Columbia, a town where everybody lived someplace else 11 years ago, is throwing itself a birthday party.

Columbia is 10 years old this month and awash with chauvinistic pride.And like any 10-year-old who gets to plan his own party, Columbia seems determined to have everything the big kids ever had for their own celebrations.

Does Baltimore have a city fair? Columbia is having one too. Do Midwestern towns have pot luck suppers, community picnics and sack races? Columbia is having them too. Does Boston have a marathon? Does the world have Olympics? Guess who's having them too.

The festivities, mostly fun and games, range from plaque presentations to introspective seminars. They began last weekend and won't end until midnight on the Fourth of July.

Columbia T-shirts, ties and other memorabilia are being sold at booths set up in the Mall and village centers. Banners festoon the lamp posts downtown, and local papers are busily interviewing those "pioneers" who remember what the town was like when it was only one apartment development and a lot of mud.

Today the 14,000 acres of farmland - nearly 10 per cent of Howard County - that developer James W. Rouse brought up in the mid '60s has nearly 44,000 residents, 20,000 jobs, 750 businesses, three lakes, two golf courses, four colleges, two high schools, four middle schools, 11 elementary schools, three indoor pools, 13 neighborhood pools, 44 tennis courts, one hospital, 11 major religious congregations and 1,900 acres of permanent open space.

"And one McDonalds," Ruse concluded with a grin after reciting Columbia's vital statistics at a recent meeting here.

Columbia now has 35 per cent of the county's population and accounts for 42 per cent of its taxable base.

Columbians boast of the "openess" here, of life in a people-scaled multiracial town where even the churches share the same jointly owned facilities. Old timers also tend to charge that newcomers often move here less for the "Columbia dream" than for the fact that housing is available, and there are lots of amenities.

Still, whether vintage resident or Johnny-come-lately, Columbians are having themselves a party, a 2 1/2-week bash organized partly by the developer and partly by an estimated 300 hard core volunteers on 30 major committees who have been at work since January.

The celebrations started last wekend in most of Columbia's villages. There were three-legged races, pet shows where everybody won a prize, pie-eating contests, baking competitions, ethnic foods, free bluegrass and jazz concerts, watermelon, hot dogs, cheap beer and free balloons.

It was, as one resident put it," a Norman Rockwell kind of day. You know, the kind of thing most adults feel they should have experienced as a child but probably never did."

The village of Long Reach had a belly dancer, pony rides and a bike race but had to cancel its tug-o-war contest. The people in the village of Harper's Choice, it seems, never got around to sending over the rope when they were finished with it. "Would you believe in all of Howard County there's only one tug-o-war rope?" asked a volunteer with a philosophical shrug.

The village of Owen Brown had its fourth annual picnic, with game for all ages, including a baby race for the pre-toddler set.

Timmy Breeze, aged one year and one week, demonstrated a truly impressive crawl to win, although he very nearly blew the race when, distracted by cheers of "go, Timmy," he sat up to beam at his admirers halfway through. Joel Waxman, on the other hand, put his head down at the start of the race, stuck his thumb in his mouth and took a nap. His mother, Judy, explained that the five-month-old "found the competitive very stiff."

In Wilde Lake village, the second two-kid heat of the big wheel races resulted in on-the-spot rule that professional racers might envy: in the event of a crash, the unscathed driver wins while the crashee gets picked up, cuddled and is allowed to try again.

The weekend also included an inter-faith service next to Lake Kittanaqundi, an evening lakeside show and dance for teens and the seminar sponsored by the nearby, non-profit Columbia has had on native flora and fauna.

While last weekend's activities were pretty much homefolk affairs, the festivities this weekend and next are aimed at attracting county-wide and region-wide visitors as well." And in a community where 'traditional' means an we-did-it-last-year-too, and 'annual' means maybe-we'll-do-it-again, two of the upcoming events include the first annual Columbia Olympic and the first annual city fair.

Along with neighborhood parties and a 1,000-person birthday ball in the mall that sold out in three days, this weekend will feature a 16-mile marathon race on Sunday and the Olympics, which open tomorrow.

A carnival was to open in downtown Columbia yesterday and is set to run through July 4. The city fair, with more than 100 arts, crafts and international food booths as well as free music and entertainment, will run from July 1 to 4. Independence Day celebration will include a parade at 10 a.m., and fireworks at Lake Kittamqundi starting at 10 p.m.