Mechanical and Bouyant Gates: Flood Adaptation Measure




NEED TO UPDATE

PHYSICAL INFRASTRUCTURE
SHORELINE LOCATION:
Shoreline or Asset Specific




DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
15 - 25+ years
Low
Minor Intervention
TBD


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


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


DESCRIPTION:
Mechanical and bouyant gates can provide permanent flood protection while still allowing access to the resources they protect. They are typically constructed with a steel gate, and a reinforced concrete foundation. They can also be fabricated in stainless steel and aluminum, making for lighter options than the equivalent steel gates. They are permanent in the sense that their foundation and location is permanent, but they are deployed (closed) only in storm and flood events. Gates are a proven concept and are reliable with adequate inspection and maintenance


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • NEED TO UPDATE
  • No installation or construction required during flood event.
  • Easy and quick operation.
  • No off-site storage or transportation required.
  • Stable and strong, with high resistance to impact.
  • Height cannot be increased during surface.
  • Possibility of failure of mechanical part of electricity supply (if automatic).
  • Structure could get jammed with debris.
  • Limited applicability at landscape scale.


CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
CASE STUDIES:
  • N/A
  • Not adaptable
  • None cited


DESIGN OPPORTUNITIES:
Ecological Enhancements
Urban Design
Form
  • N/A
  • N/A
  • N/A


DESIGN CONSIDERATIONS:

  • Depending on the type of gate, the footprint of the permanent structure will vary.
  • They can be designed to be fixed to any suitable structure.
  • They are normally attached to an adjacent structure or permanent protection, or else laid flat into a recess.
  • Heavy duty seals ensure the gates are watertight with no seepage and are typically EPDM rubber which is extremely durable and reforms even after prolonged periods of compression.
  • Due to their permanent installation, their deference height cannot be increased during service.
  • Automatic operation can be controlled by sensors, actuators, or direct hydraulic link to the watercourse.
  • Manual or semi-automated operation usually involves swinging, rolling, or raising into position.

SITE-SPECIFIC CONSIDERATIONS:

  • Because installed in a recess, need to be clear or not interfere with underground utilities

URBAN DESIGN CONSIDERATIONS:

  • Should not interfere with urban activities when not deployed

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • The gates would be manually installed and would remain permanently in place.
  • Gates should be mounted directly to a level watertight surface - i.e., banks and soil would require the construction of a concrete sill to ensure watertight seal.

ARCHITECTURAL CONSIDERATIONS:

  • Preferable if not visible when not deployed.

HISTORICAL RESOURCE CONSIDERATIONS:

  • Should not impact historical resources.

OPERATION AND MAINTENANCE CONSIDERATIONS:

  • The gates would be opened and closed mechanically; depending on design, operation would vary.
  • The gate entrance would need to be kept clear of obstructions so that closure is possible.
  • The bearings would need to be inspected and lubricated regularly to ensure successful operation.
  • Steel and aluminum gates typically have a 50 year design life, and the rubber seals can have a design life of up to 20 years before replacement.


Download the Mechanical and Bouyant Gates Factsheet.

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





NEED TO UPDATE

PHYSICAL INFRASTRUCTURE
SHORELINE LOCATION:
Shoreline or Asset Specific




DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
15 - 25+ years
Low
Minor Intervention
TBD


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


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


DESCRIPTION:
Mechanical and bouyant gates can provide permanent flood protection while still allowing access to the resources they protect. They are typically constructed with a steel gate, and a reinforced concrete foundation. They can also be fabricated in stainless steel and aluminum, making for lighter options than the equivalent steel gates. They are permanent in the sense that their foundation and location is permanent, but they are deployed (closed) only in storm and flood events. Gates are a proven concept and are reliable with adequate inspection and maintenance


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • NEED TO UPDATE
  • No installation or construction required during flood event.
  • Easy and quick operation.
  • No off-site storage or transportation required.
  • Stable and strong, with high resistance to impact.
  • Height cannot be increased during surface.
  • Possibility of failure of mechanical part of electricity supply (if automatic).
  • Structure could get jammed with debris.
  • Limited applicability at landscape scale.


CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
CASE STUDIES:
  • N/A
  • Not adaptable
  • None cited


DESIGN OPPORTUNITIES:
Ecological Enhancements
Urban Design
Form
  • N/A
  • N/A
  • N/A


DESIGN CONSIDERATIONS:

  • Depending on the type of gate, the footprint of the permanent structure will vary.
  • They can be designed to be fixed to any suitable structure.
  • They are normally attached to an adjacent structure or permanent protection, or else laid flat into a recess.
  • Heavy duty seals ensure the gates are watertight with no seepage and are typically EPDM rubber which is extremely durable and reforms even after prolonged periods of compression.
  • Due to their permanent installation, their deference height cannot be increased during service.
  • Automatic operation can be controlled by sensors, actuators, or direct hydraulic link to the watercourse.
  • Manual or semi-automated operation usually involves swinging, rolling, or raising into position.

SITE-SPECIFIC CONSIDERATIONS:

  • Because installed in a recess, need to be clear or not interfere with underground utilities

URBAN DESIGN CONSIDERATIONS:

  • Should not interfere with urban activities when not deployed

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • The gates would be manually installed and would remain permanently in place.
  • Gates should be mounted directly to a level watertight surface - i.e., banks and soil would require the construction of a concrete sill to ensure watertight seal.

ARCHITECTURAL CONSIDERATIONS:

  • Preferable if not visible when not deployed.

HISTORICAL RESOURCE CONSIDERATIONS:

  • Should not impact historical resources.

OPERATION AND MAINTENANCE CONSIDERATIONS:

  • The gates would be opened and closed mechanically; depending on design, operation would vary.
  • The gate entrance would need to be kept clear of obstructions so that closure is possible.
  • The bearings would need to be inspected and lubricated regularly to ensure successful operation.
  • Steel and aluminum gates typically have a 50 year design life, and the rubber seals can have a design life of up to 20 years before replacement.


Download the Mechanical and Bouyant Gates Factsheet.

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