Businesses and job-seekers throughout the region are expected to benefit from a burst of ship traffic, which would set off economic ripples across the state. The spillover effect could also help bring commerce and tourism to shallower seaports such as Port Canaveral and the Port of Palm Beach.

"We've got the momentum going again," U.S. Rep. Lois Frankel, D-West Palm Beach, said on Tuesday.

"This will allow heavier ships to come in with much more freight," she said. "It's about a $500 million economic impact, which is far more than what it's going to cost. It's about jobs, jobs and more jobs."

The breakthrough, following 17 years of frustrated attempts to get federal dredging money, came when Frankel and fellow Florida members persuaded congressional leaders to amend a water-projects bill that is expected to pass the House on Wednesday. The amendment would allow Broward County to eventually get reimbursed for about $4 million spent to get the project started next year so it could be completed by about 2017, two years after a widened Panama Canal will open for business.

"It's a huge economic opportunity," Port Director Steven Cernak said on a lobbying trip to Washington last month. Broward officials and business leaders also made port expansion their top priority when making the rounds on Capitol Hill during another trip two weeks ago.

The expansion, which would deepen the port's waterways from 42 feet to 50 feet, is projected to create 5,862 short-term construction jobs, 1,491 permanent local jobs and tens of thousands of spinoff jobs statewide.

The project is expected to cost $330 million, with Uncle Sam paying $160 million and Broward, the state and the port paying the rest. Gov. Rick Scott last week urged the state Legislature to approve $14.7 million for the port to widen its turning area for cargo ships.

The port project had been left out of the House water bill because federal agencies are still arguing about the most effective way to compensate for damage to coral beds, seagrass and mangroves. The dispute stems from 17 years of study. As a result, the port project has not been cleared for construction by the Army Corps of Engineers.

But Frankel and others persuaded Chairman Bill Shuster, R-Pa., to amend the bill to make it possible for a local government to pay upfront and get partially reimbursed when the Corps approves the project and Congress passes another water bill.