The Loudoun County Board of Supervisors on Tuesday approved a $2.5 billion budget for the county government and school system for fiscal 2018.

The spending plan provides funding to open several new facilities, give pay increases of 3 percent or more to county and school employees, and add hundreds of government and school staff positions. By lowering the real property tax rate 2 cents, to $1.125, the supervisors also reduced tax bills for most Loudoun homeowners.

Still, several supervisors expressed dissatisfaction because the plan falls $5.5 million short of the school board’s funding request.

At a final budget work session March 20, and again at the board meeting Tuesday, the board’s three Democrats backed several attempts to close the gap by shifting more money to the school system. They were thwarted each time by the Republican majority.

Supervisor Tony R. Buffington Jr. (R-Blue Ridge) made the motion to approve the spending plan and tax rate at the March 20 work session. He said the school system would be able to close most of the gap by scaling back proposed pay increases for its employees, while still providing them with raises of at least 4 percent.

“I have two kids in the system myself, and I have complete confidence that this motion will address all of their needs and the vast majority of their wants, while improving the education system as a whole,” Buffington said.

Board Chair Phyllis J. Randall (D-At Large) expressed frustration after her attempt to shift $1.5 million to buy new textbooks failed.

“We talk all the time about listening to the voice of the constituents . . . until we get to the budget, and when we get to the budget, the voice of the constituents is right out the window,” she said.

Randall said that very few speakers at the public hearings had advocated tax cuts, and that the “vast majority” of letters and emails to the supervisors urged full funding of the school system’s budget request.

“Why is it every time we talk about the voice of the constituents, it matters on every issue except for the budget?” she said. “And the voice of the people has not said, ‘Get down to $1.125.’ ”

Randall continued to press for more school funding at Tuesday’s meeting.

“The effort to get down to a certain tax rate is not the way to go about a budget process,” she said.

“We had supervisors up here starting at the point of, ‘I will totally fund the school budget request no matter what it is,’ ” Supervisor Ron A. Meyer (R-Broad Run) said. “My question is, then why do we have a Board of Supervisors?”

“We’re being asked to literally be a rubber stamp for the school budget and not provide any oversight whatsoever, and not disagree with any single thing in that proposal,” Supervisor Matthew F. Letourneau (R-Dulles) said.

The board voted 8 to 1 to approve the overall spending plan and tax rate, with Supervisor Koran T. Saines (D-Sterling) opposed. The six Republican supervisors rejected subsequent motions by Randall and Supervisor Kristen C. Umstattd (D-Leesburg) to shift funds to buy school buses and textbooks.

The budget for the general county government provides funding to open several facilities, including the Kirkpatrick Farms Fire Rescue Station, Brambleton Library, the Ashburn Sheriff’s Station, and senior and recreation centers in the expanded Dulles South Multipurpose Center. It adds 212 staff positions and includes a 3 percent merit pay increase for eligible county employees.

Several supervisors attributed the relatively painless budget deliberation process to the booming local economy.

“We had a lot of revenue coming into the county through commercial investment and economic development,” Letourneau said in an interview. “It makes our job a lot easier.”

Data centers have become a major source of revenue, generating more than $150 million annually, county officials said.

“Data centers are certainly contributing in a big way to our tax base,” Letourneau said. “But we’re also seeing job growth. We were No. 1 in Virginia, No. 3 in the country last year, and that’s largely not data-center-driven.”

Vice Chair Ralph M. Buona (R-Ashburn) said it was the easiest budget process he has experienced in his six years on the board.

“Budgets are a little easier in good times than they are in hard times, and when revenues are up, budgets are easier,” Buona said.