City Initiates Process to Revise Seawall Standards and Elevations
Published on January 14, 2020
In order to create a more resilient waterfront, the City of Miami has begun the process of revising standards for seawalls and waterfront barriers within the city code. Currently, the City requires seawalls to be constructed to +5 ft NVGD (National Geodetic Vertical Datum standard) north of the Rickenbacker Causeway, +6 ft NVGD south of the Rickenbacker Causeway, and +5.5 ft NVGD along the Miami River.
The most recent projections developed by the South Florida Regional Climate Compact indicate Miami must be prepared for 21” to 40” of Sea Level Rise within the next 50 years (2070). Given that the expected lifespan of waterfront infrastructure is 50 years, this will require seawalls and natural waterfront barriers to be constructed to a higher elevation to prevent inundation during king tides, hurricanes, and extreme weather events.
In addition to seawall elevations, the City intends to incorporate several other changes, including transitioning from NGVD to North American Vertical Datum of 1988 (NAVD) as the standard for elevation data, establishing standards for natural waterfronts and permeable erosion barriers, and triggers for when property owners must improve waterfronts to the new standard.
Proposed changes will be presented to stakeholders and the public for comment in the coming months, with final recommendations to be given to the Miami City Commission in late Spring 2020.