The St. Helena City Council has agreed to a temporary hiring freeze in anticipation of a significant dip in city revenue due to the struggling economy.

The freeze affects four unfilled positions or promotions, including one sergeant upgrade at the city police department. It doesn’t affect an opening in the public works department.

Councilmembers warned this is just the first step in what could become a series of painful cuts to the city’s general fund.

City officials are proposing that library hours be cut and vacant city staff positions remain unfilled in an attempt to trim the budget to compensate for the economic downturn.

In December, the council asked Finance Director Karen Scalabrini to come up with ways to cut the $9 million general fund by $250,000 or $500,000, depending on the severity of the crisis. The general fund represents about 58 percent of the city’s budget.

On Tuesday, Scalabrini said that under the $250,000 scenario, the library would close on Sundays and it would be open only for four hours on Mondays.

At City Hall, four unfilled positions would continue unfilled; promotions would not occur; and three part-time positions would be eliminated. Training and supplies would be reduced in most departments, and there would be less water used at city parks.

The $500,000 scenario would call for two more positions to be cut and for reduction of hours at another position. There would be further equipment and supply cuts, and the general fund’s contribution to the flood control project would be reduced to virtually nothing.

The council will schedule a work session to take a more in-depth look at the proposed cuts. But the $250,000 scenario is being considered the minimum of what will be necessary.

The severity of the crisis is hard to calculate because some key revenue figures lag about a quarter behind, Scalabrini said. But based on anecdotal reports, officials are expecting significant decreases to three of the city’s biggest revenue sources: property taxes, sales taxes and transient occupancy taxes generated by hotels.

Sales tax revenue looks to be on target, but that’s because the most recent numbers only cover revenues up to Sept. 30, officials said. The next round of numbers, available in February or March, should reflect the steeper sales declines that began in October.

Scalabrini said that through her regular meetings with local business leaders, there is a sense that “in October the sales just dropped out.”

Scalabrini has said the hotel tax could fall by as much as 25 percent.

Councilmember Eric Sklar, who sometimes acts as a consultant to the hotel industry, said that according to his sources, hotel occupancy remained relatively strong through Christmas — because many people had booked their reservations prior to the downturn, and didn’t want to lose their deposits.

But after Jan. 1, occupancy rates plummeted by as much as 20 or 30 percent, said Sklar.

“We’re getting more day travelers from the close Bay Area who are spending money at wineries, but they’re not spending the night,” he said. “In the hotel business, the numbers we’ll see for January and February are going to be shocking.”

The council said it will continue to review the status of the city’s three main revenue sources monthly.