In cases where the use of water for irrigation is necessary to render the lands within any Indian reservation available for agricultural purposes, the Secretary of the Interior is authorized to prescribe such rules and regulations as he may deem necessary to secure a just and equal distribution thereof among the Indians residing upon any such reservations; and no other appropriation or grant of water by any riparian proprietor shall be authorized or permitted to the damage of any other riparian proprietor.

In carrying out any irrigation project which may be undertaken under the provisions of the Act of June seventeenth, nineteen hundred and two (Thirty-second Statutes, page three hundred and eighty-eight), known as “The Reclamation Act,” and which may make possible, and provide for in connection with the reclamation of other lands, the irrigation of all or any part of the irrigable lands heretofore included in allotments made to Indians under section 334 of this title, the Secretary of the Interior is authorized to make such arrangement and agreement in reference thereto as said Secretary deems for the best interest of the Indians: Provided, That no lien or charge for construction, operation, or maintenance shall thereby be created against any such lands.

The Commissioner of Indian Affairs, under the direction of the Secretary of the Interior, may employ superintendents of irrigation who shall be skilled irrigation engineers, not to exceed seven in number.

For lands irrigable under any irrigation system or reclamation project the Secretary of the Interior may fix maintenance charges which shall be paid as he may direct, such payments to be available for use in maintaining the project or system for which collected: Provided further, That all moneys expended under this provision shall be reimbursable where the Indians have adequate funds to repay the Government, such reimbursements to be made under such rules and regulations as the Secretary of the Interior may prescribe: Provided further, That the Secretary of the Interior is authorized and directed to apportion the cost of any irrigation project constructed for Indians and made reimbursable out of tribal funds of said Indians in accordance with the benefits received by each individual Indian so far as practicable from said irrigation project, said cost to be apportioned against such individual Indian under such rules, regulations, and conditions as the Secretary of the Interior may prescribe.

Effective August 7, 1946, collections made from water users on each Indian irrigation project on account of assessments levied to meet the cost of operating and maintaining such project shall be deposited into the Treasury for credit to a trust-fund account pursuant to section 1321 of title 31, and shall be available for expenditure in carrying out the purposes for which collected.

There shall be credited to each trust-fund account established under section 385a of this title the excess, if any, of (1) the unexpended balance of any repealed special fund appropriation to which operation and maintenance collections were credited prior to July 1, 1935

Revenues collected after August 7, 1946, from power operations on each Indian irrigation project and deposited into the Treasury for credit to miscellaneous receipts pursuant to section 4 of the Permanent Appropriation Repeal Act, 1934 (48 Stat. 1227), or pursuant to other provisions of law, are authorized to be appropriated annually, in specific or in indefinite amounts, equal to the collections so credited, for the following purposes in connection with the respective projects from which such revenues are derived: (1) Payment of the expenses of operating and maintaining the power system; (2) creation and maintenance of reserve funds to be available for making repairs and replacements to, defraying emergency expenses for, and insuring continuous operation of the power system, the fund for each project to be maintained at such level, within limits set by the Director of the Office of Management and Budget, as may from time to time be prescribed by the Secretary of the Interior; (3) amortization, in accordance with the repayment provisions of the applicable statutes or contracts, of construction costs allocated to be returned from power revenues; and (4) payment of other expenses and obligations chargeable to power revenues to the extent required or permitted by law.

The Secretary of the Interior is authorized and directed to require the owners of irrigable land under any irrigation system constructed for the benefit of Indians and to which water for irrigation purposes can be delivered to begin partial reimbursement of the construction charges, where reimbursement is required by law, at such times and in such amounts as he may deem best; all payments hereunder to be credited on a per acre basis in favor of the land in behalf of which such payments shall have been made and to be deducted from the total per acre charge assessable against said land.

The Secretary of the Interior is hereby authorized and directed to adjust or eliminate reimbursable charges of the Government of the United States existing as debts against individual Indians or tribes of Indians in such a way as shall be equitable and just in consideration of all the circumstances under which such charges were made: Provided, That the collection of all construction costs against any Indian-owned lands within any Government irrigation project is hereby deferred, and no assessments shall be made on behalf of such charges against such lands until the Indian title thereto shall have been extinguished, and any construction assessments heretofore levied against such lands in accordance with the provisions of section 386 of this title, and uncollected, are hereby canceled: Provided further, That the Secretary shall report such adjustments and eliminations to the Congress not later than sixty calendar days following the end of the fiscal year in which they are made: Provided further, That any proceedings hereunder shall not be effective until approved by Congress unless Congress shall have failed to act favorably or unfavorably thereon by concurrent resolution within ninety calendar days after the filing of said report, in which case they shall become effective at the termination of the said ninety calendar days: Provided further, That the Secretary shall adjust or eliminate charges, defer collection of construction costs, and make no assessment on behalf of such charges for beneficiaries that hold leases on Hawaiian home lands, to the same extent as is permitted for individual Indians or tribes of Indians under this section.

The Secretary of the Interior is authorized to pay out of funds available for the Indian irrigation projects for damages caused to owners of lands or other private property of any kind by reason of the operations of the United States, its officers or employees, in the survey, construction, operation, or maintenance of irrigation works of such projects and which may be compromised by agreement between the claimant and the Secretary of the Interior or such officers as he may designate: Provided, That the total of any such claims authorized to be settled as herein contemplated shall not exceed 5 per centum of the funds available for the project under which such claims arise during any one fiscal year.

The Secretary of the Interior is authorized and directed to cause an investigation to be made to determine whether the owners of non-Indian lands under Indian irrigation projects and under projects where the United States has purchased water rights for Indians are unable to pay irrigation charges, including construction, maintenance, and operating charges, because of inability to operate such lands profitably by reason of lack of fertility of the soil, inadequacy of water supply, defects of irrigation works, or for any other causes. Where the Secretary finds that said landowners are unable to make payment due to the existence of such causes, he may adjust, defer, or cancel such charges, in whole or in part, as the facts and conditions warrant. In adjusting or deferring any such charges the Secretary may enter into contracts with said land owners for the payment of past due charges, but such contracts shall not extend the payment of such charges over a period in excess of ten years.

Where the Secretary finds that any such lands cannot be cultivated profitably due to a present lack of water supply, proper drainage facilities, or need of additional construction work, he shall declare such lands temporarily nonirrigable for periods not to exceed five years and no charges shall be assessed against such lands during such periods.

Where the Secretary finds that any such lands are permanently nonirrigable he may, with the consent of the landowner, eliminate such lands from the project.

Where irrigation assessments against any such lands remained unpaid at the time the Indian title to such lands became extinguished and no lien existed and attached to such lands for the payment of charges so assessed and no contract for the payment of such charges was entered into, the Secretary shall cancel all such charges.

The Secretary shall have power to make such rules and regulations as may be necessary to carry out the provisions of sections 389 to 389e of this title.

The Secretary shall include in the report to Congress required pursuant to section 389a 1

The Secretary of the Interior be, and he is hereby, authorized, in his discretion, to grant concessions on reservoir sites, reserves for canals or flowage areas, and other lands under his jurisdiction which have been withdrawn or otherwise acquired in connection with the San Carlos, Fort Hall, Flathead, and Duck Valley or Western Shoshone irrigation projects for the benefit in whole or in part of Indians, and to lease such lands for agricultural, grazing, or other purposes: Provided, That no lands so leased shall be eligible for benefit payments under the crop control program, or the soil conservation act: Provided further, That such concessions may be granted or lands leased by the Secretary of the Interior under such rules, regulations, and laws as govern his administration of the public domain as far as applicable, for such considerations, monetary or otherwise, and for such periods of time as he may deem proper, the term of no concession to exceed a period of ten years: Provided further