York City officials are cutting it close with plans to transform the former city hall into a new police headquarters.

Costs for the $5 million project already have exceeded expectations, and there's now just $90,000 available to cover the unexpected issues that are bound to pop up.

And that's after officials borrow $100,000 from funds left over from two other recently completed projects.

The money for the work at 50 W. King St. -- which will result in a modern, accredited police station -- came from a state grant, and city officials repeatedly have pledged not to spend local taxpayer dollars on the project.

That's looking increasingly unlikely, however.

In fact, one could argue officials al ready are using local tax dollars if they tap the $190,000 remaining in an account used for City Hall's move to 101 S. George St. and energy-efficiency upgrades.

Contracts approved in October were worth nearly $4.7 million and covered most of the construction work at the police station. Earlier engineering costs amounted to about $250,000, leaving a little less than $100,000 in the budget for the installation of an information-technology system, the last contract to be bid.

Public Works director Jim Gross this week asked the city council to approve a $200,000 IT contract -- the best he could do after three bid openings and a round of negotiations.

Gross wants to use the $100,000 remaining in the police-station budget and part of the $190,000 remaining in the other account to pay for the IT system. Assuming the council approves the contract, that would leave the city with a cushion of just $90,000 to cover any unexpected costs.

That's a pretty thin cushion for a project of this scale, especially when we all know we probably should expect unexpected expenses. (It would be more appropriate to call them "unknown" costs.)

Remember the York County Judicial Center? At a cost of $62 million, the building was $7 million over budget when it opened in 2004.

Around the corner on East Market Street, the renovation of the parking garage was completed in 2010 for $4 million, or $500,000 more than originally estimated.

Construction at the police station was scheduled to begin this month but is on hold until the IT contract is finalized. Once under way, the project is expected to take about 18 months to complete.

A lot of things can happen in a year and a half. A lot of expensive things.

Gross said if the unexpected costs amount to more than $90,000, a private donor might step in to help.

Hopefully, that means a private donor already is lined up and waiting in the wings with fairly deep pockets.

City officials shouldn't even consider flip-flopping on its pledge not to use local tax dollars -- not when property owners here are struggling under the highest, by far, tax rate in the county.

If it ever looks like the project will exceed the amount of funds on hand, that will be the time for city officials to scale back their expectations and accept what they can get for $5.1 million.