In 2022, Miami sank 345 tons of concrete from a demolished waterfront pier instead of dumping it; the rubble became a reef rising 8 feet from the seafloor

When a waterfront structure reaches the end of its life, demolition usually marks the beginning of a waste problem. Concrete is broken apart, removed, and then ignored. In the case of Miami, however, demolition resulted in quite the opposite situation when the ruins of the pier did not end up in some landfill but started their new life at the bottom of the ocean. Instead of ending the existence of concrete, hundreds of tons of it found a new purpose beneath the water and turned into a brand new artificial reef created to provide a home for the marine inhabitants.

According to Miami-Dade County’s Artificial Reef Program, 345 tons of secondary-use concrete from the demolished Bentley Bay Pier were deployed in December 2022 at the Julia Tuttle Artificial Reef Site, creating a structure that rises about 8 feet above the seafloor. The project transformed a piece of aging waterfront infrastructure into an underwater habitat. What was once part of a working pier now serves a new purpose below the waves, providing a hard surface where marine organisms can attach, grow, and create a developing ecosystem.

From demolished structure to marine habitat


The Bentley Bay Pier Project is just one of the many artificial reef projects that Miami-Dade County embarked on to help promote the establishment of a marine-friendly environment through construction. In the past few years, instead of taking the materials to the dump site, the county began making artificial reefs that would help mimic natural rocks in the marine environment.

The installation of this particular reef took place at the Julia Tuttle Artificial Reef Site, where the concrete pieces were placed on the ocean floor in 27 feet of water. Over time, these surfaces become habitat for animals like barnacles, corals, sponges, and other reef-building organisms that require hard surfaces to settle.

Artificial reefs do not turn into marine life habitats overnight. They take time to develop as marine organisms form colonies on top of the structures. Small organisms create the foundation, attracting larger species that use the structures for shelter and feeding areas. Eventually, the once-bare concrete can become part of a more complex underwater environment.

How concrete became marine habitat

The project was designed to reuse demolition material while creating additional hard surfaces where marine organisms could establish themselves. These projects are designed not only to expand marine habitat but also to support fisheries management and provide additional locations for recreational diving. By incorporating suitable materials into reef projects, Miami-Dade’s programme links coastal infrastructure management with long-term marine conservation goals.

A second life beneath the waves

Beyond creating habitat, the Bentley Bay Pier reef represents a shift in how coastal cities view materials left behind by development. Instead of separating construction projects from environmental goals, Miami-Dade’s approach shows how urban infrastructure can be redesigned to contribute to marine conservation. The project connects two traditionally separate worlds, that is, coastal development and ecosystem restoration, by allowing a structure built for human use to support life beneath the ocean.

Cities are now looking into reusing materials from demolished projects for environmental purposes. The artificial reef project in Miami-Dade demonstrates how decisions made in waterfront redevelopment can aid marine conservation by recycling parts of the built environment and utilizing them underwater for another purpose. The Miami-Dade Reef Programme has been using approved materials such as concrete structures, vessels, and limestone to create more marine habitats.

A new future for aging infrastructure

The Bentley Bay Pier reef shows how demolition projects can be reconsidered as opportunities for environmental restoration. By redirecting suitable construction materials away from waste streams, coastal cities can create new habitats while managing the impacts of urban development. A material used to build structures for people has been used to build structures for marine life.