Making Key West Safer for Children, Pedestrians and Cyclists

The City of Key West is looking for ways to allow pedestrians and cyclists safer access to its public beaches. A pedestrian bridge is in consideration to connect Government Road over the Salt Ponds to Smathers Beach, which would, in turn, reduce accidents and enhance the journey experience.

The primary challenges that were determined in the evaluation were to avoid impacts in mangroves and seagrass, as well as avoiding blocking access to the pump station, which would help minimize the footprint within the airport’s runway protection zone (RPZ). The airport’s RPZ encompasses most of the site. The main purpose of the RPZ is to enhance the protection of people and property on the ground. Land uses prohibited from the RPZ are residences and places of public assembly.

The salt ponds are surrounded by red mangroves (Rhizophora mangle), black mangroves (Avicennia germinans) and green buttonwood trees (Conocarpus erectus). To the north of the site is Government Road. Branching off Government Road to the southwest is a gravel road that leads to a City pump station. Benthic organisms observed included shoal grass (Halodule wrightii), and macroalgae Halimeda opuntia, Caulerpa mexicana and Acetebularia acetabulum.

In September 2023, Resource Environmental Solutions (RES) marine biologists conducted the wetland and benthic resources survey. The purpose of the survey was to assess and document the status of marine habitats and species in the area to explore potential access options to the site and path locations., The study area includes 32.96 acres of salt ponds, which is bordered by roads and residential properties.

GHD, along with RES marine biologists, was contracted to provide a concept study for the Salt Pond Pedestrian Trail that included analyzing the benthic and existing conditions present in the salt ponds, proposing alternative paths, presenting the preferred alternative and assessing the likelihood of acquiring state and federal permits.

The concept study presents the existing marine resources of the salt pond and a potential design path for the pedestrian trail. As part of the study, mangrove species, wetland vegetation, upland vegetation and listed species were documented, and regionally important and invasive/exotic trees were defined.

We evaluated four path alternatives taking into consideration the primary challenges of this project. Each path was evaluated as 12 feet wide and 16 feet wide. Based on the matrix and coordination with the City, it was determined that Path 1 at 12 feet wide is the preferred alternative, avoiding the gravel road leading to the pump station. The entrance aligns with the culvert, minimizing mangrove impacts. It is the most direct path minimizing seagrass impacts. However, the northern portion of this path is within the RPZ.

3D conceptual renderings of the chosen design path were prepared. The conceptual design is 12 feet wide and a minimum of five feet above the mean high water line, NAVD-88. The north entrance ramp was designed to be “T” shaped and approximately five feet wide and to be placed on the shoulder of Government Road. Additionally, the boardwalk will have a grated meshing providing at least 42 percent light transmissivity to underlying benthic resources.

These design measures meet as closely as possible those specified for locating piling-supported structures over protected resources specified in the Construction Guidelines in Florida for Minor Piling-Supported Structures Constructed in or over Submerged Aquatic Vegetation (SAV), Marsh or Mangrove Habitat U.S. Army Corps of Engineers/National Marine Fisheries Service, November 2017.

A US Army Corps of Engineers Section 404 dredge and fill permit for the discharge of fill material into the water of the US is anticipated, along with a South Florida Water Management Environmental Resource Permit for dredge and fill activities. The required mitigation will be determined after the final design is complete.

It is anticipated that the preferred alternative should address federal and state permitting requirements, and the consulting team recommends proceeding with the full design, permitting, and construction of this project.

Once constructed, the impact of the project on the overall safety of children, pedestrians and cyclists will increase with improved journey experience for all users.

This project helps the City of Key West move towards its goals of a Car-Free Key West - a city initiative to make it easier for residents and visitors to bike, walk and use public transportation.