25 U.S. Code § 564l - Klamath irrigation works
That part of section 499 of title 43, which relates to the transfer of the care, operation, and maintenance of reclamation works to water users associations or irrigation districts shall be applicable to the irrigation works on the Klamath Reservation.
Effective on the first day of the calendar year beginning after the date of the proclamation provided for in section 564q of this title, the deferment of the assessment and collection of construction costs provided for in the first proviso of section 386a of this title, shall terminate with respect to any lands within irrigation projects on the Klamath Reservation. The Secretary shall cause the first lien against such lands created by section 387  of this title, to be filed of record in the appropriate county office.
There is authorized to be appropriated out of any funds in the Treasury not otherwise appropriated the sum of $89,212 for payment to the Klamath Tribe with interest at 4 per centum annually as reimbursement for tribal funds used for irrigation construction operation and maintenance benefiting nontribal lands on the Klamath Reservation, such interest being computed from the dates of disbursement of such funds from the United States Treasury.
The Secretary is authorized to adjust, eliminate, or cancel all or any part of reimbursable irrigation operation and maintenance costs and reimbursable irrigation construction costs chargeable against Indian owned lands that are subject to the provisions of this subchapter, and all or any part of assessments heretofore or hereafter imposed on account of such costs, when he determines that the collection thereof would be inequitable or would result in undue hardship on the Indian owner of the land, or that the administrative costs of collection would probably equal or exceed the amount collected.
Nothing contained in any other section of this subchapter shall affect in any way the laws applicable to irrigation projects on the Klamath Reservation.
 See References in Text note below.