Shoreline alterations in the Chesapeake Bay have led to a loss of native tidal and shallow water habitats throughout the waterways of the Bay. Efforts to reduce the proliferation of shoreline hardening through the use of Living Shorelines and similar restoration practices have slowed the loss of native habitats, but do not address areas that have already been hardened. Green Riprap is a low cost, simple restoration technique to improve the water quality, habitat, and aesthetics of shorelines previously hardened with rock revetments by planting marsh vegetation in the voids between riprap rocks. However, Green Riprap techniques are new to the Chesapeake Bay and before widespread use is encouraged, a synthesis of the science and identification of research gaps are needed. This workshop was developed to provide the foundation to evaluate the state of the science on Green Riprap and its potential for providing enhanced water quality, increased near shore biodiversity, and improved aesthetic functions of previously hardened tidal shorelines.
The workshop brought together scientists, practitioners, and NGOs to share aspects of shoreline systems that Green Riprap could contribute to and elucidate the best practices for their construction. The workshop was a single-day online meeting with an optional field trip to example Green Riprap projects. The workshop convened experts from multiple disciplines to evaluate the state of the science for Green Riprap, including estuarine scientists that study tidal wetlands and tidal shorelines, shoreline engineers, physical modelers, and social scientists. Several Green Riprap projects built by the U.S. Fish and Wildlife Service and other groups were shared through talks, a virtual field trip, and an in-person field trip. The talks were followed by discussion on the next steps forward. Results were a prioritized list of research questions related to: site criteria; plant species most effective for Green Riprap use; water quality criteria that could be used to assess project success; ecological benefits, including increased biodiversity; and social benefits, including increased recreational/aesthetic values made possible by Green Riprap habitats.
Key recommendations from the workshop include:
- Additional research to help understand both the best design of these shorelines and their benefits;
- Increased visibility of the technique through the creation of public pilot projects; and
- Additional outreach to all the involved parties, including property owners, contractors, and regulators to ensure clear definitions and that the projects are sited and designed correctly.
Potential partners for addressing these recommendations include the Chesapeake Bay Program’s Wetland and Fish Habitat Workgroups and the U.S. Fish and Wildlife Service.