MACARTHUR BOULEVARD RESILIENCE PROJECT

The Big Picture:

Martin County is a place of great natural beauty, but even here, climate change and some of its effects are having negative impacts on our environment. Similar to coastal communities around the country and the world, Martin County is vulnerable to heavy rainfall and flooding events, rising sea levels and coastal erosion, and increasingly stronger and more damaging storms.

For Martin County to be resilient, we must adapt to changing conditions at the local and global level. This requires long term planning and an investment of time and resources to reduce Martin County’s vulnerability and ensure we can handle future stresses to our fragile coastal community and infrastructure.

The Issue at Hand:

MacArthur Boulevard and Bathtub Beach are vulnerable to rising seas and stronger storms. Each year, frequently aligned with nor' easter storms, repeated and excessive erosion occurs along our barrier islands, and especially at Bathtub Reef Beach. This is only made worse with rising sea levels.

Bathtub Beach's submerged limestone reef can act as a natural breakwater when seas are relatively calm. However, when water levels are elevated during severe storms, this defense system isn’t effective. This process is amplified during high tides.

Large waves crash on the beach, erode the dunes, and leave no buffer between the volatile northeast seas and county infrastructure such as sidewalks, walkways, parking lot, roadway and utilities. Severe erosion has resulted in the protective dune system's total loss on many occasions.

Erosion at Bathtub Beach

MacArthur Boulevard, the road leading to Bathtub Reef Beach, is at high risk for road failure during these weather events. Whenever a major Atlantic storm erodes the beach and dune protecting Bathtub Beach Park, Martin County conducts emergency sand placement to prevent a complete failure of the roadway and loss of park amenities.

Truckloads of sand are transported to the area as a preventive measure to keep the ocean water from overwhelming the road. The sand brought there doesn’t protect or nourish the beach — it’s just a temporary measure to protect the road. The process needs to be repeated each time there is a major storm.

Current Road Elevation during Normal Conditions:

Current Shoreline during Sustained Storm Conditions:

Project Overview

A Better Way: The MacArthur Boulevard Resilience Project

There is a better way — better for residents and property owners, better for beach-goers, and better for our tax dollars. The goal of the MacArthur Boulevard Resilience Project is to stabilize the shoreline during extreme storm conditions, protect the public beach parking lot and road, and eliminate the need for costly and recurring emergency sand trucking activities.

The project is an opportunity to make the section of roadway at the entrance to Bathtub Reef Beach more resilient while maintaining the integrity and beauty of one of Martin County’s most beloved beaches.

How It Works:

The project targets the weak points of the road near Bathtub Reef Beach and “hardens” it in two phases: shoreline stabilization and roadway elevation. Simply put, here’s what’s going to happen:

Phase 1: Shoreline Stabilization

Build a barrier underneath the dunes just east of the parking lot of Bathtub Reef Beach to defend them during significant wave action.  Essentially, a seawall will be constructed and buried UNDER the dune line. This seawall will hold the line when storms have removed the sand from the beach and dune, keeping water and sand from overwhelming the beach parking lot, flooding MacArthur Boulevard, and damaging utilities that serve the area.

Unlike a typical seawall, however, this barrier WILL NOT BE VISIBLE to beach-goers under normal conditions. It will help to protect the public beach parking lot, roadway and utilities but won’t be seen from either the beach or the road except when major storms have eroded the entire beach and dune. Normal beach restoration will take place, as happens now, during periods of calm weather outside of turtle nesting season.

Phase 2: Roadway Elevation

The project will raise the roadbed in this vulnerable section of MacArthur Boulevard – between Bathtub Beach and Sailfish Point – to prevent its loss due to storms. This 1,100-foot section of roadway along MacArthur Boulevard has a current elevation of 2.5 feet, is vulnerable to flooding, and doesn’t meet FEMA's minimal elevation guidelines.

Through this project, the roadway will gradually be raised with successive layers of paving material (macadam), until it is 5.25 feet above sea level. The sidewalk and parking lot will remain, and new Stormwater Quality Retention ponds will be created for stormwater treatment. The road will also be slightly widened to allow for easier access into the Bathtub Beach Reef parking lot and into Sailfish Point during times of high traffic.

A Protected Solution for MacArthur Boulevard:

A more Resilient Road during Sustained Storm Conditions:

A Solution That Works

Resilient: We can’t stop storms, but through engineering solutions we can lessen the impact to MacArthur Boulevard - the singular road that leads to Bathtub Reef Beach.

Environmentally Smart: Besides protecting this vulnerable area, the project includes stormwater drains that will increase the protection of our waterways from storm runoff. Currently, stormwater runs off directly into the lagoon, without treatment.

A federal environmental assessment (EA) involving U.S. Fish and Wildlife (USFWS) and U.S. Environmental Protection Agency (EPA) was completed to evaluate all possible solutions and identified that the shoreline armoring and roadway elevation as the preferred solution. 

Fiscally Sound: The Federal Government and Martin County have spent millions of dollars over the last decade trucking in sand to protect MacArthur Boulevard before oncoming storms and to repair the road after storms have taken out the dune.

We can mitigate these recurring costs and save money and labor by addressing a root cause and fixing it. We can also avoid the significant costs of repairing a washed-out road and utilities along the roadway when the storm subsides.

A grant from the Federal Emergency Management Agency (FEMA’s) Hazard Mitigation Grant Program (HMGP) will provide 75% of the cost of this project to improve the structural integrity and drainage on MacArthur Boulevard. Martin County will provide the additional funding, which will result in savings year after year as the need for emergency sand is eliminated. 

The final cost of the project is be determined after FEMA completes its Environmental Assessment and bids are announced and awarded. Approximate cost estimates range between $7-8 million.

This Martin County initiative will help mitigate the future impacts of sea-level rise on MacArthur Boulevard and is part of our county’s commitment to creating more permanent and resilient solutions to protect our most vulnerable resources and critical infrastructure.

FAQs

This is a project to protect valuable infrastructure – the County park and an evacuation route – from impacts attributed to climate change.  Higher water levels now flood the road frequently during King Tides. More powerful storms and higher water levels accelerate erosion.

MacArthur Boulevard is the access to Bathtub Beach for both residents and tourists. It also serves as an evacuation route for local residents.  It has economic importance for local and regional businesses that routinely work at residences along MacArthur Boulevard and within Sailfish Point as well as staff that work at Sailfish Point.

This area is an extremely low lying section and very narrow section of the barrier island. There is only around 150 feet at the narrowest point of land separating the Atlantic Ocean from the Indian River Lagoon. 

Rising water levels are already impacting roads around the County.  The County is addressing these issues as “pilot projects,” identifying alternative solutions and performing cost/benefit analyses to provide Commissioners with the best, most current information when addressing larger, more numerous projects for the future.

No.

The shoreline armoring, or wall, will eliminate the need for emergency projects requiring the trucking of sand. However, as needed, regular maintenance or beach nourishment projects will be scheduled when seas are calmer and more hospitable to construction activities, outside of sea turtle nesting season.

Except for the construction of the dune wall, which will take about four months, Bathtub Reef Beach will not be affected by the project.

The parking lot will not be affected.

To be clear, this is a storm protection project and not a beach renourishment project, so Bathtub Reef Beach will still be vulnerable to strong storms that cause erosion and require beach closures for periods of time.

This project will not eliminate the need for renourishment.

Traffic will continue to flow on MacArthur where the road is being raised, but at times there will be one lane only. The construction period for raising the road will be about six months long. This phase of the project takes place after the dune wall has been completed.

The beach entrance will remain open.

That depends. The County determines when to open and close the beach for visitor safety. Bathtub Beach is a seasonal beach, typically open to the public during the warmer spring and summer months, when the water is calm, and the beach allows for lifeguard towers and ADA access.

As nor’easter storms resume, the beach can become dangerous as it loses its bathtub-like features. Potential hazards such as severe drop-offs develop, and rough waters are present.

The beach is often closed during the regular winter season and may not reopen to the public until safe conditions return. The County provides regular updates on Bathtub Beach closures as well as alternative beach locations, which are plentiful in Martin County!

The gazebo, mangroves, and parking area will all be in place at the conclusion of the project. The sidewalk will be temporarily removed during construction and a new one will be built along with the seawall installation.

Periodic delays will occur. Please be patient and understanding of the process. The traffic will be closed to one lane during paving and drainage construction work. Bathtub Beach Park will also be closed during active construction activities.

A bridge was evaluated explicitly as part of the Federal Environmental Assessment process performed as a prerequisite to granting funding of this construction project.

During this process, it was determined the bridge option was too costly and provided a more negative environmental impact than the proposed shoreline stabilization.

  • December 31, 2021: Comment period for FEMA’s Environmental Assessment ends.
  • January-February 2022: FEMA concludes Environmental Assessment.
    • Post-Assessment: FEMA grants construction funding and bidding process begins.
    • Bids are received and awarded according to County process.
  • November 2022 through May 2023 : Expected time frame for Phase 1.
  • May 2023 through April 2024: Expected time frame for Phase 2.

A grant from the Federal Emergency Management Agency (FEMA’s) Hazard Mitigation Grant Program (HMGP) will provide 75% of the cost of this project to improve the structural integrity and drainage on MacArthur Boulevard. Martin County will provide the additional funding, which will result in savings year after year as the need for emergency sand is eliminated. 

The final cost of the project is be determined after FEMA completes its Environmental Assessment and bids are announced and awarded. Approximate cost estimates range between $7-8 million.

FEMA’s Base Flood Elevation is the elevation of surface water resulting from a flood with a 1% chance of equaling or exceeding that level in any given year, also known as the height of the water that is expected in a 100-year storm.

Engineers use this data to determine the minimal elevation of residential structures. MacArthur Boulevard will be slightly above the minimum FEMA standards when it is completed.

Studies have shown that every $1 spent on preventing recurring damages saves a community $6 or $7 dollars in repairs after a storm. It is therefore in FEMA’s interest and that of our local community to take actions that prevent or lessen damages.

These actions also benefit every community member because of the effect on the Community Rating System for identifying and evaluating flood zones. Mitigating the damages caused by flooding stands to lessen insurance rates for property owners and local governments.

Emergency work requires hundreds of trucks that bring sand from an upland mine that is dumped on the seaward side of the parking lot to protect the park facilities and MacArthur Blvd. It does not build a beach and is typically gone by the time calmer water conditions return. 

A beach renourishment project at Bathtub Beach recycles the sand that has eroded from the beach, been swept down the beach, and deposited in the impoundment basin, just inside St. Lucie Inlet.

Road Closures

Stay tuned! The county will provide regular updates on the duration of closures and offer alternative traffic detours. You may also view project status updates for the MacArthur Boulevard Resiliency Project below.

Beach Nourishment in America: In the video below, watch the TEDx Talk with John Hearin on Beach Nourishment in America and visit our Resilient Martin homepage via the button below, where you can find more information, resources and tools to enable residents, businesses, and property owners to continue to thrive, even in the face of our changing climate.