Prince William Board of County Supervisors Chairman Corey A. Stewart (R-At Large) has proposed substantial funding cuts to area social service programs and nonprofit organizations to ensure that residential real-estate tax bills remain flat next year.

In a letter to supervisors, Stewart outlined $9.6 million in potential cuts that would significantly reduce funding for the county health department, the Juvenile Court Services Unit and substance abuse treatment for jail inmates, among other services. He also proposes eliminating some funding for nonprofit groups, including Legal Services of Northern Virginia.

The full effect of the potential cuts is not yet known. Stewart has asked county officials to study the proposal and report back.

Stewart said in the letter that “uncertainty created . . . at the federal and state levels,” including possible tax hikes and cuts in defense spending, mean that the county must rein in its budget so homeowners do not receive a tax increase.

The cuts are a starting point, he said, and if county staff members determine that the proposed cuts are dangerous or ill-conceived, he ould reconsider.

Stewart said his “initial instinct is skepticism about social government,” and that is what drove the proposal. “[People] didn’t vote for me because I was a big advocate of social welfare programming,” he said.

Other supervisors are releasing proposals. Supervisor Martin E. Nohe (R-Coles) applauded Stewart for producing a plan, which he said would serve as a good starting point for discussion. He said he wants to know more about the effect of the proposed cuts before deciding whether to support them.

Nohe said he is awaiting decisions on possible severe federal government spending cuts, which would occur if Congress does not act before Jan. 1, before taking a position on the budget. “Until we know what’s going to happen there, anything we want to do about next year’s budget is basically a hypothetical budget.”

The board is expected to advertise a proposed real estate tax rate Feb. 21 and adopt the fiscal 2014 budget April 24.

Robert Zelnick, a lawyer on the board of Legal Services of Northern Virginia, said the potential cut in county funding is “very distressing.” The organization provides free legal assistance to low-income, elderly and disabled residents in Northern Virginia.

“We are facing decreased funding from all sources, and we are facing increased demand,” Zelnick said, adding that more people need the group’s services — and more people qualify for them — because of the troubled economy. The funding issues have resulted in staff positions going unfilled, he said. “This would be a devastating blow to the organization.”