Neb. Rev. Stat. § 46-234

If there is no unappropriated water in the source of supply or if a prior appropriation has been perfected to water the same land to be watered by the applicant, the Chief Water Officer may refuse such application. An application may also be refused (1) if existing facilities other than those owned or operated by the applicant are to be utilized and the applicant fails to show, by documentary evidence, agreements with the owner and operator of the facilities to allow the applicant to use such facilities or (2) when denial is demanded by the public interest. The party making such application shall not prosecute such work so long as such refusal continues in force. An application for appropriation shall not be exclusive of any of the lands included therein until the owner or owners of such land give consent to the same in proper form duly acknowledged. No application made or canal constructed, prior to the application of the water and the perfection of an appropriation therefor or the filing of the consent, shall prevent other applications from being allowed and other canals from being constructed to irrigate the same lands or any of them. In case of an application for an appropriation of water for the development of water power, the Chief Water Officer shall promptly act upon such application and limit the time within which such appropriation shall be perfected to the period within which the proposed power project can be completed by uninterrupted and expeditious construction.