Floating Wetlands

Measure under the Aquatic Habitat measures related to ecological infrastructure opportunities to address flood risk.

Looking for more? Head back to the Measures Explorer to check out other flood and seismic measures.


Manmade floating wetlands for water fowl – Baltimore, MD ©Gallery via commons.wikimedia.org
DESCRIPTION:
Constructed Floating Wetlands (CFWs) are designed and constructed ecosystems that mimic naturally occurring floating wetlands observed in various waterways around the world. Floating wetlands can serve a number of functions, such as creation of habitat and food production for various fish and wildlife species, reduction of wave energy approaching the shoreline, and/or improvement of water quality and clarity.



ECOLOGICAL INFRASTRUCTURE:
WATER LEVEL RANGE: Intertidal

SHORELINE LOCATION: In Water




DESIGN LIFE:
ADAPTABILITY:
IMPACT ON THE WATERFRONT:
CONSTRUCTION COST:
5 to 10 years
High, Medium, Low
Minor Intervention
TBD




COASTAL FLOOD HAZARDS MITIGATED:
Enhancements can provide flood protection when combined with other physical infrastructure





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




CONSIDERATIONS:

ADVANTAGES:

DISADVANTAGES:





  • CFWs have had fairly wide usage in freshwater lakes and ponds as a water treatment technology, but experience from deployment in saltwater environments is fairly new and limited.
  • Can provide some wave attenuation but only for relatively small, short period waves.
  • Should not be used in high wave energy environments. Consideration should be given to sheltered environments.

  • Ability to adapt to varying water levels.
  • Can improve water quality through nutrient removal and encouraging deposition of suspended sediments.
  • Can provide riparian and fish habitat as well as food production for many species of fish and wildlife.

  • Generally, have little topographic relief with wetting and drying during the tidal cycle, limiting ecological diversity of habitats.
  • Technology for use in saltwater/estuarine environments is in its infancy.
  • Existing commercially available floating wetlands have a relatively short lifespan and would likely require ongoing maintenance and periodic replacement.
  • Limited to low wave energy environments.




CONSTRUCTION IMPACTS TO THE PUBLIC:

SEA LEVEL RISE ADAPTATION OPPORTUNITIES:

CASE STUDIES:





  • Floating wetlands are typically constructed off-site and towed to the site and installed from the water. Construction impacts would be short term and limited to on-water uses.

  • CFWs float on the surface of the water and therefore adapt to varying sea levels.

  • Baltimore Inner Harbor




DESIGN OPPORTUNITIES:





Ecological Enhancements

Urban Design

Form
  • Provides nearshore habitats and enhances biodiversity and food supply for wildlife. Improves water quality.

  • Habitat creation and associated wildlife and provide educational opportunities as well as additional greening of the waterfront.

  • Form should be designed to maximize sustainability and habitat value.




DESIGN CONSIDERATIONS:

  • Moorings should be designed to resist current and wave environment as well as potential impacts from floating debris or recreational watercraft.
  • Moorings
  • must accommodate expected water level variations/changes over the life of the project.Vegetation should be native and compatible with site salinity, exposure and water quality.
  • Design should allow access to the wetland platform for periodic maintenance.


SITE-SPECIFIC CONSIDERATIONS:

  • Wave and current conditions should be well defined.
  • Conditions at the site should be consistent with the needs of the target vegetation/habitat.


URBAN DESIGN CONSIDERATIONS:

  • Should consider potential for recreational water users to try to use CFWs as rest stops or platforms.


INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • Can be manufactured and planted off-site and towed into place.


OPERATIONS AND MAINTENANCE CONSIDERATIONS:

  • Initial monitoring and maintenance required to ensure that vegetation becomes successfully established.
  • Ongoing monitoring and maintenance will be required to evaluate.



Other Types of Aquatic Habitat:
Click the images and links below to explore other types of Aquatic Habitat.


Tide Pool UnitsNearshore Reef



Eelgrass Restoration



Head back to the Measures Explorer to check out other flood and seismic measures.


Measure under the Aquatic Habitat measures related to ecological infrastructure opportunities to address flood risk.

Looking for more? Head back to the Measures Explorer to check out other flood and seismic measures.


Manmade floating wetlands for water fowl – Baltimore, MD ©Gallery via commons.wikimedia.org
DESCRIPTION:
Constructed Floating Wetlands (CFWs) are designed and constructed ecosystems that mimic naturally occurring floating wetlands observed in various waterways around the world. Floating wetlands can serve a number of functions, such as creation of habitat and food production for various fish and wildlife species, reduction of wave energy approaching the shoreline, and/or improvement of water quality and clarity.



ECOLOGICAL INFRASTRUCTURE:
WATER LEVEL RANGE: Intertidal

SHORELINE LOCATION: In Water




DESIGN LIFE:
ADAPTABILITY:
IMPACT ON THE WATERFRONT:
CONSTRUCTION COST:
5 to 10 years
High, Medium, Low
Minor Intervention
TBD




COASTAL FLOOD HAZARDS MITIGATED:
Enhancements can provide flood protection when combined with other physical infrastructure





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




CONSIDERATIONS:

ADVANTAGES:

DISADVANTAGES:





  • CFWs have had fairly wide usage in freshwater lakes and ponds as a water treatment technology, but experience from deployment in saltwater environments is fairly new and limited.
  • Can provide some wave attenuation but only for relatively small, short period waves.
  • Should not be used in high wave energy environments. Consideration should be given to sheltered environments.

  • Ability to adapt to varying water levels.
  • Can improve water quality through nutrient removal and encouraging deposition of suspended sediments.
  • Can provide riparian and fish habitat as well as food production for many species of fish and wildlife.

  • Generally, have little topographic relief with wetting and drying during the tidal cycle, limiting ecological diversity of habitats.
  • Technology for use in saltwater/estuarine environments is in its infancy.
  • Existing commercially available floating wetlands have a relatively short lifespan and would likely require ongoing maintenance and periodic replacement.
  • Limited to low wave energy environments.




CONSTRUCTION IMPACTS TO THE PUBLIC:

SEA LEVEL RISE ADAPTATION OPPORTUNITIES:

CASE STUDIES:





  • Floating wetlands are typically constructed off-site and towed to the site and installed from the water. Construction impacts would be short term and limited to on-water uses.

  • CFWs float on the surface of the water and therefore adapt to varying sea levels.

  • Baltimore Inner Harbor




DESIGN OPPORTUNITIES:





Ecological Enhancements

Urban Design

Form
  • Provides nearshore habitats and enhances biodiversity and food supply for wildlife. Improves water quality.

  • Habitat creation and associated wildlife and provide educational opportunities as well as additional greening of the waterfront.

  • Form should be designed to maximize sustainability and habitat value.




DESIGN CONSIDERATIONS:

  • Moorings should be designed to resist current and wave environment as well as potential impacts from floating debris or recreational watercraft.
  • Moorings
  • must accommodate expected water level variations/changes over the life of the project.Vegetation should be native and compatible with site salinity, exposure and water quality.
  • Design should allow access to the wetland platform for periodic maintenance.


SITE-SPECIFIC CONSIDERATIONS:

  • Wave and current conditions should be well defined.
  • Conditions at the site should be consistent with the needs of the target vegetation/habitat.


URBAN DESIGN CONSIDERATIONS:

  • Should consider potential for recreational water users to try to use CFWs as rest stops or platforms.


INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • Can be manufactured and planted off-site and towed into place.


OPERATIONS AND MAINTENANCE CONSIDERATIONS:

  • Initial monitoring and maintenance required to ensure that vegetation becomes successfully established.
  • Ongoing monitoring and maintenance will be required to evaluate.



Other Types of Aquatic Habitat:
Click the images and links below to explore other types of Aquatic Habitat.


Tide Pool UnitsNearshore Reef



Eelgrass Restoration



Head back to the Measures Explorer to check out other flood and seismic measures.


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