Journey, the classic '70s rock band, wrote a hit single about what happens "when the lights go down in the city."

The city of Gainesville, on the other hand, prefers to keep the lights on.

So when the city's Public Works Department discovered it underestimated the expenses to pay the 2012 power bill for street and traffic lights — to the tune of $95,000 — it had to request additional funds from city coffers.

Gainesville City Council authorized the additional spending earlier this month.

"There was a combination of things that led to the anticipated budget shortfall next year," said David Dockery, the director of the Gainesville Public Works Department.

For one, he said, the department did not account for increased fees and rates from Georgia Power when it drafted its budget.

The other reason was the city adopted several streets this year before the city normally would. When Gainesville adopts a city street, it agrees pay streetlight power bills.

This year, Gainesville took on new streetlights from subdivisions that had begun construction before the economy tanked, only to have building halted, Dockery said.

Typically, subdivision builders are responsible for meeting zoning codes with the implementation of streetlights and drainage arrangements.

However, some communities, including the Mundy Mill, the Gardens and Windsor Forest subdivisions, were essentially abandoned from further construction before they met zoning codes.

Because of public safety concerns — the few residents who lived in the incomplete neighborhoods didn't want to live on an unlit street — the city agreed to "accept" the street and take on the street light power bill, Dockery said.

The additional funds, $88,000 for streetlights and $7,000 for traffic lights, came out of the city's $520,000 contingency fund, said Melody Marlowe, Gainesville's administrative services director.

The Public Works Department had originally budgeted $420,000 for streetlights and $42,500 for traffic lights.

The shortfall was discovered during a regular inspection of the department's budget.

"We have quarterly meetings to review these types things," Marlowe said. At this point, she said, no other department underestimated its power bill.

The department with the most energy use in Gainesville is the Public Utilities Department, where the bulk of the use goes toward water treatment facilities.