After nearly 20 years, the distinctive white puffy dome covering the field house at Woodbury's Bielenberg Sports Center will be — for both the first and last times — deflated as the city prepares to replace the bubble with a fixed roof that's part of a major expansion and renovation.

When the Woodbury Business Expo, a promotional event sponsored by the Woodbury Chamber of Commerce wraps up activities on April 6, it will be the last event under the roof that has held up through summer storms and winter blizzards.

"Our dome has been fabulous," said Dave Black, the sport center's manager.

Black, who was there when the dome was installed in 1995, said it has never been completely deflated in all that time. On a couple of occasions, after a severe straight-line windstorm and the same 2010 snowstorm that deflated both the Metrodome and the dome of the Vadnais Heights Sports Center, pressure was eased on the Bielenberg bubble to prevent damage. "We've had the good fortune of being located in a low-lying area," Black said. "I think that's helped us a lot."

Construction on the Bielenberg Sports Center project is set to begin in April. A few days after the Business Expo, demolition crews will carefully let the air out of the dome, and it will probably take several days to unbolt all the fabric and remove it from the site, Black said. Its fate is unclear, but it might be sold to another community or private party for another use. The life span was projected at 15 to 20 years.

Unlike a coming replacement, the dome was never meant to be permanent, Black added. When Augsburg College in Minneapolis installed its domed field, making summer sports possible in winter in a building that was not a modified warehouse or hockey rink, local athletic groups took notice. Woodbury decided to make a commitment to the domed field house next to its two hockey arenas, and it was an immediate hit, he said.

Now, a new commitment is being made to an enduring building that will serve decades into the future, and not just athletic groups, but a host of other activities as well. "We're trying to make this a community, year-round building," Black said, that could be a regional draw.

On Wednesday, the Woodbury City Council made the final decisions in what has been a years-long planning effort. Bids for 20 of the 24 contracts that the construction project will entail — totaling about $16.7 million — were awarded. The four other contracts, about $1.2 million worth, were held pending further review. The $17. 9 million is about $400,000 less than the $18.3 million construction budget.

Sale of voter-approved bonds, along with the use of reserve funds, will allow the project to be built without raising property taxes.

Along with replacing the dome with a permanent, metal roofed building, the worn field-house turf will be replaced and the field house will grow from 50,000 to about 90,000 square feet, large enough for a full soccer/lacrosse field. A much-expanded lobby, meeting room and other amenities will add another 30,000 square feet.

Other features: an outdoor refrigerated recreational skating rink with a concrete pad that could be used for other sports in the summer; a full food-service area; a building for storing vehicles and equipment to maintain the outdoor fields.

There also will be a geothermal heating/cooling system; solar panels for heating water and upgrades of the center's two skating rinks.

Jim Anderson • 651-925-5039

Twitter: @StribJAnderson