Wave Barrier: Flood Adaptation Measure


South Beach Harbor wave barrier ©Civic Edge Consulting

PHYSICAL INFRASTRUCTURE
SHORELINE LOCATION: In Water



DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
50 - 100+ Years
Low
Living with Water
TBD


COASTAL FLOOD HAZARDS MITIGATED:
Sea Level Rise
Storm Surge
Groundwater
Waves
Erosion


MEASURES COMPATABILITY
ECOSYSTEM SERVICES: Measure may affect these shoreline values
Flood
Seismic
All
All
Aquatic Habitat
Terrestrial Habitat
Water Quality
Carbon Storage


DESCRIPTION:
Wave barriers are in common use around the San Francisco Bay for reducing wave energy in marinas or in some cases recreational or habitat areas. These structures extend above the waters surface at all tide levels and can be built of sheet piles or rubble mounds. Sheet Piles take up less space in the water and are typically supported by piles driven into the ground. Rubble mound wave barriers sit on the underwater surface, and beacuse of their sloping sides have a larger footprint than sheet pile wave barriers.


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • Offshore construction presents a number of challenges with feasibility, cost, and impact.
  • Reduces wave energy on the sheltered side of the structure reducing wave runup and overtopping.
  • Can sustain damage or adjust to settlement without catastrophic failure.
  • Rubble mound waver barrier can provide habitat for rock-dwelling flora and fauna, and fish.
  • Expensive in deep water.
  • Emergent structures can be unsightly.
  • Can interfere with ship traffic.
  • High wave reflection off the bay side of the structure, particularly for designs with solid walls.
  • Relatively costly due to offshore construction costs.


CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
CASE STUDIES:
  • Minimal impact to waterfront uses as construction occurs in the water.
  • Design height should consider extreme events and future sea level rise. After construction, modifications to extend the height of the structure would be costly.
  • None cited


DESIGN OPPORTUNITIES:
Ecological Enhancements
Urban Design
Form
  • Rubble mound barriers can be constructed to provide aquatic habitat by providing surfaces to promote growth of mollusks and aquatic vegetation
  • N/A
  • N/A


DESIGN CONSIDERATIONS:

  • Must be designed to resist lateral wave loads.
  • Appropriate materials should be selected for use in the marine environment.
  • Could affect sediment transport patterns and surrounding shorelines.

SITE-SPECIFIC CONSIDERATIONS:

  • Water levels, waves, currents and propeller wash from ship activity should be well defined.
  • Geotechnical investigations should be performed to determine bottom characteristics, potential for settlement, and global stability failure.
  • Sub-bottom profiling should be performed to identify buried debris or other features that could limit pile drivability.
  • Sufficient water depth should be available to prevent the attenuators from bottoming out during low tides.
  • Impacts to maritime uses should be considered in siting and design.

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • Offshore construction would be performed from a barge by a competent marine contractor.
  • Noise issues with pile driving for sheet pile version have could impact aquatic and terrestrial wildlife as well as people near the site.
  • Stone used for rubble mound structures would be delivered to the site either by truck or by barge.
  • A relatively large staging area would be required for the quantities of stone required by the structure.
  • Although the rubble mound structure would create habitat for marine life that would colonize the hard surfaces and voids, it would also cover a significant amount of seabed habitat.

HISTORICAL RESOURCE CONSIDERATIONS:

  • In-Bay construction would need to consider potential buried archeological resources.


Download the Wave Barrier Factsheet.

Learn about other types of measures from our Measures Explorer page.


South Beach Harbor wave barrier ©Civic Edge Consulting

PHYSICAL INFRASTRUCTURE
SHORELINE LOCATION: In Water



DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
50 - 100+ Years
Low
Living with Water
TBD


COASTAL FLOOD HAZARDS MITIGATED:
Sea Level Rise
Storm Surge
Groundwater
Waves
Erosion


MEASURES COMPATABILITY
ECOSYSTEM SERVICES: Measure may affect these shoreline values
Flood
Seismic
All
All
Aquatic Habitat
Terrestrial Habitat
Water Quality
Carbon Storage


DESCRIPTION:
Wave barriers are in common use around the San Francisco Bay for reducing wave energy in marinas or in some cases recreational or habitat areas. These structures extend above the waters surface at all tide levels and can be built of sheet piles or rubble mounds. Sheet Piles take up less space in the water and are typically supported by piles driven into the ground. Rubble mound wave barriers sit on the underwater surface, and beacuse of their sloping sides have a larger footprint than sheet pile wave barriers.


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • Offshore construction presents a number of challenges with feasibility, cost, and impact.
  • Reduces wave energy on the sheltered side of the structure reducing wave runup and overtopping.
  • Can sustain damage or adjust to settlement without catastrophic failure.
  • Rubble mound waver barrier can provide habitat for rock-dwelling flora and fauna, and fish.
  • Expensive in deep water.
  • Emergent structures can be unsightly.
  • Can interfere with ship traffic.
  • High wave reflection off the bay side of the structure, particularly for designs with solid walls.
  • Relatively costly due to offshore construction costs.


CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
CASE STUDIES:
  • Minimal impact to waterfront uses as construction occurs in the water.
  • Design height should consider extreme events and future sea level rise. After construction, modifications to extend the height of the structure would be costly.
  • None cited


DESIGN OPPORTUNITIES:
Ecological Enhancements
Urban Design
Form
  • Rubble mound barriers can be constructed to provide aquatic habitat by providing surfaces to promote growth of mollusks and aquatic vegetation
  • N/A
  • N/A


DESIGN CONSIDERATIONS:

  • Must be designed to resist lateral wave loads.
  • Appropriate materials should be selected for use in the marine environment.
  • Could affect sediment transport patterns and surrounding shorelines.

SITE-SPECIFIC CONSIDERATIONS:

  • Water levels, waves, currents and propeller wash from ship activity should be well defined.
  • Geotechnical investigations should be performed to determine bottom characteristics, potential for settlement, and global stability failure.
  • Sub-bottom profiling should be performed to identify buried debris or other features that could limit pile drivability.
  • Sufficient water depth should be available to prevent the attenuators from bottoming out during low tides.
  • Impacts to maritime uses should be considered in siting and design.

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • Offshore construction would be performed from a barge by a competent marine contractor.
  • Noise issues with pile driving for sheet pile version have could impact aquatic and terrestrial wildlife as well as people near the site.
  • Stone used for rubble mound structures would be delivered to the site either by truck or by barge.
  • A relatively large staging area would be required for the quantities of stone required by the structure.
  • Although the rubble mound structure would create habitat for marine life that would colonize the hard surfaces and voids, it would also cover a significant amount of seabed habitat.

HISTORICAL RESOURCE CONSIDERATIONS:

  • In-Bay construction would need to consider potential buried archeological resources.


Download the Wave Barrier Factsheet.

Learn about other types of measures from our Measures Explorer page.