Four years ago, when the waters from Doubloon Bayou sloshed into Lew Arthur's garage, he was told that it was one of those freaks of nature that happen once every 100 years.

Three years ago, when floods did $10,000 in damage to his house, he was told that it was something that would happen once every 40 years.

Arthur's house has been flooded twice this week, and, while he said he doesn't know what the experts will say this time, he's inclined to be skeptical. The changing topography of the area, he figured, is changing the odds.

"Every time you have a new subdivision or a new shopping center around here, it's going to get worse," he predicted.

"Something's happening," agreed a neighbor, Jerry Seale.

The two were chatting in Seale's driveway this morning while they waited for the water to recede into the bayou and then into the West Pearl River some four miles away.

Across the South today, the worst appeared to be over in the historic Dixie floods that killed 13 people, displaced more than 52,000 and left an estimated $625 million in damage.

By midmorning, according to the National Weather Service station here, the muddy floodwaters were diminishing at about 6 inches a day from a high point of nearly 22 feet. Meteorologist Jim Belville said "it should get out of all the houses" by Thursday.

Lest anyone think that this is a slow drop, Belville cautioned that a mighty volume of water was involved. There was an average of 11.2 inches of rain last week over the entire 5,000 square miles around the Pearl River.

"At the height of the flood here," Belville said, "the amount of water moving down the Pearl was equivalent to the Mississippi River in low flow."

Over in Frenchmen's Estates, Seale, the first homeowner to move into the $120,000-and-up subdivision 10 years ago, was a bit luckier than Arthur. The flood waters damaged Seale's back-yard pool, but they stopped "just a whisper" short of the floor level of his house.

An industrial lubricant salesman, Arthur said flash flooding from last Thursday's 10-inch rain sent about 4 inches into his house. All of it had drained away by Friday, but Sunday's overflowing of the Pearl put another foot of water in the brick-and-frame home. He expects at least another $10,000 in damage, and months of hassling with contractors to set things right again.

"We have flood insurance," Arthur said. "In 1980, they covered just about everything over the $500 deductibles. We had to have new carpets, new baseboards, new wallboards to a height of about four feet."

Meanwhile, Arthur said, with the voice of experience, "You just live upstairs. You don't get your kitchen in order."

Arthur and Seale said they have overheard some neighbors talking about "getting the hell out of here." But it's lovely country, Arthur said, and new buyers always will be moving in.

"My wife's in real estate," he said, "and she's sold three houses that had been flooded before. She told the people about it, but they all said, 'we like the house,' and they bought them anyway . . . . It's almost like when you go off to war. You never think it's going to happen to you."

A few minutes later, about a half mile down the road, a gray sedan driving along Military Road approached a pile of sandbags blocking the highway. A few yards from the barricade was a sign that read "Quail Ridge--Homes over $100,000--Entrance."

The subdivision was deep in water, but behind the wheel of the gray car was a saleswoman with a "Century 21" badge showing a client the neighborhood. The prospective buyer, Ginny Kamath, was not at all perplexed. She and her husband, a doctor from Anchorage, are moving to Slidell.

"We like this area," she said. Besides, "I want to see where the high land is."