Okla. Stat. tit. 82 § 666
Any territory in which a proceeding has been instituted or is pending for construction of a single or joint or interstate, or county ditch, or township ditch, or underground drain, or levee, or county sewer, or for the cleaning of drains and water courses, or for the removal of drifts, or for the drainage of marshes; or for any sewer district outside of a municipality, or organized under any other law of this state, may become a district or subdistrict under this act, or may be absorbed in and amalgamated with any district organized under the terms of this act in the following manner:
When the officials in charge of any such improvement, or in the board of directors of any district organized under this act, which may desire to annex or absorb such territory, petition the court in which such district was organized under this act, or the court having jurisdiction over all or part of the territory affected by the proceedings which is desired to bring under this act, for an order making the territory affected by any of the improvements above noted a district or subdistrict under the terms of this act, or for amalgamating such territory with an existing district, organized under the terms of this act, the court clerk shall give notice of the pendency of said petition and of a hearing thereon in the same manner as herein provided for notice and hearing on a petition for the organization of a district under this act. At the time of such hearing the court shall hear the evidence and shall grant the petition or deny the same, as seems most advantageous to all the interests affected thereby.
The court, in its order shall specify whether such territory shall be organized into a district or subdistrict under the terms of this act, or whether it shall be absorbed in or amalgamated with an existing district, organized under this act. Thereafter the territory affected by said order and the improvements for which said territory was assessed, or for which contracts have been let therein, shall be subject to the terms of this act, and all such orders and procedure shall be had, as are necessary for fulfilling the requirements of this act; provided, that no order of the court shall be made under this section, which shall lessen the security of any issue of bonds or other obligations issued under the terms of this or any other statute.
If a proceeding sought to be joined to or amalgamated with a proceeding under this act is under the jurisdiction of a district court other than the one having jurisdiction of the district organized under this act, then at such hearing the district judge or judges of the county or counties in which such ditch or other improvements is located shall sit with the judge in whose county the district was established under this act, and a majority of those sitting shall be necessary to a decision; and from such decision or from a failure to decide appeal may be taken.
Okla. Stat. tit. 82, § 666