Sonoma County supervisors Monday gave preliminary backing to spending plans for most county departments during their first day of hearings on a 2012-2013 budget.

The board is considering a $383.9 million general fund budget for the fiscal year beginning July 1. The figure is down just under 1 percent from the current year.

It projects flat county appropriations, resulting in a an equivalent of a 5 percent to 8 percent general fund cut for most departments.

Supervisors on Monday indicated they were comfortable adding more than $20 million in spending, mostly in the form of state dollars for human service and criminal justice programs shifted to the county.

The overall budget, including state and federal dollars, is set to be about $1.3 billion, up more than 4.6 percent from the current year. The funding bump includes $26 million in federal grants for expansion of the county airport.

Supervisors reviewed in detail the budgets for 18 departments and endorsed plans for about 10 others through a combined consent agenda vote.

A final vote is expected Tuesday after discussion of library and advertising budgets. The hearings resume at 9:30 a.m. The board's regular weekly meeting convenes at 1:30 p.m.