455 Neb. Admin. Code, ch. 1, § 003
When adequate flood elevation and other necessary data and information are available from federal, state, or other sources, the entity responsible for assuring compliance with the rules and regulations in this Chapter shall, before permitting the location of an obstruction or substantial improvement in the floodplain of a base flood, determine whether the proposed obstruction is located in the flood fringe or in a floodway. Normally, the floodway shall be determined using the method requiring equal loss of conveyance on opposite sides of the stream. If the equal loss of conveyance method is not technically appropriate in a specific situation, the responsible entity may select and utilize another more appropriate method which is acceptable in accordance with hydraulic engineering principles and standards.
455 Neb. Admin. Code, ch. 1, § 003