Concept Design Option 2: Nearshore Reefs

A nearshore reef slows down waves as they approach the shoreline and provides space for fish and other aquatic life to use as habitat.

This option is similar to the offshore breakwater, however there are some key differences.

  • all of the stone is located below the high water level, meaning it is generally not visible from above water
  • it is generally much wider to account for its lower height
  • stone used is much smaller

Key Benefits

Built along the shoreline into nearshore

Simultaneously provide wave protection and aquatic habitat

Nearshore Reef Cross-section. W.F. Baird, 2022

 

Advantages

  • No visual impact to shoreline once completed
  • It can provide aquatic habitat by reducing velocities in the nearshore
  • Failures are likely to be gradual, allowing opportunities for minor maintenance
  • Smaller rip rap is more available and less costly

 

Disadvantages

  • Large amount of in-water work and disturbance
  • Impacts to navigation from submerged structures
  • Large amounts of material to be delivered and installed on site
  • Less effective than other methods at high water levels due to the submerged height of the structure.

This option is currently not the most preferred for any reach, but it is recommended for Reach 1 and Reach 10. It has a rough costing of $27,000/m.