The Tamiami Trail Modifications: Next Steps Project

Above: The Tamiami Trail look- Eliminating Barriers To Water Flow. The increased foraging success for wading birds. ing east, with the Water Con- Tamiami Trail (U.S. Highway 41) has long servation Areas to the north, been recognized as one of the primary bar- Additional Bridging For The Trail. The and Everglades National Park LRR Plan is acknowledged as only a first to the south. (NPS photo) riers to flow of water through the ecosys- tem. step in the modifications to Tamiami Trail Inset: A common resident of needed for full restoration of natural water the Everglades: the American The need to eliminate barriers to overland conditions in Everglades National Park. Alligator flow of water in the Everglades is consid- ered one of the indisputable tenets of resto- In recognition of this, the 2009 Omnibus ration. Much scientific information amassed Appropriations Act directed the Depart- in recent decades reinforces the importance ment of the Interior (DOI) and the National of removing these barriers to water flow in Park Service (NPS) to evaluate the feasibil- order to restore natural marsh connectivity. ity of additional bridging for the Tamiami Trail necessary to improve the ecological In 2009, Congress authorized implementa- connectivity within the remaining natural tion of the plan selected in the 2008 Modi- Everglades, including Everglades National Mega-Project* Profile: fied Water Deliveries to Everglades National Park and the State of Florida Water Conser- The Tamiami Trail Modifi- Park, Tamiami Trail Modifications, Limited vation Areas. cations: Next Steps Project Reevaluation Report (LRR). The Act further directed that the evaluation Estimated cost: $285 million The 2008 LRR plan consists of a one-mile recommend a plan to achieve more natural (preliminary 2010 estimate) bridge and road improvements to allow the water flow and habitat restoration within increase in water levels in the adjacent canal the Everglades. The NPS initiated a study to be raised from the current 7.5 feet to 8.5 that culminated in a Final Environmental Percentage of SER’s FLTP An- feet. The LRR plan would improve potential Impact Statement (FEIS) for the Tamiami nual Allotment: 833% marsh connectivity, reduce sharp changes Trail Modifications: Next Steps Project. in water velocity, and improve rainy season Percentage of NPS FLTP depths and durations. Analysis. The NPS initiated an analysis to Annual Allotment: 119% determine how much additional bridging In addition, these modifications will im- was needed, and the associated benefits prove the ridge and slough landscape and and impacts with six alternatives that were fish productivity, which could result in evaluated. The analysis looked at eight factors: marsh connectivity, marsh water water depths and flooding durations that are velocity, re-connection of the ridge and critical to the survival of many fish and wild- slough landscape, vehicular wildlife mortal- life species, including the federally endan- ity, preservation of cultural resources, and gered Wood Stork, Everglade Snail Kite, and wetland loss. There was a strong positive Cape Sable Seaside Sparrow, and state listed correlation between the amount of bridge Roseate Spoonbill. span and the benefits provided, culminat- ing in the selection of Alternative 6E as the Next Steps Project – Design and Construc- preferred alternative. tion. The National Park Service has devel- oped a three-phased approach for imple- In December 2011, Con- mentation of the Tamiami Trail Modification gress passed the Con- Next Steps project based on maximizing solidated Appropriations early benefits to the park, reducing costs, Act of 2012, which au- and ensuring compatibility with other resto- thorized construction of ration projects in the Everglades. the preferred alternative: the construction of four The FEIS for this project determined that bridges with a combined construction of the 2.6-mile bridge located length of 5.5 miles. In in the westernmost portion of the 10.7-mile combination with the corridor would provide greater environ- 1-mile bridge, currently mental benefit per mile. Therefore, Phase under construction, these 1 consists of the westernmost bridge, with bridges will total 6.5 miles decreasing priority moving east along the of bridges within the 10.7- 10.7-mile corridor. mile Tamiami Trail cor- The design-build package for Phase 1 should ridor. be ready by June 2014 to award a construc- This level of bridging will tion contract by late September 2014, depen- eliminate historical hydro- dent upon available funding. logic constraints and allow The eastern bridge approach of the 2.6- Top: The Everglade Snail for more natural sheet flow mile bridge will be located just west of the Kite, one of the endangered patterns, improving ecological conditions Airboat Association, and the western bridge species that will be helped throughout much of the southern Everglades, approach will begin 1/2-mile east of the by the Tamiami Trail project. including the Water Conservation Areas and (NPS photo) Osceola Camp. Everglades National Park. Bottom: Artist’s rendition The bridge would be constructed approxi- showing the proposed 2.6- In addition, the remaining 5.2 miles of road- mately 50 feet south of the centerline of the mile bridge on the Tamiami way in the 10.7-mile corridor of the Tamiami Trail. (NPS graphic) existing roadway to maintain motor vehicle Trail will be raised to allow water level in- traffic during bridge construction. * Mega Projects: The NPS creases in the adjacent L-29 Canal consistent transportation system is with the 9.7-foot design high water. This level supported, in part, by funds of road elevation precludes the need for any from the Federal Lands Transportation Program future modifications to the highway corri- (FLTP). Currently, the NPS dor when full restoration of the Everglades is authorized an annual is achieved through the addition of projects budget of $268 million from supplying sufficient flow of clean water. the FLTP. These funds are ap- portioned by formula among The increased water volumes and flow dis- the seven NPS Regions. Most tributions will reestablish the seasonal water of these funds are used for “transportation asset depths and flooding durations that are criti- management” – that is, to cal to the survival of fish and wildlife species, pay for the work required to including many endangered species. keep existing assets in good condition. There are some Future Funding. If the Tamiami Trail Modi- projects, such as a major fications: Next Steps project is funded and bridge repair or ship replace- implemented in conjunction with other ment, that require a much larger amount of funding planned restoration projects, ecological con- than is available on an an- nectivity between the marshes located in the nual basis to a Water Conservation Areas and Everglades Region. These we call “Mega National Park will be substantially improved. Projects.” The NPS is pursu- ing strategies to fund these The increased water volumes and improved projects. flow distributions will reestablish seasonal

Last Updated 2016 April