REMOVAL OF PRATTE'S REEF - A MAN-MADE SURF ENHANCEMENT STRUCTURE

Client: Surfrider Foundation

In September 2000, the Surfrider Foundation installed an experimental surfing reef off Dockweiler State Beach in El Segundo, California. The structure, known as Pratte’s Reef, was constructed of sand-filled geotextile bags placed in a V-shaped configuration. The project objective was to mitigate the impacts on recreational surfing caused by the construction of a shore-perpendicular groin.

When Coastal Frontiers personnel inspected the reef in 2008, significant deterioration of the geotextile bags was noted, raising the possibility of fabric discharge into the marine environment. This finding, coupled with the reef's failure to produce a sustained enhancement in surf quality, prompted the Surfrider Foundation to initiate the first phase of a reef removal program in fall 2008. The second and final phase was conducted in 2010.

Based on extensive past experience with the decommissioning of geotextile armor systems in the Arctic Ocean, Coastal Frontiers was engaged to perform the following tasks for the first-ever removal of a man-made surfing reef:

Geotextile Bag Removal

Reef Removal Tasks

  • Develop strategies for both vessel-based and land-based removal of 14-ton sand bags

  • Obtain all necessary permits from Federal, state, and local regulatory agencies

  • Map the reef outline prior to the initiation of removal activities

  • Provide on-site guidance for the professional dive crew, shore crew, and support vessel

  • Compile a list of lessons learned applicable to the removal of man-made surf enhancement structures

Key Findings

  • The efficiency of the removal effort is extremely sensitive to the prevailing wave and water level conditions

  • The cost of removing a geotextile-based nearshore structure can equal or exceed the cost of installation