T. Rees Shapiro:

Although the Fairfax County School Board faces projected budget deficits and each year asks the Board of Supervisors for more taxpayer money to fund its regular operations, it also has found a creative way to pay for projects and add items to classrooms: a fund filled with millions in leftover cash.
Fairfax’s school system has ended each budget year with an average of $30 million in unspent funds from the system’s budget during the past decade, a budget that topped out at $2.5 billion this past year. The leftover cash, ranging from $4 million to $55 million, is usually generated from savings — such as heating bills that are lower than projected during a mild winter — or from unforeseen revenue increases, including income that was higher than expected from county sales taxes.
The leftover money accounts for about 1 to 2 percent of the school system’s annual budget, but that portion often amounts to a considerable sum worth tens of millions of dollars that can be used at the School Board’s discretion. Over the past 10 years, the leftover funds have added up to more than $305 million.
While the board often elects to use the extra funds to balance the following year’s budget, a sizable figure has been used for what amounts to a school system wish list. The outlays in recent years have included $400,000 for BlackBerry smartphones for administrative staff, $500,000 for adding automatic external defibrillators at schools, $693,000 to place assistant principals in all elementary schools and $375,000 to expand a culinary arts program.
All while the School Board has stared down deficits. In 2015, for example, the school system must address a projected $195 million deficit driven by rising enrollment figures and compensation needs. The school system had about $55 million left over this year and will use about $10 million of that to purchase new school buses and add three positions to the system’s legal staff.
Arthur Purves, president of the Fairfax County Taxpayers Alliance, said he thinks the school system’s millions of dollars in leftover cash are a symptom of a larger problem. He said the extra money, when combined with tens of millions of dollars in reserves and other “extraneous” items, suggests significant “padding” in the annual budget.
“It is suspect,” Purves said, adding that, as a “persnickety tax watchdog,” he thinks the school system budget is bloated with such expenses.

Related: Fairfax plans to spend $2,500,000,000 during the 2013-2014 school year for 184,625 students or $13,541/student, about 14.4% less than Madison’s per student spending.