This once-sleepy university town has gotten so big so fast that it needs a new city hall. And the town's bean-counters have come up with a razzle-dazzle way to build it.

First, the city is going to lease a chunk of prime downtown real estate to a developer. Then, the developer will put up a city hall/hotel/shopping mall/office building/parking garage complex. Then he'll lease the new city hall back to the city.

To all the laid-back 1960s-types who flocked to Austin over the years thinking it was an outlaw corner of the Sun Belt too smart to put up with boom-town hassles, the project speaks volumes about what's become of their little hideaway. Developers are riding so tall in the saddle here, they're about to own the very seat of city government.

Paradoxically, the "no vacancy" bumper stickers and the "no" votes on growth-related bond issues seem to have only fired the curiosity of a nation of migrant yuppies.

They come in droves. Austin is growing faster than Houston or Dallas, faster than just about any city in the country -- and faster than it can handle.

"They're literally going to run me out of town," mourned Kaye Northcutt, a free-lance writer who, like so many University of Texas graduates, hung around after college for the inexpensive small-town ambience, the vibrant music, the hills and lakes, the faintly anti-establishment life style (until a few years ago, the women went topless at the city's sparkling spring-fed public swimming hole) and the un-Texas-like aspirations to intellectualism.

"It's been said that Austin is the only city in Texas that thinks to ask, 'If you're so rich, why aren't you smart?' " Northcutt added. "I'm afraid we're in the process of turning that around."

Each week, it seems, another high-tech firm sets up shop along a stretch of Austin highway known as Silicon Gulch, another tweedy men's clothing store is cutting a ribbon downtown, and another land developer has just quintupled his money by "flipping" a piece of property three times in no time.

Some people think it's wonderful. Part of what's happened is that the '84 Volvo crowd is starting to outnumber the '64 Volvo crowd, and there's a constituency for growth for the first time in Austin's history.

In the old days, the economic base consisted of underpaid professors and state bureacrats who'd sniff at soulless, hell-for-leather boom towns like Houston or Dallas.

But last year, the Microelectronics and Computer Technology Corp. (MCC) chose Austin over 57 cities as the home for its research consortium of 19 leading computer companies -- vastly accelerating the migration of high-tech firms that had begun a decade earlier. To help woo them, the University of Texas has created 36 professorships in engineering and the sciences; each is endowed with $1 million.

So there's money floating around -- and money means lawyers, land developers and dealmakers. To these slick new booster-types, the hot new civic buzz number is 1 million -- the area's projected population by the year 2000. Right now, Austin has just over 400,000 people and the metropolitan area 625,000.

"Austin is a much better place to live in because of the growth," said Pike Powers, a prominent local lawyer and former executive assistant to Gov. Mark White (D). He is heading a citizens' task force that has just recommended that Austin certify its new aspirations in the time-honored American way: by building an oversized new airport.

In some senses, Powers is right. Growth is about to provide Austin with a new arts museum downtown, and a bagel can be found almost as easily as a chicken-fried steak.

But there has also been, as the bean-counters would say, a downside.

In a city full of brainy planners, Austin has somehow gotten itself into a fix where it has to truck tons of raw sewage each day from one end of town to the other because it can't treat the stuff any other way.

It's gotten itself into a fix where it has a waiting list of nearly 1,000 people who can't move into the homes they've already bought, because the city has been forced to ration water and sewage hookups.

It's gotten itself into a fix where, when it rains too much, the sewage-holding ponds are in danger of overflowing, and when it rains too little, as it did last summer, it has to ration the drinking water.

It's gotten itself into a fix where the ecologically sensitive limestone hills of live oak and scrub cedar west of town are now the hottest spots for commercial development -- which is exactly what city councils for the past decade have tried to prevent. But when 3M announced it was building a major research facility in the hills this year, the council members heard about it like everyone else -- in the newspaper.

"The commercial land developers are dictating where growth occurs in this town," fumed Roger Duncan, an environmentalist on the city council.

It's gotten itself into a fix where a city possessed of more natural beauty that any in Texas has managed to pockmark itself with some of the ugliest suburban sprawl on God's green earth and some of the most aggravating traffic congestion.

On top of all that, singer Willie Nelson's old haunt, the Armadillo World Headquarters, has been demolished to make way for an IBM building, and skyrocketing rents have forced some of the jazz and folk hangouts out of business.

"A few weeks ago, I went into a restaurant downtown on a Friday night with an attorney for the state and a UT professor, and we all had on our Austin uniforms -- blue jeans," recalled Northcutt. "When we got inside, for the first time I can remember in Austin, I felt underdressed. We all sort of looked at each other like, 'What should we do?' The attorney said we had to stay; it was a matter of principle. He was a refugee from Dallas who'd come here to escape that sort of stuff."

For years, Austin tried to keep "that sort of stuff" at bay. The strategy was simple. Every time the city council proposed a bond issue for a new water or sewage treatment plant, the voters turned it down. No municipal services, they figured, would mean no growth.

They were wrong. Austin grew anyway, in part because Texas law retains its frontier antipathy to land-use restrictions, and it has limited Austin's ability to limit its growth.

In Texas, a developer can establish something known as a Municipal Utility District (MUD) in any area not serviced by an existing water and sewage system. In effect, MUDs allow developers to go into the utility business, getting tax-free bonds to build water and sewer lines into their subdivisions, then charging their customers for the lines in the price of their houses.

"MUDs have been a huge boon to us," said lawyer Ed Wendler Sr., a lifelong Austin resident who has helped his clients set up two dozen MUDs here. "We've gotten spoiled by them."

The developers weren't careful about ensuring that there was enough water and sewage treatment plants to service all the subdivisions they were building. The result has been a nightmarish year here of rationed water, trucked sewage and tearful newcomers complaining to the city council that they can't move into the houses they've already bought.

It's a small wonder that people think the quality of life is on the way down.

In a poll taken this summer by a University of Texas professor, 1,433 Austin voters were asked to rate the quality of life here today and five years ago, and to project how it will be five years from now. On a scale of 1 to 10, today was ranked 7.2, five years ago was 7.7 and five years from now ranked 6.0.

"Any city that tries to play catch-up ball with growth is in big trouble," said Dowell Myers, an assistant professor of community and regional planning at University of Texas School of Architecture, who supervised the poll.

That's what Austin is doing now. This fall, voters approved a $955 million bond issue for new roads and municipal services. It was the largest ever passed here and the first in more than a decade that did not run into opposition from the no-growth forces.

Indeed, growth is a given now; the only question left is whether Austin has the wit and will to manage it in a way that protects the environment and life style.

There is enough environmental sensitivity among the business community here that the development in the western hills will be done with care; just to make sure, the council is drafting a stiff new set of ordinances.

In the meantime, the voters are expected to increase the sales tax by a penny in January to finance an improved public transit system.

"Austin still has a chance to do it right," said Powers. "We don't want to wake up in the year 2000, completely behind the eight-ball, like a Houston, and realize our quality of life has slipped away."