Neb. Rev. Stat. §§ 23-308
Whenever any portion of a county exceeding three hundred and twenty acres in amount is put in peril of destruction by reason of the probable diversion of the channel of any river or watercourse, and whenever a petition stating such fact, signed by twenty freeholders in the precinct, is filed with the county board of such county, it shall be the duty of the county board to view said premises within the succeeding thirty days, and if upon actual view it shall appear that a portion of the county exceeding three hundred and twenty acres is in actual peril of destruction, it may cause to be built any dam, embankment or dike, or aid to such an extent as it may deem proper in the building of any dam, embankment or dike that it may deem necessary for the protection of said land. The amount expended toward such improvements shall be paid out of the general fund of the county.
Neb. Rev. Stat. §§ 23-308