Okla. Stat. tit. 82, § 1324.42

No person shall make an offer for, or enter into any agreement to exchange, seek to acquire, or acquire, the assets of a district or corporation if, after the consummation of such action, such person would directly or indirectly, or by conversion or by exercise of any right to acquire, be in control of such district or corporation, and no person shall merge with or otherwise acquire control of a district or corporation, unless, at the time any such offer, request or invitation is made or prior to the acquisition of assets, such person has sent to the Oklahoma Water Resources Board a statement containing the information required by Section 7 of this act and such offer, request, invitation, or acquisition has been approved by the Board in the manner prescribed by Section 8 of this act.