CHARLESTON, S.C. — The South Carolina Supreme Court on Monday agreed to hear a dispute over a permit for a $600 million deepening of the Savannah River shipping channel.

Proponents say the deepening is needed so Georgia ports can handle larger ships that will be calling when the Panama Canal is widened in two years.

A lawsuit filed last month contends that the water quality certification approved by the board of the South Carolina Department of Health and Environmental Control is illegal. That’s because five years ago, lawmakers gave authority over river dredging decisions to the state’s Savannah River Maritime Commission, the lawsuit says.

The suit was brought by the Southern Environmental Law Center on behalf of the Savannah Riverkeeper, based in Augusta, the South Carolina Coastal Conservation League, the South Carolina Wildlife Federation and the Conservation Voters of South Carolina.

The groups contend that deepening the channel will harm wetlands on the South Carolina side of the river, including the Savannah National Wildlife Refuge and the creatures that live there.

In a brief order issued Monday, the high court agreed to take original jurisdiction in the case; that means the justices will hear arguments without the case first winding through the lower courts. DHEC officials said earlier they did not oppose the case going straight to the high court. The order sets out a schedule for filing papers in the case.

“We are pleased the Court is moving with dispatch to resolve whether the DHEC Board overstepped its authority,” said Blan Holman, an attorney with the Southern Environmental Law Center.

Besides environmental concerns, South Carolina lawmakers say the permit gives an advantage to the Georgia ports that are in fierce competition for business with Charleston, where a study of deepening the Charleston Harbor shipping channel is also under way.

Earlier this year, lawmakers passed a law retroactively suspending DHEC’s ability to make dredging decisions involving the river, saying they belong with the maritime commission. Haley vetoed the law, only to be overridden by the General Assembly with all but one lawmaker in both chambers voting to override.