Suitable Sites for Living Shorelines in Tampa Bay
Protect your property and our Bay!
Tampa Bay's Erosion Crisis
In Tampa Bay, crumbling seawalls and fading beaches are common sights. Rising tides, wave energy, and storm impacts are affecting our bay's shoreline and washing away waterfront property. This erosion is influencing property values, inflating maintenance costs, diminishing recreational opportunities, and threatening breeding habitat for the bay's fish and wildlife species.
Natural energy eroding and undermining bulkhead. ( CT Mirror )
Historically, the response to this erosion crisis has been to install manufactured armor, such as bulkheads, designed to retain the soil in place while deflecting wave energy away from the property. These installations, often called "hardened shorelines," can be very costly to install and maintain. In practice, hardened shorelines become vulnerable to erosion caused by natural processes, such as tidal fluctuation, wave energy and severe storm events.
After the installation of a hardened shoreline, these natural energy sources are reflected away from the bulkhead to affect neighboring properties. Additionally, the energy is deflected downward, scouring the sediment at the footings and undermining the bulkhead. Eventually, the bulkhead will collapse and the wave energy will wash over and erode the property and adjacent properties.
In more recent years, living shorelines have been offered as a sustainable and softer, or "green," alternative to a armored shoreline.
What is a Living Shoreline?
The National Oceanic and Atmospheric Administration defines a living shoreline as:
A shoreline management practice that provides erosion control benefits; protects, restores, or enhances natural shoreline habitat; and maintains coastal processes through the strategic placement of plants, stone, sand fill, and other structural organic materials"
The strategic placement of natural materials, such as wetland plants, oyster shell, coir fiber logs, sand, wood and native rock can offer a long-lasting and low maintenance cost solution to shoreline erosion. These materials may actually work with the tidal influences and wave energy to allow new sedimentation on the property and a more resilient shoreline.
Benefits of a Living Shoreline
Protecting Your Property
- Reduce wave energy and associated shoreline erosion (property loss).
- Reduce storm water flow rates thereby reducing erosion and reducing pollution entering the bay or estuary.
- Buffer the effects of storms, especially tropical storms and hurricanes.
- Build up shoreline areas by trapping sediments and stabilizing coastal land.
Keeping Our Bay Healthy
In addition to the mentioned property improvements, this NOAA National Ocean Service info graphic (right) lists a variety of ecological benefits to living shorelines.
- Ensure natural sediment movement along shorelines.
- Improve water quality in our bays and estuaries by filtering pollutants like a living “kidney."
- Provide for shorelines that are resilient to storm damage and sea level rise – A gradually sloping interface between land and sea helps maintain a plant community that can adapt as sea level rises.
- Trap carbon to help reduce the effects of climate change.
- Create and connect diverse animal habitats, provide migratory pathways for plants and animals, and support valuable fisheries.
Provide Recreational Opportunities
- Provide recreational opportunities for people – fishing, kayaking, paddle-boarding, and wildlife viewing are all better where there’s habitat.
- Beautify shorelines.
Types of Shoreline Protection
Systems Approach to Geomorphic Engineering (SAGE), a Community of Federal, State, and Local Agencies, non- governmental organizations, academic institutions, engineers, and private business practitioners, has developed a spectrum of shoreline protection solutions. These solutions, depicted below, range from the most vegetated, or "green," to manufactured, or "gray," solutions.
Green or Soft engineering options are often less expensive than hard engineering options. They are usually also more long-term and sustainable, with less impact on the environment.
Gray or Hard engineering options tend to be expensive and short-term options. They may also have a high impact on the landscape or environment.
Green to Gray Spectrum of Shoreline Protection Solutions. A full description of the shoreline solutions are available in SAGE's Living Shoreline Brochure .
Below, SAGE's spectrum has been generalized to six potential solutions to shoreline erosion with outlines of environments where each example may be most effective and the benefits and disadvantages to each option.
Bulkhead
Parallel to the shoreline, vertical retaining wall. Intended to hold soil in place and allow for a stable shoreline.
Suitable for high energy sites with pre-existing hardened shoreline structures. Can accommodate working water fronts.
Benefits:
- Moderate wave action
- Manages tide level fluctuation
- Long lifespan
- Simple repair
Disadvantages:
- No major flood protection
- Erosion of seaward seabed
- Erosion of adjacent unreinforced sites
- Loss of inter-tidal habitat
- Potential damage from over-topping oceanfront waves
- Prevents upland from being a sediment source to the system
- Induces wave reflection
Revetment
Lays over the slope of a shoreline. Protects slope from erosion and waves.
Suitable for sites with pre-existing hardened shoreline structures.
Benefits:
- Mitigates wave action
- Little maintenance
- Indefinite lifespan
- Minimizes adjacent site impact
Disadvantages:
- No major flood protection
- Require more land area
- Loss of intertidal habitat
- Erosion of adjacent unreinforced sites
- No high water protection
- Prevents upland from being a sediment source to the system
Breakwater
Offshore structures intended to break waves, reducing the force of wave action and encourages sediment accretion.
Suitable for most areas except high wave energy environments often in conjunction with marinas.
Benefits:
- Reduces wave force and height
- Stabilizes wetland
- Can function like reef
- Economical in shallow areas
- Limited storm surge flood level reduction
Disadvantages:
- Expensive in deep water
- Can reduce water circulation
- Can create navigational hazard
- Require more land area
- Uncertainty of successful vegetation growth and competition with invasive
- No high water protection
Sills
Parallel to vegetated shoreline, reduces wave energy and prevents erosion. A gapped approach allows for habitat connectivity, tidal exchange, & waterfront access.
Suitable for most areas except high wave energy environments.
Benefits:
- Provides habitat and ecosystem services
- Dissipates wave energy
- Slows inland water transfer
- Provides habitat and ecosystem services
- Increases natural storm water infiltration
- Toe protection helps prevent wetland edge loss
Disadvantages:
- Requires more land area
- No high water protection
- Uncertainty of successful vegetation growth and competition with invasive.
Edging
Structure to hold the toe of existing or vegetated slope in place. Protects against shoreline erosion.
Suitable for most areas except high wave energy environments.
Benefits:
- Dissipates wave energy
- Slows inland water transfer
- Provides habitat and ecosystem services
- Increases natural storm water infiltration
- Toe protection helps prevent wetland edge loss
Disadvantages:
- No high water protection
- Uncertainty of successful vegetation growth and competition with invasive.
Vegetation Only
Roots hold soil in place to reduce erosion. Provides a buffer to upland areas and breaks small waves.
Suitable for low wave energy environments.
Benefits:
- Dissipates wave energy
- Slows inland water transfer
- Increases natural storm water infiltration
- Provides habitat and ecosystem services
- Minimal impact to natural community and ecosystem processes
- Maintains aquatic/terrestrial interface and connectivity
- Flood water storage
Disadvantages:
- No storm surge reduction ability
- No high water protection
- Appropriate in limited situations
- Uncertainty of successful vegetation growth and competition with invasive.
Is a Living Shoreline right for me?
To decide if a living shoreline is right for your property and situation, the Florida Living Shoreline website provides a flow chart with a series of questions that will help you come to a decision. Additionally, the Virginia Institute of Marine Science (VIMS) developed a Living Shoreline Suitability Model (LSSM) that uses mapping software to predict the potential for successful living shoreline installment. VIMS recently converted this mapping product into a decision support tool that steps users through the process of identifying an suitable shoreline protection method for their property.
For a more general look at the Tampa Bay shoreline, the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute applied the VIMS LSSM using the best available information on existing shoreline and environmental factors. Click, pan, and zoom around the below map to explore the generalized results for your area.
Explore the results of the Tampa Bay Living Shoreline Suitability Model.
Additional Resources
Thanks
The Tampa Bay Estuarynvironmental Restoration Fund and the Gulf of Mexico Alliance funded the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute to apply the Virginia Institute of Marine Science's (VIMS) Living Shoreline Suitability Model (LSSM) to Tampa Bay, Florida.
