EDITORIAL : A PLAN WORTH TRYING TWIN TOWERS JAIL IS USELESS AS LONG AS IT STAYS VACANT.

Los Angeles County officials finally have figured out a way to turn their embarrassing symbol of dysfunctional government into something useful.

They have cobbled together a plan to move prisoners into the year-old, still-vacant Twin Towers jail. That facility has been a huge source of chagrin ever since red-faced officials said they had no money to operate the 4,100-bed, $300 million jail after it was completed in August 1995.

Meanwhile, prisoners were (and still are) routinely released ahead of schedule because of overcrowding in county jails. The lucky lawbreakers are set free after serving only a fraction of their sentence to make room for new arrivals.

But last week, the county Board of Supervisors approved a series of steps aimed at opening Twin Towers and improving the county jail system. The plan involves shifting prisoners among county facilities and closing some locations, at least temporarily.

Some prisoners will be shifted from the violence-plagued Pitchess Honor Rancho in Saugus to Twin Towers' locked-down, high-security cells. That will improve safety for them and others in the jail system. In addition, all prisoners at the Sybil Brand Institute for Women - the county's only jail for women - will be transferred to the Twin Towers. (Sybil Brand Institute is overdue for $35 million in repairs and renovation).

The county also expects to contract with state and federal governments to provide detention services, opening the now-unused Mira Loma jail in Lancaster to house undocumented immigrant detainees for the U.S. Immigration and Naturalization Service.

To make the plan work, the county still must come up with $14 million to run Twin Towers this year and $16 million next year. That won't be easy because the budget already is stretched and financial uncertainties abound. But as Sheriff Sherman Block and others have pointed out, the cost is less than the $18 million that supervisors recently vowed to spend to reopen only one of the towers for just six months.

This new plan certainly isn't foolproof. If any element fails, the final cost could rise dramatically. For example, the county expects to raise millions of dollars in new revenue - perhaps as much as $37 million - by providing detention services for up to 1,900 state and federal prisoners and INS detainees. Can that really be done? And how soon?

But given the critical importance of the county jail system and the amount that already is being spent on it, the plan does seem to offer real improvements. And for those reasons, the idea deserves a chance. We just hope county leaders can make it work.