Seawall Permits in the Florida Keys: Construction and Replacement

Waterfront properties in the Florida Keys depend on seawalls to protect shorelines, stabilize property, and provide access to the water. Whether you are building a new seawall or replacing a deteriorated structure that has reached the end of its useful life, the permitting process in Monroe County involves multiple agencies and requires careful preparation before construction can begin.

Understanding what the permit process requires — and what can cause it to stall — is essential for any property owner planning a seawall project in the Florida Keys.

Do You Need a Permit to Build or Replace a Seawall in the Florida Keys?

Yes. New seawall construction and seawall replacement in Monroe County require approvals from multiple agencies before any work can begin. This applies to all waterfront properties in the Florida Keys, including properties within the Florida Keys National Marine Sanctuary, which covers virtually the entire Monroe County coastline.

Beginning construction without the required permits can result in stop-work orders, significant fines, and mandatory restoration at the property owner’s expense — costs that far exceed what permitted construction would have required.

Who Regulates Seawall Construction in the Florida Keys?

Seawall projects in Monroe County fall under the jurisdiction of several agencies, each with its own application requirements and review timelines.

The U.S. Army Corps of Engineers (ACOE) has jurisdiction over construction in waters of the United States, including the tidal waters surrounding the Florida Keys. Most new seawall construction and seawall replacement projects require ACOE review. Depending on project size and environmental conditions, the project may qualify for a Nationwide Permit — which has a shorter review timeline — or may require an Individual Permit, which involves a more extensive review process.

The Florida Department of Environmental Protection (FDEP) issues Environmental Resource Permits (ERPs) for construction that affects Florida’s waters and wetlands. New seawall construction may require an ERP from FDEP. Full seawall replacement may meet the FDEP exemption criteria.

The Florida Keys National Marine Sanctuary (FKNMS) reviews construction projects within sanctuary boundaries to ensure they meet sanctuary standards for environmental protection. Because virtually all of Monroe County’s shoreline falls within the sanctuary, FKNMS is typically involved in the review of seawall projects in the Florida Keys.

Your local municipality — Monroe County, the Village of Islamorada, the City of Marathon, the City of Key Colony Beach, or the City of Key West — also issues a building permit for the construction phase. Local municipalities typically require confirmation from FDEP and ACOE before issuing their own approval.

What Does a Seawall Permit Application Require?

A complete seawall permit application in Monroe County typically includes the following:

Engineering drawings prepared and sealed by a Florida licensed Professional Engineer. These drawings document the proposed structure — materials, dimensions, pile spacing, water depths, and relationship to the shoreline and adjacent properties. Seawall permit applications in the Florida Keys typically require PE-sealed drawings.

A benthic survey of the project area is often required. ACOE, FDEP, and FKNMS routinely request benthic surveys to document seagrass, coral, sponges, and other seafloor resources in and around the proposed construction area. The survey data is used by agencies to evaluate the environmental impact of the project and determine what conditions or mitigation may apply. Glen Boe & Associates conducts benthic surveys in-house through our FKNMS-authorized biologist.

Environmental documentation addressing how the project avoids or minimizes impacts to waters of the United States, Florida’s wetlands, and sanctuary resources.

Agency coordination across ACOE, FDEP, FKNMS, and your local municipality. Each agency conducts its own review and may issue Requests for Additional Information (RAIs) during the process. A complete, well-prepared application reduces the likelihood of RAIs and keeps the review moving.

New Seawall Construction vs. Seawall Replacement — Is There a Difference in the Permit Process?

Both new seawall construction and full seawall replacement are treated as new construction for permitting purposes and follow the same general application process. The key differences are site-specific.

New seawall construction on a previously unprotected shoreline may require more extensive environmental documentation, particularly if the proposed structure would be placed over or adjacent to seagrass beds, mangroves, or other sensitive habitat. The location and alignment of the proposed structure relative to these resources is a primary factor in determining the scope of agency review.

Seawall replacement — removing an existing deteriorated structure and constructing a new one — follows the same permitting pathway. The condition and location of the existing structure may inform the design of the replacement, and agencies will evaluate the proposed replacement against the same environmental standards that apply to new construction.

How Long Does a Seawall Permit Take in the Florida Keys?

Seawall permit timelines in Monroe County depend on project complexity, the agencies involved, and the completeness of the application. A well-prepared application submitted to all agencies simultaneously moves faster than one that generates Requests for Additional Information (RAIs) or requires resubmission.

For projects that qualify for ACOE Nationwide Permits and do not require extensive FKNMS review, the permitting process can move relatively efficiently. Projects in areas with sensitive marine resources, or those requiring ACOE Individual Permits, typically take longer. Our post on how long dock permits take in the Florida Keys covers agency timelines in more detail.

Why Monroe County Seawall Permitting Requires Local Experience

Seawall permitting in the Florida Keys is more complex than in most waterfront areas of Florida. The combination of ACOE, FDEP, FKNMS, and local municipality requirements — applied within one of the most environmentally sensitive marine ecosystems in the United States — creates a regulatory environment that requires specific, local knowledge to navigate efficiently.

Firms that primarily work outside Monroe County are not as familiar with the sanctuary’s requirements, the local agency reviewers, or the site conditions that affect permitting outcomes in the Keys. Incomplete applications, incorrect permit pathway selections, and inadequate environmental documentation are among the most common causes of delay — and all are preventable with the right experience.

Glen Boe & Associates has been managing seawall permit applications in Monroe County since 1984. Our team includes a licensed Professional Engineer who prepares all engineering drawings in-house and an FKNMS-authorized biologist who conducts benthic surveys in-house. We have completed more than 7,770 projects throughout the Florida Keys.

If you are planning a new seawall or need to replace an existing structure, contact Glen Boe & Associates at (305) 743-9121 for a free site consultation. You can also visit our Seawall Design & Permitting page to learn more about our services throughout Monroe County.