It has been more than five years since the muddy waters of Four Mile Run last surged over their banks, terrorizing residents and inflicting millions of dollars in damage on Arlandria, a quiet, low-income neighborhood in northern Alexandria.

A $58 million Army Corps of Engineers flood project widened, straightened and subdued Four Mile Run and put an end to the flooding that regularly deluged the neighborhood. The mud, rats, snakes and sewage the waters always left behind are things of the past. But with the receding of the waters, something else is on the rise in Arlandria: real estate prices.

"Look, it's a mile from Crystal City, a mile and a half from the airport and two miles from the Pentagon," says one developer. "How could it miss?"

"There's something going on," says Helen Hovermale, an Arlandria resident since 1951. "There are an awful lot of houses boarded up all around here . . . . I've lived through seven major floods and I've jacked my house up with wood. I won't leave. They'll have to carry me."

So far, little change is visible in Arlandria. The streets still are quiet, the wind still blows trash and debris down Mount Vernon Avenue. Many of the low-income families that grew accustomed to dragging valuables upstairs during the storms are still here.

But change more powerful than rushing water is certain, because Arlandria is the last Alexandria neighborhood where homes can be had for less than $70,000. By the 1960s, building upstream along Four Mile Run had caused flooding, and the transformation of Arlandria from a neat middle-class neighborhood to a lower-income area had begun. With the flooding stopped, the process has reversed. The indicators are unmistakable:

Homes in Arlandria that sold for an average of $30,000 in 1975, now routinely bring $60,000 and have sold for as much as $79,000. "Old Town is pretty much capitalized," says city planner Van Slaymaker. "Not Arlandria. Values there will continue to go up."

The percentage of absentee-owned properties increased 20 percent from 1973 to 1977, leaving72 percent of the neighborhood's homes absentee-owned.

The condominium craze hit Arlandria with the recent conversion of Auburn Village apartments. The Arlandria Court apartment complex recently was sold to a corporation, and its residents are worried that the new landscaping around the building means that it, too, soon will be converted.

Commercial property sales are on the rise. The Hertz Co. purchased five acres for $3.2 million: $15 a square foot, or $8 a square foot more than the land's assessed value. Other commercial properties have sold at prices $100,000 to $150,000 above their assessed value.

Alexandria planners have drawn up a "revitalization plan" for the Mount Vernon Avenue strip. The plan envisions new commercial development along the avenue, development that will increase surrounding property values.

For all of these reasons Arlandria residents, many of whom hold low-paying blue-collar jobs or rely on public assistance, wonder whether the new Arlandria will have a place for them.

"It's not easy for anyone right now," says an Alexandria city assessor.

Arlandria, which sits west of the railroad tracks, east of West Glebe Road and south of the Arlington County line, has changed greatly since the 1950s and early '60s.

In the 1950s, the GS-8s and Army personnel who bought houses there paid an average of $11,000. They shopped at the Arlandria Shopping Center, sent their children to the Mount Vernon movie theater for the Saturday matinee and kept busy on weekends planting rose bushes and azaleas and putting up picket fences. If the weather was right, they also kept busy swatting mosquitoes, for much of the 40-acre Four Mile Run Park that has been filled in today then was swamp.

"It was so pretty then," Hovermale says.

By the 1960s, however, the flooding had begun. Rainwater from more and more developed land upstream washed into Four Mile Run and its tributaries from as far away as Falls Church. Two ducts built in the last century to handle the water that funneled down under the yards of the Richmond, Frederickburg & Potomac Railroad along Rte. 1 were inadequate. When the rushing water turned back from the pipes under the railroad yard, the effect, say city firemen who remember the floods, was like a tidal wave. During heavy rains, Arlandria often was one big bathtub.

The neighborhood gradually changed from white middle class to a mix of black and white lower-income families. And then, in 1979, the city condemned the rundown Shirley Duke apartment complex and relocated many tenants in Arlandria. Longtime Arlandria residents say that was a blow from which the neighborhood has not yet recovered.

"Shirley Duke was nothing more than a flophouse when it was condemned," says City Council member James Moran, "and many of the people who came to Arlandria brought their problems with them." Those problems included lawns filled with trash, drug dealing, street fights, vandalism and purse snatching.

"I love to walk," says one elderly woman on Edison Street, "but I hardly risk it anymore."

One bright spot has been a city housing program that will allow at least 23 low-income families to purchase renovated, three-bedroom, brick townhouses in the neighborhood for $44,000, at mortgage rates designed to keep monthly payments below $400.

"It makes me feel so good," says one woman who goes to settlement on her house in a few days. "I feel like I've accomplished something, after all these years of struggling."

"It means that I won't be making other people rich," says Louise Drayton, who with her husband, Friedman, and their seven children will buy a house under the program.

But many more Arlandria families either did not have the down payment or $16,500-a-year minimum income needed to qualify for the program, or were rejected because the two adults in the household were unmarried, says Sally Carter, a city housing official who has helped organize the program.

A key to revitalizing and increasing the value of Arlandria property, say city planners, is the new Arlandria shopping center on Mount Vernon Avenue. It now boasts a liquor store, grocery, and a shoe store, but a large space on one end sits empty. The center's owners say that high interest rates are holding them back.

"It's been slow and frustrating," says Ed Alfriend, one of the owners. "We can't demand high rents until the place is upgraded, and we can't do that until we can get some money at a reasonable rate."

Another obstacle is convincing retailers that a neighborhood of lower-income families can support the shopping center.

"It certainly will never be another Old Town," says city planner Van Slaymaker. "But that's okay. I don't think anyone wants to see that."

So for the moment, Mount Vernon Avenue remains much the same. Dotted with beauty parlors, laundries and shoe repair shops, the neighborhood shows more reminders of old days than the new. The Mount Vernon movie theater was torn down a while ago, but its silvery marquee remains.

"I remember when the kids used to line up around the block on Saturday afternoons," says Hovermale.

Short-order cooks at the Waffle Shop , a 31-year-old restaurant, still dish up waffles and a dazzling variety of fare from behind the small, Formica countertop -- even flood waters that floated coffee cups out the door couldn't change that. But it, too, has been touched recently by the impending changes.

"A-rabs," a waitress confides, bought the property two years ago. The new owners have changed little of the Waffle Shop's warm, grimy splendor, including the front awning that spells the restaurant's name as the Wafle Shop.

The waitresses still greet regulars by plunking down a napkin and asking, "Want anything different today?" Most everyone who walks in the door has a nickname. A man named Clarence is known as "One, One and One," for his usual order of one egg, one sausage, one piece of toast. At the Waffle Shop, such a sparing diet is unwelcome.

"You don't eat like that over there," the cook tells One, One and One, pointing across the street to McDonald's, the Waffle Shop's modern competition.

"How about a knuckle sandwich?" the waitress asks Clarence, who smiles and calmly continues to fork down his breafast. He obviously has heard that kind of neighborhood boosterism before.