Tamiami Trail

An aerial view of Tamiami Trail (US Highway 41); the road acts as a dam in the Everglades, blocking the natural flow of water from north to south. Lori Oberhofer/Everglades National Park

The Past

One of the essentials to restoring the River of Grass is the removal of key dams. One of the most prominent “dams” is the Tamiami Trail. The Tamiami Trail was hailed as a great feat of human engineering when it opened in 1928. Pushing south from Tampa along the western edge of what is now called the Big Cypress Swamp to Naples, the two-lane, 275-mile road sliced east through the swampy Everglades to its Miami terminus.

The 13-year project cost $8 million. When the state of Florida ran out of money, the 65-mile east-west section was completed with the help of advertising mogul Barron Collier, who had grand plans to open southwest Florida to development. In exchange for his construction cash, a county was named for him.

“It was a project of profound and unintended consequences,” says Dr. Tom Van Lent, senior scientist, Everglades Foundation. The feat of roadway engineering disrupted Mother Nature’s own marvel of hydrology–the Everglades–the shallow, 70-mile-wide River of Grass that flows slowly south, starting in the Kissimmee River area just above Lake Okeechobee to Florida Bay.  When the road was built, if water in the Everglades was high, the road was simply closed. Today, with modern traffic and high speeds, water managers keep the water levels around the road low to maintain traffic. “It acts just like a dam across the Everglades,” Van Lent says.

The area south of the road, which is Everglades National Park, receives only a portion of its annual southerly water flow, and most of the water the Park does receive is not in the historical pathway.

The Present

Tamiami Trail spurred the transformation of the ecology of the southern Everglades. The reduced water flow damaged fish reproduction, wading-bird nesting sites and the habitats of other endangered species unique to the Everglades. The health and quantity of natural vegetation such as sawgrass marshes and tree islands were compromised. Without southerly-flowing fresh water, salt water seeps further inland, upsetting nature’s delicate balance of and endangering freshwater aquifer wells. Supporters of Everglades restoration agree with the scientific evidence that proves the Tamiami Trail has to be modified to provide the best opportunity for the Everglades’ long-term survival. “If we want to restore the River of Grass, we have to take out the dams,” says Van Lent.

Photo by Lori Oberhofer/Everglades National Park

The Project

In 2005, The U.S. Army Corps of Engineers devised a plan to erect an Everglades Skyway – an 11-mile bridge to replace part of the road just west of Miami. But, Congress eventually allocated enough funds to construct a one-mile bridge in 2008. After the preconstruction and design phase of the one-mile bridge plan was complete, an $81 million contract was approved in 2008 and groundbreaking took place in December 2009. The first mile of bridging is expected to be complete in December of 2013. 

In addition to the bridge construction, plans are being evaluated for an additional series of bridges and/or elevations of the Tamiami Trail to facilitate additional water flow. This effort will be critical to the recovery of the Everglades and Florida Bay. Everglades Foundation scientists see the one-mile bridge as a critical first step to improve water flow through the barrier. “Our scientists will be monitoring the impact of improved water flow along Tamiami Trail,” says Van Lent. By looking at the where changes occur and the rate at which they occur will help inform future steps. That will help government agencies make enlightened decisions on restoration. 



The Future

The U.S. Department of the Interior’s National Park Service released a draft Environmental Impact Statement (EIS) in May 2010 that recommends an additional 5.5 miles of bridging on Tamiami Trail in addition to the one mile of bridging currently under construction to restore natural water flows to the Everglades.  The new bridging would create an opportunity to restore up to 100 percent of the historic volume and distribution of water that used to flow southward into Northeast Shark River Slough before the Trail was constructed. If completed, the additional bridging would eliminate the hydrologic constraints throughout much of the southern Everglades, including the Water Conservation Areas and Everglades National Park. For more information on the draft EIS visit:

The Tamiami Trail bridge is part of a larger effort to “de-compartmentalize” the Everglades to restore the natural flow of the River of Grass. While the Everglades will never be restored to its once pristine state, projects such as the Tamiami Trail bridge are part of a solution to allow the Everglades to benefit from free-flowing water which could revitalize plant and animal populations and sustain the water supply for South Florida’s human inhabitants. “We’re on a track to demonstrating really tangible results in the saga of Everglades restoration,” says Van Lent. “We’re putting a big hole in the dam.”

Tamiami Trail-Fact Sheet