About half of the San Diego Police Department's current force of 1,833 is eligible for retirement over the next four years. That’s a troubling statistic for a department that already has 300 fewer officers than a decade ago.

At the same time, the city is struggling to keep its best young officers from leaving, some of whom are being lured by other law-enforcement agencies that are promising more take-home pay and offering $5,000 signing bonuses. Three out of every 10 officers hired by the city since July 1, 2005, have left, the equivalent of about eight percent a year, the San Diego Union-Tribune reports.

An argument could be made that the city’s shrinking police force fits the times. Crime levels are near historic lows so the department has clearly been able to adapt with fewer officers. A recent study commissioned by the U.S. Justice Department showed the recession forced many communities to downsize their law enforcement agencies and rethink decades of policing strategies.

Still, the concern at City Hall is how long the Police Department can continue performing at a high level before it reaches a breaking point.