In its discretion, either upon its own initiative or in response to a specific request, the office, subject to the approval of the Kansas water authority, may include in the state water plan recommendations for the inclusion at state expense of any conservation storage features for water supply in any proposed or authorized or constructed water development project of the federal government of any conservation storage features for water supply that in the opinion of the office will be needed within the state in the future to achieve the purposes of this act. Before making such recommendations the office shall find that (1) such recommended features are consistent with the state water plan; (2) the recommended features will achieve or tend to achieve the purposes of this act; (3) the federal government will not at its expense include those features for the purposes contemplated by the office under terms which would assure essential state control of the waters of the state or meeting of state objectives, which purposes may include maintenance and operational requirements in the use thereof that the office shall specify for achievement of the purposes of this act; and (4) in the future some responsible person or persons will have needs for the use of all or a portion of the recommended conservation storage and that such person or persons will request the use thereof within a period of time which will permit them to pay out their proportionate share of the costs allocated to such needs within the life of the project.