WASHINGTON —Sen. Mary Landrieu has signed onto new, bipartisan legislation to protect the waterways and ports in Louisiana and the rest of the nation.

The New Harbor Maintenance Act being sponsored by Landrieu, D-La., and 28 other original Senate co-sponsors joins other efforts to protect the federal Harbor Maintenance Trust Fund.

The fund dedicated to river dredging and port improvement projects was allocated nearly $1.8 billion in the most recent funding cycle, but more than half of the fund is raided for other spending by Congress and the White House.

“This legislation is extremely important for the proper maintenance of Louisiana’s waterways, which serve as gateways to domestic and international trade,” Landrieu said in the announcement. “Even though Louisiana’s port system is the largest in the world and supports economic growth throughout the country, the waterways that serve these ports are not being adequately maintained. We need the Harbor Maintenance Act to ensure these funds are used as intended for our ports and waterways.”

The U.S. Army Corps of Engineers estimates that full channel dimensions at the nation’s busiest 59 ports — several of which are in Louisiana — are available less than 35 percent of the time.

The legislation is not the only effort ongoing to protect the fund.

Sens. Barbara Boxer, D-Calif., and David Vitter, R-La., who lead the Senate Environment and Public Works Committee, last week led a hearing titled “The Harbor Maintenance Trust Fund and the Need to Invest in the Nation’s Ports.”

Vitter and Boxer said they are planning on putting a measure into the 2013 Water Resources Development Act bill, which is expected to be filed in a few weeks, that would keep the trust fund from being raided and also add a provision that would allow excess funds to go straight to port authorities for some specified projects.

Such a measure is expected to resemble the Realize America’s Maritime Promise Act by Rep. Charles Boustany, R-Lafayette, which would keep lawmakers and the White House from reallocating from the fund.

A version of the RAMP Act became law last year but it was gutted behind closed doors by Congress with much weaker language that indicated funds from the $8 billion Harbor Maintenance Trust Fund “should” only go to dredging and ports efforts. As is always the case in legislation, the difference between “should” and “shall” is significant.