Okla. Stat. tit. 82 § 638
Whenever the owners, or representatives of twenty-five percent (25%) or more of the acreage or value of the lands in the district shall file a petition with the court clerk in whose office the petition was filed, stating that there has been a material change in the value of the property in the district since the last previous appraisal of benefits, and praying for a readjustment of the appraisal of benefits for the purpose of making equitable basis for the levy of the maintenance assessment, the said clerk shall give notice of the filing and hearing of said petition in the manner hereinbefore provided.
Upon hearing said petition if said court shall find there has been a material change in the value of property in said district since the last previous appraisal of benefits, the court shall order that there be a readjustment of the appraisal benefits for the purpose of providing a basis upon which to levy the maintenance assessment of said district. Thereupon the court shall direct the appraisers of the conservancy district to make such readjustment of appraisal in the manner provided in this act, and said appraisers shall make their report; and the same proceedings shall be had thereon, as nearly as may be, as are herein provided for the appraisal of benefits accruing for original construction. Provided, that in making the readjustment of the appraisal of benefits said appraisals shall not be limited to the aggregate amount of the original or any previous appraisal benefits, and that after the making of such readjustment of limitations of such annual maintenance assessment to one percent (1%) of the total appraised benefits shall apply to the amount of the benefits as readjusted; and provided, further, that there shall be no such readjustment of benefits oftener than once in ten (10) years.
Okla. Stat. tit. 82, § 638