Okla. Stat. tit. 11, § 11-36-216

Assessments in conformity to the appraisement and apportionment,

as corrected and confirmed by the governing body, shall be payable

in ten equal annual installments, and shall bear interest at the

rate of not to exceed thirteen percent (13%) per annum until paid,

payable in each year at such time as the several installments are

made payable. The governing body, by ordinance and by referring to

the assessment roll as confirmed, shall levy assessments in

accordance with the assessment roll as confirmed against the several

lots and tracts of land liable therefor. The ordinance shall

provide that the owners of the property so assessed shall have the

privilege of paying the amounts of their respective assessments

without interest within thirty (30) days after the date of the

publication of the assessing ordinance. The special assessments,

and each installment thereof and the interest thereon, are hereby

declared to be a lien against the lots and tracts of land so

assessed from the date of the publication of the ordinance levying

the same, coequal with the lien of other taxes and prior and

superior to all other liens against such lots or tracts of land. The

lien shall continue as to unpaid installments and interest until the

assessments and interest thereon shall be fully paid, but unmatured

installments shall not be deemed to be within the terms of any

general convenant or warranty.