Lake Wateree rose to 106 feet on Saturday, its highest level since Hurricane Hugo at 107 feet in 1989, according to the National Weather Service.
The organization tweeted Saturday that the level should remain steady before making a decline.
Rain during Thursday's severe weather increased water levels in Columbia. The Congaree River rose to 28 feet and has flooded the surrounding area.
A cold front is responsible for triggering storms. The severe weather outbreak on Thursday included risk of winds, flash floods and tornadoes.