Fairfax County lawmakers yesterday angrily clashed over roads and growth -- two big-ticket issues that are likely to be echoed and amplified in next year's elections to the county board.

Supervisor Audrey Moore (D-Annandale), the county board's most dogged opponent of development, antagonized nearly all her colleagues with the suggestion that the county staunch its rapid growth.

Moore's immediate target -- the expansion of the county's sewer capacity -- seemed prosaic enough. But for more than a decade, more sewers have meant more growth in Fairfax, and for more than a decade Moore has opposed both.

Saying that nearly $500 million of the county's planned capital expenses through 1991 is for expanding sewer capacity, Moore suggested that the county is priming for a population boom without having built enough roads for the people already living there.

"The board is so in love with development that they're making sure there won't be any hindrance for it," she said, "but they haven't got the roads for the people who are already here."

Moore's comments brought lacerating replies from county lawmakers.

"An inane argument," scoffed County Board Chairman John F. Herrity. "Irresponsible remarks," complained Supervisor Elaine N. McConnell (R-Springfield). "Mixing apples with bananas," adjudged County Executive J. Hamilton Lambert.

At one point, Herrity, a Republican, threw up his hands and walked out of the board chambers, only to return moments later to attack Moore anew.

In the end, Moore was on the losing side of a 7-to-1 vote to adopt the county's five-year, $1.6 billion capital improvement program.

Traffic on Fairfax's inadequate roads and the impact of the county's explosive population growth are emerging as two of the touchiest issues the nine board members will face in the November 1987 campaign.

Already, some of the lawmakers have begun trying to etch new images for themselves on the issues of development and traffic.

Yesterday, Moore's detractors argued that the local, state and federal governments had already set aside significant sums to build new roads and expand existing ones.

They said road-building is primarily a state function. Moreover, they said, the state courts have made clear that the county has no choice but to provide enough sewer capacity to keep abreast of new development.

"I don't see how you can legally stop" expanding sewer capacity, said County Attorney David Stitt.

"There is no financial competition at all between sewers and roads," said Supervisor Nancy K. Falck (R-Dranesville). "In fact, when you put state, county, federal and developer money together, there's probably more money available for roads than for sewers."

Moore's colleagues said the county did not have to choose between roads and sewers, but would attempt to provide each with funds.

They denounced Moore's proposal to float general obligation bonds, which would require a referendum, to finance the expansion of sewer plants. Rather, they said they favored financing the sewer expansion through revenue bonds, which would be paid back from hookup charges and would not require voter approval.

Outside the board chambers, Herrity, a longtime opponent of Moore, said: "Audrey Moore has probably isolated herself on the board, which makes her less effective in her district."

But Moore refused to demur.

"We're in a situation now where continuing the pace of development in Fairfax County that you have now just isn't reasonable if you haven't got the roads ," she said.

In other business, the board deferred eight land-use applications because the requests did not include complete disclosure forms. County officials said the deferrals were not exceptional.

But some county board members said they thought staff members had culled the applications with unusual care because of recent reports that board chairman Herrity had failed to report his ties to several developers.