The Ventura County Board of Supervisors voted Tuesday to spend as much as $16.7 million on a new communications network that should eliminate most of the radio "dead spots" emergency workers encounter.

With the current system, firefighters, paramedics and sheriff's deputies often can't reach central dispatchers with their hand-held radios. They must use the mobile radios in their cars and trucks instead, and that can sometimes slow down calls for assistance, said Jim Norris, the Ventura County Fire Department's information technology manager.

"This is where the rubber meets the road in the delivery of services," he told the board. "If a deputy is at the scene of a gang fight, he might not be able to go back to his car, to his radio."

The new system will have "acceptable audio quality" in about 95 percent of the county's populated area, he said.

The system has been in the works for months now; Tuesday's series of votes by the Board of Supervisors authorized additional spending and contracts with vendors to implement it.

The communications network will include five new microwave towers, upgrades to 11 existing microwave towers, and a new Motorola handheld radio system. It should be in place in three to five years, Norris said after the board meeting.

The portions approved by the board on Tuesday include a $2.7 million increase, or 45 percent, in the anticipated cost of the microwave tower network. The increase was noted by Supervisor Linda Parks, who asked Fire Department and information technology managers to return to the board with further updates on whether the project will reach its maximum cost allowances.

"This is definitely needed, and I'm glad we're moving forward on it," Parks said. "It will help increase the safety of our officers out there who don't have radio contact in these pockets of the county. I just want to make sure we keep it within reasonable cost."

The cost will be split among the Sheriff's Department, Fire Department and Information Services budgets. County Chief Information Officer Richard Jackson said some of the money could be recovered by selling the network's unused bandwidth — for example, to hospitals that need to transmit MRIs and other large files.

The system will have far more bandwidth than the county will require for its radio voice data, Jackson said.

"As we move forward, we could put real-time video on there," so dispatch centers would be able to see when sheriff's deputies and firefighters reach a site, he said.