R655-13-4. Definitions

  (1) Alteration: To obstruct, diminish, enhance, destroy, alter, modify, relocate, realign, change, or potentially affect the existing condition or shape of a channel, or to change the path or characteristics of water flow within a natural channel. It includes processes and results of removal or placement of material or structures within the jurisdiction delineated in this rule.

  (2) Bankfull discharge: The flow corresponding to the elevation of the water surface, in a natural stream, where overflowing onto the floodplain normally begins. Bankfull discharge is considered analogous to ordinary high water or average seasonal high flow. In urbanized streams this is often lower than the top of bank.

  (3) Bank(s): The confining sides of a natural stream channel, including the adjacent complex that provides stability, erosion resistance, aquatic habitat, or flood capacity.

  (4) Bed: The bottom of a natural stream channel.

  (5) Channel: The bed and banks of a natural stream.

  (6) Clearance: The vertical distance between a given water surface and the lowest point on any structure crossing a natural channel.

  (7) Ecosystem: The assemblage of organisms and their environment functioning as an ecological unit in nature.

  (8) Floodplain: The maximum area that will accommodate water when flow exceeds bankfull discharge.

  (9) Flowline: The lowest part of a bed when viewed in cross-section.

  (10) Fluvial: 1: Of, relating to, or living in a stream or river. 2: Produced by stream action.

  (11) Natural stream: Any waterway, along with its fluvial system, that receives sufficient water to sustain an ecosystem that distinguishes it from the surrounding upland environment.

  (12) State Engineer: Director of the Division of Water Rights.

  (13) Waterway: A topographic low that collects and conveys water.