USACE BackBay Study I Gray-Green Infrastructure

City of Miami, FL

 

Working for the Miami Downtown Development Authority (DDA) -- a longstanding public agency that advocates for the city’s urban core and its jobs, density, transportation, and viability Curtis and Rogers lead exploring an alternative to the U.S. Army Corp of Engineers (USACE) proposed 20-feet-tall seawall. The DDA gave us two weeks to create nature-based alternatives to be shared with the Corps.

The solution – exportable to virtually all coastal areas in our great nation – is a hybrid of nature-based features -- such as barrier islands, living shorelines, nearshore artificial reefs, and mangrove fringes in coastal areas -- and elevated berms and bioswales in upland areas, with some smaller floodwalls as a layered and tiered defense.  This approach is flexible and adaptable. Breakwaters and upland improvements can be raised over time to stay ahead of the perils of increasing sea level rises.

 

The man-made barrier islands can add refuge for a variety of wildlife as well and an inclusive new chain of natural areas accessed by a series of boardwalks. People of all incomes and physical abilities could enjoy unprecedented access to Miami’s famed Biscayne Bay without the need for an expensive boat or waterfront condo. We could protect our region’s economic engine while addressing social justice in a city with a great chasm between the haves and have nots.

 

There are dozens of reasons while designing in harmony with nature is the best solution to Sea Level Rise. The key facts are:

 

  1. For centuries, coastal communities have depended on natural barriers -- such as mangroves and coral reefs -- to aid in flood reduction during hurricanes.

  2. Studies have shown that shellfish and coral reefs can provide protection against harmful waves comparable to gray (seawalls) solutions. National Oceanic and Atmospheric Administration studies have proven a healthy coral reef can protect people and property by absorbing 97 percent of the wave energy from storms and hurricanes,

  3. The USACE’s Engineering with Nature Strategic Report (2018-2023) states that: “the pursuit of integrated natural and engineered systems will achieve more socially acceptable, economically viable & environmentally sustainable projects.”

  4. The Miami model for climate adaption – using landscape architecture to lead a diverse team of designers, scientists, and engineers -- could become the nation’s template for replacing gray walls with natural, durable, and accessible lines of defense.