About 40,000 homes have been damaged by floods caused by heavy rains, and 20,000 people have been rescued.
In Livingston Parish, home to 138,000 people, officials estimate that 75% of homes have been completely destroyed.
Residents returning to their homes are finding standing water, mould, and pest infestations, while the threat of further flooding and rainfall remains.
David Key arrived at his house in Prairieville by boat this morning to find five inches (12.7 cm) of "muddy nasty bayou water".
"I'm not going to lie, I cried uncontrollably," he said. "But you have to push forward and make it through. Like everybody says, you still have your family."
The National Weather Service is predicting that the chance of thunderstorms will continue in the region throughout the week, with temperatures expected to reach 32C (92F).
At an afternoon press conference in Baton Rouge, Louisiana Governor John Bel Edwards updated the death toll to eight people, and described how emergency crews are continuing with rescues.
"Nobody is going to be forgotten and we're going work around the clock," Mr Edwards said, calling the disaster a "historic flooding event".
"It's unprecedented," he told reporters. "We understand that there are a lot of people who are suffering."
Emergency crews are checking washed away cars for the bodies of motorists who may have become trapped inside.
Floodwaters have been receding today in most of the effected areas, however water levels are rising in the southern parts of the state as the excess water washes downriver and out to sea.
Residents are beginning to return to their flooded homes, even as more rains are expected in the state of Louisiana.