Congress has taken another step toward restoring the flow of water through the Everglades by authorizing construction of 5.5 more miles of bridge along the Tamiami Trail, but stopped short of providing the $330 million currently estimated to get the job done.

The authorization was contained in the 2012 Consolidated Appropriations Act passed by Congress last week. While Sen. Bill Nelson, one of the sponsors of the language, has hailed its passage as bipartisan proof that Congress wants to see the River of Grass restored.

However, he also acknowledged that the country's current fiscal fitness could make it difficult to obtain the necessary funding to build those 5.5 miles of bridges.

Two years ago construction began on 1 mile of bridge along the highway. The work is seen as vital to restoring water flows through the Everglades to levels not seen in decades.

According to Everglades National Park officials, "removing as many barriers to flow as possible—roads, levees, canals, etc.—has become a mantra of the larger restoration effort, and resolving the deleterious impacts of Tamiami Trail is seen as critical to securing the long-term health of Everglades National Park."

The construction of the Tamiami Trail in 1928 blocked those natural water flows.  The Trail—a lengthy east-west roadway that crosses Florida—effectively severs the southern Everglades from the flow of water farther north.

"As a consequence, vast areas of Everglades National Park south of Tamiami Trail now suffer a chronic thirst that manifests itself in the form of frequent droughts, severe wildfires, and changes to the biologic community," says Larry Perez, who works in the Park Service's South Florida Natural Resources Center.

Coupled with recommended road improvements, the bridging along the highway "would allow managers to restore more natural flow patterns to Northeast Shark River Slough—a historic flow way that remains unnaturally dry," said Mr. Perez.

"Taking more than a decade, construction of the original Tamiami Trail was a lengthy and expensive effort," he notes. "At the time of its completion, however, the Tamiami Trail was regarded as a marvel of modern engineering and a testament to human ingenuity.