What would happen to the emergency needs of the public if an epidemic or catastrophe sickens police officers and shuts down local police stations?

Who responds to the roadside emergency 911 call if the local department's officers are all out with the H1N1 flu?

With flu, swine and seasonal, striking in historic proportions, decimating school populations and other establishments, the notion isn't as far-fetched as it might sound. Realizing the hazard, regional police chiefs have begun working together to come up with a plan to cross town lines and help each other.

"This is a discussion of 'what if,'" said Georgetown police Chief James Mulligan. "For example, what would happen if all my people were sick and my building shut down because it was contaminated? It could be from a pandemic of the H1N1 flu or any catastrophe. A fire or an oil spill could shut us down, too. The idea is to formulate a regional plan to deal with the possibilities."

Mulligan said police chiefs and emergency management directors from Merrimac, Rowley, West Newbury, Newbury, Newburyport, Georgetown, Groveland and Salisbury met this week to discuss a number of scenarios that might work for the region.

Some of the departments are fairly small — for example, Salisbury has less than 14 officers, Georgetown has 10 full-time officers, and Newbury has 14 full-time officers. West Newbury has about a half dozen.

West Newbury police Chief Lisa Holmes and Salisbury police Chief David L'Esperance are heading up the project and will report back to the group with a suggested plan.

The remedy is needed, Newbury police Chief Michael Riley said.

"Our people deal with the public, and we deal with people whether they're sick or not sick," Riley said. "We take all the prescribed precautions, but I think it's only a matter of time before something happens somewhere. I think it's prudent that we consider this issue."

Riley said the plan would possibly include formal agreements between departments, ensuring no communities suffer should their police departments become seriously depleted for any reason.

Each department at the meeting discussed its own individual emergency plans, Riley said. The new plan might take some of those ideas into a regional approach.

Another issue for consideration is how to cope if more than one police department becomes critically affected by a pandemic of flu at the same time.

If 40 percent of Riley's work force were affected by flu, he'd reach out to other departments asking for back up, and maybe see if other departments could send over officers to help out. The regional plan could formalize some sort of cooperation.

Georgetown and Rowley police departments have an agreement in case either has to close down, Mulligan said.

"We can switch all emergency 911 calls coming into our department to Rowley if our station is shut down," he said. "Our units would then be dispatched out of Rowley's communication center, and we could set up operations out of the classroom in the Rowley police station. And that would work in the reverse as well, if something happened to Rowley."

The idea of working together on a regional emergency plan came from L'Esperance, Mulligan said.

Fire departments have strong regional mutual aid agreements and send equipment and firefighters over to fight fires in other towns at the sound of alarms, L'Esperance said. They send crews to cover each other's stations when they're emptied because all firefighters are out at a fire.

Although police departments have mutual aid agreements, he said, they aren't as encompassing as fire department's and he felt something's needed to protect the public.

"What this idea is about is cooperation," Riley said, "and helping each other out."