The Douglas County Commission on Wednesday will host a public hearing on the proposed 2015 county budget, which includes a nearly 4-mill property tax increase, before voting on the budget.

The proposed 3.914-mill increase would be the highest since 1985, when it expanded by 4.4 mills. It would up the property taxes of an average $185,000 home in Lawrence by about $83. A mill is $1 in taxes for every $1,000 in assessed valuation.

Commissioners preliminarily approved the budget in mid-July.

Commissioners and the county administrator, Craig Weinaug, have attributed much of the increase to actions by the state government that affected revenue streams or produced new expenses. Among them, the Legislature decided to phase-out the mortgage registration fee, reduce tax rates on boats, require the county to increase its workers’ compensation reserve fund and require the county to hire independent appraisers in tax disputes with industrial property owners.

Also included in the budget is $165,000 for a youth mental program by the Bert Nash Mental Health Center, $77,000 for a media information and technology specialist in the district attorney’s office, and four additional corrections officer positions in the Douglas County Jail to serve an increasing number of inmates with mental illnesses.

The commission will meet at 6:35 p.m. at the Douglas County Courthouse, 1100 Massachusetts St.