Officials are warning the public that as the rivers rise, it is imperative to stay out of the floodwaters.
Several rivers in the state are at moderate to major flood stages, with areas where homes and businesses have been impacted by the water. Most of those rivers have not reached their crest yet, and may not until Friday evening.
"Stay out of the flood waters," said Mississippi Department of Health Director of Health Protection Jim Craig. "It has septic-type products, raw sewage, industrial and agricultural chemicals. If you or your pets have contact with flood waters, wash thoroughly with soap and water."
Mississippi Emergency Management Agency Chief of Staff Bill Brown added that people should not try to drive through the flood waters, and they should keep their children out of them as well.
"The best thing to do is turn around, don't drown. Don't go in the flood waters, don't allow your children to go in the flood waters," he said.
Governor Phil Bryant recalled a Yazoo City child who was drowned earlier this week. Nine-year-old Petrauna Hudson was washed away while playing in the water outside her home. Her body was found a mile from her house.
"It may look calm on the surface, but the current beneath it could be moving swiftly and could be dangerous," he said.
National Weather Service Hydrologist Marty Pope said 15 rivers at moderate flood stage, things aren't great, but they could be a lot worse.
"The heaviest rain did not go up the main stem of the Pearl, but it did cause lots and lost of flash flooding," he said, adding that the Pearl River should reach 35.5 feet by Friday evening.
National Weather Service meteorologist Daniel Lamb said the level should hold there through much of Saturday before beginning to start falling on Sunday.
Jackson officials issued an alert on Wednesday to residents in certain areas that may be affected by flooding from the Pearl River and any of its tributaries.
These areas are likely to be affected by sanitary sewer overflows resulting from ground water and standing flood water overwhelming the sanitary sewer collection system and pump stations. Water in these flooded areas is likely to be contaminated with raw sewage, the release stated.
The city is currently under a $400 million federal consent decree with the Environmental Protection Agency, in part because the agency cited multiple instances of sewer overflows. One of the driving forces behind the successful push for the 1-cent sales tax was to raise funds to help pay the large tab with EPA.
The water will impact other municipalities in Hinds County as well, Lamb said.
"Water will start to get into some of the streets, especially on the northeast side of town, and farther downstream it will have impact on some residences around the Byram area, then on down toward Terry and that area," he said.
The flooding could drive animals to look for higher ground.
"We'd like to remind everyone you will likely see wildlife that has been displaced," said Mississippi Department of Wildlife, Fisheries and Parks Chief of Law Enforcement Steve Adcock. "Leave them alone, they're already stressed out, and as soon as the water goes down they'll return. This includes reptiles, and the best thing you can do is keep your distance."
It's hard to say how much water will actually impact each area, as the levels will be varied.
The Ross Barnett Reservoir is expected to flood over its banks a bit, but should only affect structures right on the water that usually flood when the water levels are high, Lamb said.
The Big Black River is also rising and will end up affecting thousands of acres of farmland.
"Folks have had to move cattle and that sort of thing because the river is rising," Lamb said. "The Big Black is still going up, so it will get worse for those folks."
The NWS has monitoring points along the Big Black at West, Bentonia, and Bovina.
Near Laurel, the Tallahala Creek reached major flood stage when it crested overnight, impacting structures on the east side of Laurel. Lamb said water levels are falling now on the Tallahala.
The Leaf River, which flows east of Collins down to Hattiesburg, is nearing its crest at moderate flood stage, Lamb said. It is expected to crest today around midday at 28 feet.
"Usually when we say moderate, we're talking about water impacting structures and that kind of thing," he said. "Based on some of the past floods that have occurred, that suggests there could be several homes that could be affected to the east of Collins."
There is also some minor flooding on the Yazoo River near Yazoo City.
Hopefully, though, the rain has stopped at least for the time being.
"It looks like it'll stay dry through the remainder of the week and into the weekend, and that allows the rivers to drop off," Lamb said.
On Sunday there is a slight chance of rain, with a better chance on Monday. Lamb said for most areas currently affected by the flooding, that will be a sufficient amount of time for the rivers to reach their typical stages again.
"Once we get into the early part of next week we'll keep an eye on it. It's hard to say if it will lead to additional flooding," Lamb said.
US 49 in Simpson County was closed for parts of Monday and Tuesday after heavy rains, and flooding and damage was reported in several counties around the state.
Clarion-Ledger staff writer Dustin Barnes contributed to this report.