The letter sent to Fairfax households this month contained a stark warning: Due to budget cutbacks, the county's libraries will have to do without critical resources.

"Will you help us?" it pleaded.

Swamped with patrons and strained by budget trims, the county's 21-branch library system faces an additional $1.4 million in reductions next year on top of hiring freezes that have left 60 positions unfilled and a book budget that has been slashed by a third each of the past four years. Now more than ever, fundraisers with the nonprofit Fairfax County Public Library Foundation are aggressively seeking contributions from individuals.

"If the cuts continue to be severe, then it's really going to change the balance of what people expect from the library, because it will change what the libraries are today," said foundation Chairman Patrick J. Dexter. "Without the private funds we're raising, the satisfaction of the library patron would be less and less."

The foundation was started eight years ago by the library's board of trustees. Faced with a 50 percent cut in county funds, the board decided that a stream of private, long-term revenue was the only way to ensure the system's health. The money was not then, and is not now, intended to replace county and state dollars, but rather to supplement them, officials said.

It seems to be working.

Last month, the foundation reached the $1 million mark in its $3 million New Century Library Fund campaign. The money is being held in reserve to have a larger impact on services at some future point. Officials hope that the endowment will reach $20 million, generating $1 million annually to buy materials, develop programs, update technology and provide scholarships.

"We see this as an investment in the future," said Roberta A. Longworth, the foundation's executive director. "The fund is long-term security."

Fairfax's library system, the largest in Virginia and the Washington area, circulated 12.1 million books, videos and other materials last year, a 5 percent growth rate that set a new high. There were 5.5 million library visits, an increase of 8 percent from 1998.

Foreign language materials are now the fastest-growing collection and one of the most used. The system's 3,630 Vietnamese books, for example, were checked out a total of 34,900 times last year.

Library officials, trying to offset an anticipated 5 percent cut in county funding for fiscal 2004, have proposed trimming $404,842 from the budgets for computer hardware maintenance, training, furniture and other items.

Hardest hit, however, would be materials. Officials are prepared to make a $1 million cut there, which translates into about 42,389 books and other items they would not buy in the coming fiscal year. "Patrons will notice," particularly those who rush to check out the latest bestsellers, said Edwin S. Clay III, director of the library system. "The wait to get them will be longer."

Since the foundation was formed, campaigns such as this month's annual fund drive have brought in more than $1.4 million for day-to-day use in addition to money to keep the foundation and its efforts afloat.

Among the most notable gifts received was a recent $500,000 endowment pledge from the Friends of the George Mason Regional Library to ensure the continuation of a summer reading program. ExxonMobil Corp.'s donation of $20,000 is being used to expand the library system's children's foreign language collection through the purchase of 833 Korean books. And much of the system's audiobook collection is being paid for with a $1 million donation from Orrin W. Macleod, a world traveler and former baggage handler for Eastern Airlines whose vision was damaged by illness. His gift, arranged before his death in 1994, brings in an average of $50,000 each year for recorded books.

"I think the board's position is that for the longer-term health and prudent management, you have to develop additional revenue streams," Clay said. "Not in lieu of public money, but to enhance it."