NMFS-CV-BO-IWW-04

Relief Culverts or Structures

For relief culverts or structures, if a pipe or structure that empties flow from a non-fish bearing stream is installed, an energy dissipater shall be installed to reduce bed and bank scour. This does not apply to culverts or structures conveying flow that may be considered part of a fish-bearing stream. Any such structures shall comply with NMFS fish passage guidelines. The toe of rock slope protection used for streambank stabilization shall be placed sufficiently below the bed scour depth to ensure stability.