Authorizes any landholder in Oregon within the Rogue River Valley Irrigation District or the Medford Irrigation District to repay, at any time, the construction costs of the project facilities allocated to a landholding within such district. Provides that, upon discharge of the repayment obligation, the lands at issue shall not be subject to ownership and full-cost pricing limitations under reclamation and irrigation provisions. Directs the Secretary of the Interior, upon request, to provide certification of the landholder's freedom from such limitations.