant to Rule 41. Upon the designation of a ground water management area, the diversion and use of water within such area shall be administered in accordance with the priorities of the various water rights as provided in Rule 41. (3-31-22)
01. Director to Consider Information. The Director will consider all available data and information that describes the relationship between ground water and surface water in making a finding of an area of common ground water supply. (3-31-22)
02. Kinds of Information. The information considered may include, but is not limited to, any or all of the following: (3-31-22)
a. Water level measurements, studies, reports, computer simulations, pumping tests, hydrographs of stream flow and ground water levels and other such data; and (3-31-22)
b. The testimony and opinion of expert witnesses at a hearing on a petition for expansion of a water district or organization of a new water district or designation of a ground water management area. (3-31-22)
03. Criteria for Findings. A ground water source will be determined to be an area having a common ground water supply if: (3-31-22)
a. The ground water source supplies water to or receives water from a surface water source; or (3-31-22)
b. Diversion and use of water from the ground water source will cause water to move from the surface water source to the ground water source. (3-31-22)
c. Diversion and use of water from the ground water source has an impact upon the ground water supply available to other persons who divert and use water from the same ground water source. (3-31-22)
04. Reasonably Anticipated Average Rate of Future Natural Recharge. The Director will estimate the reasonably anticipated average rate of future natural recharge for an area having a common ground water supply. Such estimates will be made and updated periodically as new data and information are available and conditions of diversion and use change. (3-31-22)
05. Findings. The findings of the Director will be included in the Order issued pursuant to Rule Subsection 030.07. (3-31-22)
Responses to calls for water delivery made by the holders of senior-priority surface or ground water rights against the holders of junior-priority ground water rights from areas having a common ground water supply in an organized water district shall be as follows: (3-31-22)
01. Responding to a Delivery Call. When a delivery call is made by the holder of a senior-priority water right (petitioner) alleging that by reason of diversion of water by the holders of one (1) or more junior-priority ground water rights (respondents) from an area having a common ground water supply in an organized water district the petitioner is suffering material injury, and upon a finding by the Director as provided in Rule 42 that material
injury is occurring, the Director, through the watermaster, shall: (3-31-22)
a. Regulate the diversion and use of water in accordance with the priorities of rights of the various surface or ground water users whose rights are included within the district, provided, that regulation of junior-priority ground water diversion and use where the material injury is delayed or long range may, by order of the Director, be phased-in over not more than a five-year (5) period to lessen the economic impact of immediate and complete curtailment; or (3-31-22)
b. Allow out-of-priority diversion of water by junior-priority ground water users pursuant to a mitigation plan that has been approved by the Director. (3-31-22)
02. Regulation of Uses of Water by Watermaster. The Director, through the watermaster, shall regulate use of water within the water district pursuant to Idaho law and the priorities of water rights as provided in Section 42-604, Idaho Code, and under the following procedures: (3-31-22)
a. The watermaster shall determine the quantity of surface water of any stream included within the water district which is available for diversion and shall shut the headgates of the holders of junior-priority surface water rights as necessary to assure that water is being diverted and used in accordance with the priorities of the respective water rights from the surface water source. (3-31-22)
b. The watermaster shall regulate the diversion and use of ground water in accordance with the rights thereto, approved mitigation plans and orders issued by the Director. (3-31-22)
c. Where a call is made by the holder of a senior-priority water right against the holder of a junior-priority ground water right in the water district the watermaster shall first determine whether a mitigation plan has been approved by the Director whereby diversion of ground water may be allowed to continue out of priority order. If the holder of a junior-priority ground water right is a participant in such approved mitigation plan, and is operating in conformance therewith, the watermaster shall allow the ground water use to continue out of priority. (3-31-22)
d. The watermaster shall maintain records of the diversions of water by surface and ground water users within the water district and records of water provided and other compensation supplied under the approved mitigation plan which shall be compiled into the annual report which is required by Section 42-606, Idaho Code. (3-31-22)
e. Under the direction of the Department, watermasters of separate water districts shall cooperate and reciprocate in assisting each other in assuring that diversion and use of water under water rights is administered in a manner to assure protection of senior-priority water rights provided the relative priorities of the water rights within the separate water districts have been adjudicated. (3-31-22)
03. Reasonable Exercise of Rights. In determining whether diversion and use of water under rights will be regulated under Rule Subsection 040.01.a. or 040.01.b., the Director shall consider whether the petitioner making the delivery call is suffering material injury to a senior-priority water right and is diverting and using water efficiently and without waste, and in a manner consistent with the goal of reasonable use of surface and ground waters as described in Rule 42. The Director will also consider whether the respondent junior-priority water right holder is using water efficiently and without waste. (3-31-22)
04. Actions of the Watermaster Under a Mitigation Plan. Where a mitigation plan has been approved as provided in Rule 42, the watermaster may permit the diversion and use of ground water to continue out of priority order within the water district provided the holder of the junior-priority ground water right operates in accordance with such approved mitigation plan. (3-31-22)
05. Curtailment of Use Where Diversions Not in Accord With Mitigation Plan or Mitigation Plan Is Not Effective. Where a mitigation plan has been approved and the junior-priority ground water user fails to operate in accordance with such approved plan or the plan fails to mitigate the material injury resulting from diversion and use of water by holders of junior-priority water rights, the watermaster will notify the Director who will immediately issue cease and desist orders and direct the watermaster to terminate the out-of-priority use of ground water rights otherwise benefiting from such plan or take such other actions as provided in the mitigation plan to ensure protection
of senior-priority water rights.
(3-31-22)
06. Collection of Assessments Within Water District. Where a mitigation plan has been approved, the watermaster of the water district shall include the costs of administration of the plan within the proposed annual operation budget of the district; and, upon approval by the water users at the annual water district meeting, the water district shall provide for the collection of assessment of ground water users as provided by the plan, collect the assessments and expend funds for the operation of the plan; and the watermaster shall maintain records of the volumes of water or other compensation made available by the plan and the disposition of such water or other compensation. (3-31-22)
01. Responding to a Delivery Call. When a delivery call is made by the holder of a senior-priority ground water right against holders of junior-priority ground water rights in a designated ground water management area alleging that the ground water supply is insufficient to meet the demands of water rights within all or portions of the ground water management area and requesting the Director to order water right holders, on a time priority basis, to cease or reduce withdrawal of water, the Director shall proceed as follows: (3-31-22)
a. The petitioner shall be required to submit all information available to petitioner on which the claim is based that the water supply is insufficient. (3-31-22)
b. The Director will conduct a fact-finding hearing on the petition at which the petitioner and respondents may present evidence on the water supply, and the diversion and use of water from the ground water management area. (3-31-22)
02. Order. Following the hearing, the Director may take any or all of the following actions: (3-31-22)
a. Deny the petition in whole or in part; (3-31-22)
b. Grant the petition in whole or in part or upon conditions; (3-31-22)
c. Find that the water supply of the ground water management area is insufficient to meet the demands of water rights within all or portions of the ground water management area and order water right holders on a time priority basis to cease or reduce withdrawal of water, provided that the Director shall consider the expected benefits of an approved mitigation plan in making such finding. (3-31-22)
d. Require the installation of measuring devices and the reporting of water diversions pursuant to Section 42-701, Idaho Code. (3-31-22)
03. Date and Effect of Order. Any order to cease or reduce withdrawal of water will be issued prior to September 1 and shall be effective for the growing season during the year following the date the order is given and until such order is revoked or modified by further order of the Director. (3-31-22)
04. Preparation of Water Right Priority Schedule. For the purposes of the Order provided in Rule Subsections 041.02 and 041.03, the Director will utilize all available water right records, claims, permits, licenses and decrees to prepare a water right priority schedule. (3-31-22)
01. Factors. Factors the Director may consider in determining whether the holders of water rights are suffering material injury and using water efficiently and without waste include, but are not limited to, the following: (3-31-22)
a. The amount of water available in the source from which the water right is diverted. (3-31-22)
b. The effort or expense of the holder of the water right to divert water from the source. (3-31-22)
c. Whether the exercise of junior-priority ground water rights individually or collectively affects the quantity and timing of when water is available to, and the cost of exercising, a senior-priority surface or ground water right. This may include the seasonal as well as the multi-year and cumulative impacts of all ground water withdrawals from the area having a common ground water supply. (3-31-22)
d. If for irrigation, the rate of diversion compared to the acreage of land served, the annual volume of water diverted, the system diversion and conveyance efficiency, and the method of irrigation water application. (3-31-22)
e. The amount of water being diverted and used compared to the water rights. (3-31-22)
f. The existence of water measuring and recording devices. (3-31-22)
g. The extent to which the requirements of the holder of a senior-priority water right could be met with the user’s existing facilities and water supplies by employing reasonable diversion and conveyance efficiency and conservation practices; provided, however, the holder of a surface water storage right shall be entitled to maintain a reasonable amount of carry-over storage to assure water supplies for future dry years. In determining a reasonable amount of carry-over storage water, the Director shall consider the average annual rate of fill of storage reservoirs and the average annual carry-over for prior comparable water conditions and the projected water supply for the system. (3-31-22)
h. The extent to which the requirements of the senior-priority surface water right could be met using alternate reasonable means of diversion or alternate points of diversion, including the construction of wells or the use of existing wells to divert and use water from the area having a common ground water supply under the petitioner’s surface water right priority. (3-31-22)
02. Delivery Call for Curtailment of Pumping. The holder of a senior-priority surface or ground water right will be prevented from making a delivery call for curtailment of pumping of any well used by the holder of a junior-priority ground water right where use of water under the junior-priority right is covered by an approved and effectively operating mitigation plan. (3-31-22)
01. Submission of Mitigation Plans. A proposed mitigation plan shall be submitted to the Director in writing and contain the following information: (3-31-22)
a. The name and mailing address of the person or persons submitting the plan. (3-31-22)
b. Identification of the water rights for which benefit the mitigation plan is proposed. (3-31-22)
c. A description of the plan setting forth the water supplies proposed to be used for mitigation and any circumstances or limitations on the availability of such supplies. (3-31-22)
d. Such information as will allow the Director to evaluate the factors set forth in Rule Subsection 043.03. (3-31-22)
02. Notice and Hearing. Upon receipt of a proposed mitigation plan the Director will provide notice, hold a hearing as determined necessary, and consider the plan under the procedural provisions of Section 42-222, Idaho Code, in the same manner as applications to transfer water rights. (3-31-22)
03. Factors to Be Considered. Factors that may be considered by the Director in determining whether a proposed mitigation plan will prevent injury to senior rights include, but are not limited to, the following: (3-31-22)
a. Whether delivery, storage and use of water pursuant to the mitigation plan is in compliance with Idaho law. (3-31-22)
b. Whether the mitigation plan will provide replacement water, at the time and place required by the senior-priority water right, sufficient to offset the depletive effect of ground water withdrawal on the water available in the surface or ground water source at such time and place as necessary to satisfy the rights of diversion from the surface or ground water source. Consideration will be given to the history and seasonal availability of water for diversion so as not to require replacement water at times when the surface right historically has not received a full supply, such as during annual low-flow periods and extended drought periods. (3-31-22)
c. Whether the mitigation plan provides replacement water supplies or other appropriate compensation to the senior-priority water right when needed during a time of shortage even if the effect of pumping is spread over many years and will continue for years after pumping is curtailed. A mitigation plan may allow for multi-season accounting of ground water withdrawals and provide for replacement water to take advantage of variability in seasonal water supply. The mitigation plan must include contingency provisions to assure protection of the senior-priority right in the event the mitigation water source becomes unavailable. (3-31-22)
d. Whether the mitigation plan proposes artificial recharge of an area of common ground water supply as a means of protecting ground water pumping levels, compensating senior-priority water rights, or providing aquifer storage for exchange or other purposes related to the mitigation plan. (3-31-22)
e. Where a mitigation plan is based upon computer simulations and calculations, whether such plan uses generally accepted and appropriate engineering and hydrogeologic formulae for calculating the depletive effect of the ground water withdrawal. (3-31-22)
f. Whether the mitigation plan uses generally accepted and appropriate values for aquifer characteristics such as transmissivity, specific yield, and other relevant factors. (3-31-22)
g. Whether the mitigation plan reasonably calculates the consumptive use component of ground water diversion and use. (3-31-22)
h. The reliability of the source of replacement water over the term in which it is proposed to be used under the mitigation plan. (3-31-22)
i. Whether the mitigation plan proposes enlargement of the rate of diversion, seasonal quantity or time of diversion under any water right being proposed for use in the mitigation plan. (3-31-22)
j. Whether the mitigation plan is consistent with the conservation of water resources, the public interest or injures other water rights, or would result in the diversion and use of ground water at a rate beyond the reasonably anticipated average rate of future natural recharge. (3-31-22)
k. Whether the mitigation plan provides for monitoring and adjustment as necessary to protect senior-priority water rights from material injury. (3-31-22)
l. Whether the plan provides for mitigation of the effects of pumping of existing wells and the effects of pumping of any new wells which may be proposed to take water from the areas of common ground water supply. (3-31-22)
m. Whether the mitigation plan provides for future participation on an equitable basis by ground water pumpers who divert water under junior-priority rights but who do not initially participate in such mitigation plan. (3-31-22)
n. A mitigation plan may propose division of the area of common ground water supply into zones or segments for the purpose of consideration of local impacts, timing of depletions, and replacement supplies. (3-31-22)
o. Whether the petitioners and respondents have entered into an agreement on an acceptable mitigation plan even though such plan may not otherwise be fully in compliance with these provisions. (3-31-22)
044. -- 049. (RESERVED)
01. Eastern Snake Plain Aquifer. The area of coverage of this rule is the aquifer underlying the Eastern Snake River Plain as defined in Section 42-233c, Idaho Code. (7-1-25)
051. -- 999. (RESERVED)