Living shorelines use a combination of bank stabilization and habitat restoration techniques to reinforce the shoreline, minimize coastal erosion, and maintain coastal processes while protecting, restoring, enhancing, and creating natural habitat for aquatic plants and wildlife. Living shoreline projects are constructed using a variety of structural and organic materials, such as wetland plants, submerged aquatic vegetation, oyster reefs, coir fiber logs, sand fill, and stone. In addition to shoreline stabilization and erosion control, living shorelines provide added benefits, such as reduction of wave energy, absorption of storm surge, improved water quality via filtration, protection of riparian and intertidal resources, and creation of aquatic and terrestrial habitat.
Incorporating living shoreline designs into seawall projects helps to create habitat and can serve as additional mitigation requirements for unavoidable impacts. The City will be retaining a coastal engineering firm to conduct a Citywide living shoreline site viability assessment. The assessment will be high level to understand overall potential for including nature -based solutions to stabilize shorelines and increase resilience of City property and possibly providing water quality treatment for grey infrastructure. The assessment will include a feasibility report, environmental resource survey, three conceptual designs, and funding strategy development. The assessment will be used to compliment the seawall prioritization list and will be used to pursue grant opportunities. The living shoreline assessment is fully funded and is anticipated to be complete by October 2021.
Living Shoreline Projects
There are a number of living shoreline projects that are currently in design or construction, in increased order of progress, include the Maurice Gibb Park seawall project, the Brittany Bay Park seawall project, and the Lake Pancoast Mangrove Shoreline project.
Maurice Gibb Park
The Maurice Gibb Park project includes the raising the concrete seawall to an elevation of +5.7’ NAVD, including over 400 linear ft of stepped seawall with rip-rap that will allow park patrons to sit along the water’s edge. Limestone rock rip-rap provides habitat for fish, crustaceans, and other marine life. At the southern end of the park, there is over 100 ft of natural red mangrove shoreline. This project will include enhancing the mangrove shoreline, removing the fence enclosure, and improving the overwater boardwalk to minimize impact to the natural area. The project is currently under permitting phase, pending Miami-Dade County Division of Environmental Resources Management (DERM) Class I and the U.S. Army Corps (USACE) permits. Once the permits are conceded, the project will go through a competitive procurement process for construction, anticipated for August 2021. Construction is expected to begin in January 2022.
Brittany Bay Park
The Brittany Bay Park hybrid living shoreline project includes the construction of a concrete retaining/seatwall east of the old seawall (Attachment A). The area between the seatwall and the water’s edge will be planted with native, wetland vegetation to create a living shoreline. The living shoreline will be hydraulically connected to Indian Creek and will have an ADA-accessible overlook that will allow park patrons to walk from the park to the existing seawall’s edge. These improvements will not only revitalize the waterfront, but also enhance the surrounding riparian and intertidal environment by creating new habitat for aquatic and terrestrial species and improving water quality via filtration of upland run-off. A contractor has been awarded the construction of the project at the last Commission meeting on June 12, 2020, and construction is anticipated to begin within the next months.
Lake Pancoast Living Shoreline
The Lake Pancoast Living Shoreline project proposes to install the City’s first mangrove planter at the south end of the project at 25th Street (Attachment B). This project is currently in the permitting phase, pending permits from DERM and the USACE. Once the permits are granted, the project will go through competitive procurement process for construction. Construction is anticipated to begin in FY22/23.