GABIONS, PERFORATED PIPE AND GRAVEL SERVE AS FISH SCREENS

This system to prevent the migration of young salmon to the sea consists of perforated pipe, gabions, gravel and cobbles, a steel slide gate and a headwall. The gabions which are made of heavy triple twisted wire are shipped flat and are opened, filled with 6 in. minimum size cobbles, and tied on the job site. Incorporated with perforated steel pipe, a metal slide gate with concrete headwall, and emergency flow weir box, and natural stream gravel and cobbles, they are being used in 6 different division structures. A gobion dam is constructed as near the canal head as is practical. Perforated pipe (36 in.) encased or sorrounded by river run gravel is placed through the dam and extended upstream in the river bed at an elevation where it can be covered with about 7 in. of gravel. Thus all the water to the canal comes through the gravel pipe perforations and the gabion dam. As an emergency water supply feature, a weir box with removable flash boards is installed in the dam should the gravel, perforations or dam interstrices clog. A few feet downstream, a metal slide gate on a concrete headwall is provided for positive flow regulation.

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Filing Info

  • Accession Number: 00139828
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 6 1976 12:00AM