Wednesday, March 21, 2018

Living Shorelines

The "Living Shorelines" concept for bay and estuarine management has been gaining momentum as an alternative to traditional coastal engineering.  The Surfers' Point Managed Shoreline Retreat project is often cited as a rare application of this approach on a high energy shoreline.

In 2017, the Resilient Coastlines Project led by the San Diego Climate Collaborative "brought together local decision makers and scientists to engage in thoughtful discussion and brainstorming for how to enhance the natural coastal landscape of our region, while building community resilience. Three workshops brought 150 regional leaders together in San Diego, Costa Mesa, and Santa Barbara."

The conclusion of these workshops was that:

  • "In Southern California, living shoreline projects are largely in the planning, designing, and early construction phases, so there is still much to be learned about the expanding practice. The participants in the Southern California Living Shoreline workshops represent leaders in our region and together they are laying the groundwork for advancing expertise and knowledge about living shorelines."











What is a Living Shoreline?

from the summary report:

Participants agreed that the term “living shoreline” is not easily defined but is an important concept for not only natural resource managers to understand but for city planners and government officials to embrace as they move forward with community plans. In its most basic form, a living shoreline must provide habitat while physically protecting the shoreline.

According to the National Oceanic and Atmospheric Administration (NOAA), a living shoreline is “a broad term that encompasses a range of shoreline stabilization techniques along estuarine coasts, bays, sheltered coastlines, and tributaries. NOAA further elaborates:

  • “[A] living shoreline has a footprint that is made up mostly of native material. It incorporates vegetation or other living, natural “soft” elements alone or in combination with some type of harder shoreline structure (e.g. oyster reefs or rock sills) for added stability. Living shorelines maintain continuity of the natural land–water interface and reduce erosion while providing habitat value and enhancing coastal resilience.”



The California State Coastal Conservancy (SCC) which has been the leading funder for pilot living shorelines projects in California, outlined four main principles for living shorelines: 
  1. restore with multiple benefits; 
  2. protect and enhance habitat values for fish and wildlife; 
  3. adapt to sea level rise and climate change; 
  4. link to regional habitat recommendations.
Living shoreline approaches began on the East Coast, where projects have been demonstrated and tested significantly more than on the West Coast. However, many of these model approaches are not applicable to Southern California because this region experiences high wave energy, seasonal El Nino storm events, and King Tide events. Successful living shoreline approaches also need to consider the uniqueness of Southern California coastal habitats and the fact that its coastal and ocean landscapes are heavily used and developed. Some potentially suitable approaches have recently been designed and tested in Southern California conditions. Examples of these early pilot projects include: The Cardiff Dune Restoration Project, the Santa Monica Beach Restoration Project, the San Diego Bay Native Oyster Restoration Project, and Ventura’s Surfers Point.


Insights:

Letting nature do the work for you:

As a living shoreline protects the coastline, natural weather events or seasonal cycles may damage the project site in the short-term but if it’s truly resilient it should be able to bounce back and restore itself to a functioning natural ecosystem.

Space constraints along urban coastlines:

Many participants expressed their idea of an ideal project integrating some form of “retreat” or “relocation” of infrastructure to create space for restoring natural coastal processes that can accommodate changing conditions. 

Living shorelines and phased sea level rise planning: 

Given the close proximity of development to Southern California shorelines it’s important to keep in mind that a living shoreline doesn’t need to be the final answer to sea level rise but may be a short term or mid-term option within a long-term vision.

Designing with watersheds and sediment management in mind:

participants were quick to discuss the importance of designing and monitoring coastal projects in the context of the broader watershed, especially when it comes to sediment management. Projects in the upper watershed (e.g., dams) can have huge implications for how much and what kind of sediment reaches our beaches to naturally replenish the sand supply.

Citizen science and socio-ecological monitoring:

Locals and tourists can be involved in monitoring activities through citizen science initiatives, and can even assist with long- term upkeep helping to lower maintenance costs by creating volunteer groups and involving students.


Next Steps:

  • Southern California needs demonstration projects 
  • Demonstration projects will need to incorporate long-term monitoring plans 
  • Monitoring should go beyond biological monitoring to ensure that information on the socio-economic benefits 
  • Consistent funding sources for both maintenance and monitoring will need to be identified
  • Permitting will need to be streamlined to support experimentation

References:

Boudreau, D., Engeman, L., & Ross, E. (2018). Living Shorelines and Resilience in Southern California: Workshop Series Summary Report. San Diego, CA: Tijuana River National Estuarine Research Reserve; San Diego Regional Climate Collaborative.

Living Shoreline Workshop series: www.resilientcoastlines.org/livingshorelines

Guidance for Considering the Use of Living Shorelines (2015), NOAA: http://www.habitat.noaa.gov/pdf/noaa_guidance_for_considering_the_use_of_living_shorelines_ 2015.pdf