Okla. Stat. tit. 69 § 1318
The governing body of the city or the board of county commissioners at such session, or at any adjournment thereof, shall have the power to review, modify or correct the appraisement and apportionment, and to raise or lower the same as to any lots or parcels of land, as it shall deem just, and shall, by resolution, confirm the same as so revised and corrected. At such session any party interested may file objections in writing against the validity or amount of any proposed assessment and shall have full opportunity to be heard thereon; and any objections to the regularity of the proceedings with reference to the construction of the improvements or the validity or the amount of the assessment shall be waived unless presented at the time and in the manner herein specified.
Okla. Stat. tit. 69, § 1318