(1) Final water court approved stipulations, master's reports, or examination information related to the water right being changed must be submitted with the application, however, this information or an abstract of a water right from the department or the Montana water court by itself is not sufficient to prove the existence or extent of the historical use.

(2) The amount of water being changed for each water right cannot exceed or increase the flow rate historically diverted under the historic use, nor exceed or increase the historic volume consumptively used under the existing use.

(3) An applicant shall compare historical acres irrigated to acres identified as irrigated in the Water RESOURCES Survey, if available for the place of use. If the Water RESOURCES Survey does not support the historical irrigation alleged in the application, the applicant shall explain why. Information from irrigation journals or logs or old aerial photographs can be submitted for consideration.

(4) If an applicant provides a "best available estimate" to any element or requirement in (5) through (7) , an explanation of how the estimate was derived must be included. For example, best available estimates might be based on the following:

(a) aerial photographs depicting irrigated land;

(b) aerial or other photographs showing diversion or conveyance structures;

(c) Water RESOURCES Survey book information;

(d) Water RESOURCES Survey field notes;

(e) water commissioner field notes;

(f) natural RESOURCES conservation service information;

(g) affidavits from persons with first-hand knowledge of historic use;

(h) calculation of historic ditch capacities;

(i) log books or diaries of previous irrigators; or

(j)other information that provides independent corroboration of the historic use that allows reasonable estimates of historic diversion and historic consumption.

(5) The applicant shall provide a narrative of the historic use of each water right being changed. The description must be based on actual physical measurements when available and use commonly accepted hydraulic principles. The narrative must contain the following:

(a) the maximum flow rate diverted from each point of diversion listed on the water right during the period of diversion;

(b) total volume of water consumed for each water right during the period of diversion;

(c) a description of how and when unconsumed water returns to a ground or surface water source and how that return flow volume was calculated; and

(d) documentation of the basis of all data used in the analysis, methods of analysis and calculations.

(6) The applicant shall provide written documentation explaining the historic use and how the information was acquired to substantiate the following elements of each water right proposed to be changed:

(a) point of diversion;

(b) period of diversion;

(c) volume used for each purpose;

(d) period of use for each purpose;

(e) place of use for each purpose;

(f) maximum number of acres historically irrigated;

(g) means of conveyance;

(h) location of reservoir;

(i) maximum volume in acre-feet of water stored;

(j) maximum number of times a reservoir was filled during a year; and

(k) maximum period of time when water was collected for storage.

(7) A narrative must be included in the application materials explaining the historic operation of the right, including flow rate, volume, period of diversion, period of use, and period of storage are reasonable and typical of the purpose for which the historic right was used.