Okla. Const. art. XVI, § 3

System of levees, drains, and ditches and irrigation. The Legislature shall have power and shall provide for a system of levees, drains, and ditches and of irrigation in this State when deemed expedient, and provide for a system of taxation on the lands affected or benefited by such levees, drains, and ditches and irrigation, or on crops produced on such land, to discharge such bonded indebtedness or expenses necessarily incurred in the establishment of such improvements; and to provide for compulsory issuance of bonds by the owners or lessees of the lands benefited or affected by such levees, drains, and ditches or irrigation.