NEW ORLEANS (AP) Construction on a $629 million replacement to the hurricane-damaged Twin Spans bridges connecting Orleans and St. Tammany Parish will begin no later than July, state highway department officials said.

The project, which is the most expensive public contract in Louisiana history, was awarded to Boh Brothers Construction, said Mark Lambert, a spokesman of the Louisiana Department of Transportation.

Construction is expected to take three years, Lambert said. Funding is coming from emergency federal storm aid.

Hurricane Katrina’s tidal surge ripped Interstate 10’s twin spans of concrete and tossed some of them into Lake Pontchartrain.

Other sections were shifted out of place by as much as 5 ft. Repair crews cannibalized undamaged spans from the westbound bridge to patch the eastbound bridge, which was converted temporarily to two-way traffic and opened Oct. 14. That left approximately 1 mi. of the westbound roadway missing.

The second temporary span was opened to traffic on Jan. 7.

The new bridges will be made of concrete, except for a high-rise section, which will likely be built with steel, Lambert said. The high-rise section will be much higher than the current span.

Pilings are already being driven for the new spans, Lambert said.

The current bridge will be demolished once the new span is complete.