Lake Marion’s water levels have plunged by more than four feet over the past few days as Santee Cooper, South Carolina’s water and power utility, rushes to make room for floodwaters from North Carolina.

Helene made landfall last Thursday as a Category 4 hurricane, with maximum sustained winds of around 140 miles per hour near Perry, Florida, in the state’s Big Bend region.

The storm brought fatalities across several southern and southeastern states, with storm surges, devastating winds, and torrential rain that threatened several dams and flooded Asheville, North Carolina.

More than 100 people were killed by the storm, the Associated Press reported. Days later, damage and devastation remain, and North Carolina floodwaters are coming to South Carolina.

On Monday evening, Santee Cooper warned Lake Marion boaters that the lake’s waters may exhibit sudden changes over the next few days.

“Boaters beware: We’re drawing down the lakes to make room for a wall of water coming from NC,” the utility posted on X, formerly Twitter. “Lake water will fall and rise in the next few days. If you must be in a boat, use extreme caution, avoid the Spillway, and watch for rapid water currents.”

A press release from the utility said that “near-historic water flows” were expected to make their way downstream from the North Carolina flooding, amounting to inflows of 2 million gallons per second into Lake Marion. To make room for the water, the utility began lowering the lake’s volume by spilling water from the dam last week.

On September 27, Lake Marion’s water levels were nearly 75 feet. By Tuesday morning, they had dropped to just over 70 feet, a steep plunge compared to average water levels over the past few years. Water levels have mostly ranged from 73 to 76 feet during that time.

The press release assured South Carolina residents that the utility’s dams are secure and not at risk of failure. Last week, Hurricane Helene’s torrential rainfall stressed several dams in North Carolina and Tennessee to the point of imminent failure.

Officials plan to spill water from Lake Marion at a rate of nearly 1 million gallons per second beginning on Tuesday to continue allowing room for the excess water.

Newsweek reached out to Santee Cooper via email for comment.

Although the dam is secure, Santee Cooper warned that flooding may occur in the Santee River floodplain by Thursday or Friday.

“This is a significant spill, and flooding should be expected in the same areas in Georgetown County as experienced in 2015 and 2020, when the utility also conducted major spills,” the press release said. “Flooding will be more significant in areas closer to U.S. Highway 17. The Santee Cooper team is working with local and state authorities to manage any related issues.”

Spilling will continue until further notice.