The city budget crisis has come to this:

Senior city officials now worry that the cuts they are considering could lead to an explosion in the city rat population.

Yes, the rat population.

Ending weekly trash collection - which prompted the hand-wringing over rodents - was one of a host of drastic potential cuts floated for the first time at a city budget meeting yesterday.

No decisions have been made, and other options - such as tax increases and the restructuring of some independent agencies and offices - are being considered, administration officials said.

But the handful of potential cutbacks mentioned suggests that next year's budget will be grim indeed.

Services for the homeless and already-scarce affordable-housing money could get hit hard, warned Donald Schwarz, deputy mayor for health and opportunity.

The city might also be forced to reduce restaurant inspections, close health clinics, and charge new fees for health services at the remaining clinics, Schwarz said. He did offer one bit of good news: The city will try to avoid closing the 11 library branches that the administration wanted to shut down at the beginning of this year, before a legal challenge put a halt to the plan.

Deputy Mayor Andrew Altman, who heads the city planning and economic-development departments, said cuts now being considered would have a direct and noticeable impact on city services.

"We're already past the point where efficiency gains are going to get us very far," Altman said.

The fund that pays for emergency demolitions of dangerous buildings could get slashed, Altman said, and the already-slow processing of permits at the Department of Licenses and Inspections is likely to take longer still if staff reductions are made. Deep cuts would also limit the city's ability to go after property owners who violate building codes, Altman said.

In November, as the national economic crisis forced the city to reduce its revenue projections, Mayor Nutter and his lieutenants cut $1 billion from the city's five-year spending plan, largely through a combination of cuts and freezes on planned tax reductions.

Those reductions - which were met with fierce opposition at town meetings - were painful enough. Now, after three months of further economic collapse, city departments are being told to cut deeper still to close a new $1 billion budget gap covering the years 2009-14.

With numbers that big, the cuts under consideration range from "the least to the most catastrophic," said Rina Cutler, deputy mayor for transportation and utilities.

It was Cutler who first mentioned the rats.

She said cutting back on the collection schedule was one of three sanitation options being considered.

The others: Privatization, which could lead to extensive layoffs (the sanitation division employs nearly 1,300 workers), and levying a new trash-collection fee.

No fee was mentioned for recycling collections.

The potential cuts were discussed at a meeting that was open to the public. The city has committed to providing a detailed breakdown of the proposed cuts at future public meetings and seeks public input on the proposals before the mayor delivers his budget to City Council on March 19.

Contact staff writer Patrick Kerkstra at 215-854-2827 or pkerkstra@phillynews.com.