SEASIDE — An estimated $28 million expansion of the Seaside Civic & Convention Center is being considered by the Seaside City Council.

The proposal was unveiled Monday night by convention center General Manager Russ Vandenberg.

Before any action is taken on it, however, city officials need time to determine where the money would come to pay for it, said Mayor Don Larson.

“We’re not building it tomorrow, but we’re not throwing it away,” he told the City Council and members of an ad hoc committee organized three years ago to begin studying the need for expansion.

After the meeting, Larson said the council had to determine if it wanted to commit so much money to add a ballroom, new meeting rooms and double the amount of event space at the 62,000-square-foot convention center.

The expansion would add 20,500 square feet of new meeting space and 7,600 square feet for a new riverfront reception area.

In addition to the new space, the center’s reinforced roof could also act as a tsunami evacuation refuge capable of temporarily holding 2,000 people.

“The money is a huge factor here. We have not yet established that the expansion would be worthwhile. We’re not saying it’s too expensive; we have to find out where the money would come from,” Larson said.

“We’ve got too much into this without doing some thinking and planning,” he added.

 The proposed design – one of three that was considered – would extend the center to the east toward the Necanicum River and 20 feet south on an existing parking lot and land not owned by the city. It would partially encroach on the western edge of Quatat Park to accommodate a new 12,500-square-foot ballroom.

The expansion would also solve an existing problem: Meetings cannot be held in the Pacific Room when it is also used as a dining room. An expanded center would provide additional dining space in the ballroom.

Capacity in the larger center would double, from a maximum of 400 people now to 800. The expanded center could accommodate 79 percent of the conventions event planners book within a 300-mile radius, Vandenberg said. The current space meets the needs of only 42 percent of those events.

The center’s lower rates and the coastal location draw event planners’ interest, “but our limitation is space,” Vandenberg said.

In 2010, the center was booked 239 days, only three days fewer than in 2009.  Its estimated economic impact on Seaside last year was $25 million. Expansion could increase the impact by 34 to 56 percent, according to documents Vandenberg distributed.

However, he added, it would take five years before the city saw an increased economic impact if the center were expanded immediately.

With expansion, the center could be double-booked with two concurrent conventions, although, Vandenberg admitted, it might be a struggle for the staff.

 “We’re doing two- and three-hour turnarounds now so we don’t turn business away,” he said. “As soon as one group is out, another comes in. We’re stretching now.”

One of the two alternative designs would have expanded the center east into the Necanicum River, which could affect a designated environmental conservation area. The second alternative called for expansion to the west, into an existing parking lot, but that would have removed half of the available parking space and would have required construction of an additional kitchen.

Since it was built in 1971, the convention center has been expanded twice: in 1978 and in 1991. To finance the original construction, the city received a grant from the Oregon Lottery and imposed a business license tax and a 5-percent lodging tax. The city’s current lodging tax is 8 percent, slightly higher than Cannon Beach’s 7 percent tax, but lower than Portland’s 11.5-percent tax.

City Councilor Jay Barber suggested that, since the center’s roof might be used as a tsunami refuge, the city might be able to apply for outside grants from federal and state agencies.

Concern also was expressed about the number and quality of area hotel and motel rooms. Vandenberg admitted that in some establishments “the rooms are tired.”

The city began looking at expansion three years ago by forming an ad hoc committee. Consultants prepared reports looking at the demand and need for upgraded facilities in a 300-mile radius, which would attract people driving to Seaside. So far, the city has spent $60,000 for a needs assessment and the latest master design plan, Vandenberg said.