Okla. Stat. tit. 82 § 639
The board of directors shall each year thereafter determine, order and levy the part of the local assessment levied under this act, which shall become due and collectable during each year at the same time the state and county taxes are due and collected, which annual levy shall be evidenced and certified by said board not later than October first of each year to the county clerk of each county in which the real or other property affected by said district is situated. The certificate of said annual levy shall be substantially as in the schedule herein.
They shall follow a table or schedule showing in properly ruled columns:
The said certificates and report shall be prepared in triplicate in a well-bound book which shall be endorsed and named "Conservancy Assessment Book of .............. District ...... County, Oklahoma", which endorsement shall also be printed at the top of each page in said book.
Two copies of that part of such triplicate affecting lands in any county shall be forwarded to the county clerk of such county, one for his use and one for the county treasurer, to whom the clerk shall certify one copy. It shall be the duty of the county clerk of each county to receive the same as a special assessment book, and to certify the same as other special assessment records to the county treasurer of his county, whose duty it shall be to collect the same according to law. And such special assessment book shall be the treasurer's warrant and authority to demand and receive the assessment due in his county as found in the same, and it shall be unlawful for any such county treasurer to accept payment of the general taxes levied against any tract, parcel, piece of land or property described in such conservancy assessment book, until the owner has been notified by him that there is a special assessment noted in the conservancy book against such tract of land or other property.
Okla. Stat. tit. 82, § 639