Northern Virginia lawmakers say they are bracing for one of the toughest money wars in the history of the state General Assembly.

They expect to spend the next two months scrounging for money to finish the Metrorail, build new roads and plug the holes in education and health programs left by federal cutbacks.

"It will be quite frantic," Del. Floyd C. Bagley (D-Prince William) said of the 1982 session that opened yesterday. "The overriding issue relating to Northern Virginia will be that we will have to find the money . . . for essential programs and not increase taxes."

And while the scramble for dollars may fuel old rivalries between regional delegations, it also may draw the frequently fragmented Northern Virginia delegation closer together.

"I think that Northern Virginia is more united than ever this year," said Sen. Charles L. Waddell (D-Loudoun), "especially on the issues of Metro and highway funding for this region of the state."

Sen. Wiley F. Mitchell (R-Alex.) said he feels that, in the Senate, "on issues that affect Northern Virginia, most of us manage to hang together." But he added, "I don't think you can predict what the House of Delegates will do . . . though there is every indication that we will be able to work together at least as well and maybe significantly better than in the past."

There's also hope that, as governor, Charles S. Robb will be sympathetic to Northern Virginia concerns, said freshman delegate Marian A. Van Landingham (D-Alex.) "Also, I think it's good that Robb has appointed two Northern Virginians to primary positions: Wayne Anderson as secretary of administration and finance and Joe Fisher as secretary of human resources," Van Landingham said.

Although most nonfinancial issues will be shoved into the background during this year's session, Northern Virginia legislators say they still expect to wrestle with such local issues as housing, condominium conversion and land use.

But funding for Metrorail and highways will dominate most of the Northern Virginia legislators' budget bouts, according to Sen. Adelard L. Brault (D-Fairfax), chairman of the 29-member delegation.

Metro funding has been threatened on two fronts: State money would be cut by more than a third of last year's amount under current administration budget proposals, and federal authorities have warned that they may withdraw funds unless Virginia finds a more "stable and reliable" way of financing its share of Metro's operation.

Congress has funded a substantial portion of Metro construction costs to date, with the provision that local governments find adequate revenues to operate the system. In Virginia, most of that money has come from a 4 percent regional gas tax imposed by the 1981 legislature. If the federal government considers the local aid base unstable, however, it can withdraw the federal subsidy.

U.S. Transportation Secretary Drew Lewis recently cautioned Virginia that the regional gasoline tax--charged in Fairfax, Arlington, Alexandria, Falls Church and Fairfax City --is too small to cover Northern Virginia's share of running the system. Lawmakers said gasoline consumption in the state has leveled off in the past several years and, as a result, income for Metro has not increased enough to meet rising operation costs.

"There is going to be a lot of struggling," said Del. John Rust Jr. (R-Fairfax). "There's an awful lot of talk about going to a different type of gas tax because we are faced with declining gas usage." Rust and others said the General Assembly may be forced to consider raising the gasoline tax or turning to alternative regional taxes, such as higher sales taxes, to supplement the share of Metro funds that now comes from the gasoline tax.

"We could consider adding 1 cent to the sales tax in each jurisdiction [served by Metro]," said Brault, who was unsuccessful in his attempt to push through similar legislation two years ago. But the proposal is expected to be reconsidered this year, he said.

Legislators agree that a cut in both state and federal funds could cripple plans for completing the Metro system in Northern Virginia.

"One of the most important priorities in the whole Northern Virginia delegation is to restore the full amount of Metro funding and hopefully get it increased to reflect increased costs," said Mitchell.

The local delegation also is worried about Northern Virginia's share of money for highway construction and repair, said Rust. "From a regional perspective," he said "we have more crying construction needs than other areas of the state."

But there will be tough competition for highway dollars. The Department of Highways has warned that the state will run out of road construction funds by 1984, Rust said. The state also faces cuts in federal highway money.

Although rapidly growing areas of Fairfax, Loudoun and Prince William counties would be hit hardest by cutbacks in new highway construction money, the entire region would be hurt by what lawmakers said has been described as a dwindling road maintenance fund.

"We have to find a way to prevent one of the finest highway systems in the state from deteriorating into shambles, which it will soon if we do not address the problem." said Sen. Waddell.

Del. Dorothy S. McDiarmid (D-Fairfax) predicted the Northern Virginia delegation may be forced to make trade-offs with other delegations to win money for both Metro and highway construction. But, conceded Rust, "I don't think we will convince the rest of the state we need more than them."

Although transportation issues lead the legislators' financial concerns this year, many local lawmakers also have spent the past few months listening to pleas from elderly, handicapped and mental health organizations. These groups are looking to the state to help maintain their services because of recent and proposed cuts in social services by the Reagan administration.

"The cuts in human services are going to be really tough," said McDiarmid, who is the chairman of the House Appropriations subcommittee on human services.

"There is grave concern about the federal cuts as they may affect human services, including the physically and mentally disabled and the elderly," said Waddell.

"Most of the concerns that I hear about are about Medicaid," said Sen. Charles J. Colgan (D-Prince William), "with the tightening of the requirements to meet Medicaid qualifications."

Del. Mary A. Marshall (D-Arlington), a longtime advocate of programs for the elderly, said her subcommittee on long-term care for the elderly is conducting a study "to assure that people who can't live alone get the care they need and are not put in nursing homes if they don't need to be in nursing homes."

"The Medicaid budget is breaking every state," said Marshall, adding that she feels the issue is of paramount importance and that she plans to work for legislation to reform the Medicaid system. "We are going to try to make Medicaid pay for anything you need," she said. "Not like the present system, where you get nothing but nursing home [care]."

Education

Federal budget cuts also are expected to strain the state budgets for elementary, secondary and higher education. School boards throughout Northern Virginia want the delegates to push for greater state contributions to their school systems. In the current year, the state's share of Arlington's school budget is 14.7 percent; Alexandria, 16.3 percent; and Fairfax, 27.7 percent.

The two largest colleges in the Northern Virginia area--George Mason University and Northern Virginia Community College --also may feel the brunt of cutbacks in state spending for new construction.

"That's an area where I foresee a lot of fights and problems," said Rust. "The colleges in the rest of the state are already built up, but our two universities are still growing. Now there's a possibility that growth will slow down because of budget cuts ."

Requests from local school boards also include opposition to any laws that would reduce the compulsory school attendance age from 17 to 16 or that would require full-day kindergarten programs. School officials also would like higher fines against parents whose children vandalize school property and stiffer penalties for drug sales on school property.

Del. James H. Dillard (R-Fairfax), who works in the Fairfax school system's alcohol and drug abuse program, said he will introduce a package of six bills intended to toughen drug sales laws. One proposal would make the penalties for selling drugs on school grounds stricter than those imposed on persons convicted of selling drugs in other places.

"We want people to know that if they come on school grounds and get caught, they will be zapped," Dillard said.

Housing

Another major issue confronting local lawmakers is the dwindling supply of low- and moderate-cost rental housing because of conversions to condominiums and cooperatives.

Del. James F. Almand (D-Arlington), the key author of housing legislation for the Northern Virginia delegation, said he and his colleagues plan to sponsor several bills aimed primarily at easing the depletion of such rental properties. Although the bills won't prevent conversions, they should "provide more protection for tenants," Almand said.

The governing bodies of Arlington, Alexandria and Fairfax County--where displacement of elderly, disabled and low- and moderate-income persons appears to be most acute--have asked their delegations to propose a series of measures to preserve the rental housing stock.

Almand says he and his colleagues plan to introduce bills requested by Alexandria and Arlington to provide tax incentives for rental property owners to sell directly to tenant associations and to give tenant groups the first option to buy their building.

According to Almand, bills also will be introduced governing apartment building conversions into cooperative units, an area now virtually unregulated by the state, making some of the consumer protection laws governing condominium conversions also apply to cooperative conversions. A related bill would give tenants the first option to buy their units.

Another bill Almand said he intends to introduce would allow localities to use funds to help owners of rental apartment buildings rehabilitate their units in return for keeping the buildings rental and setting aside some units for low- and moderate-income renters.

Equal Rights Amendment

Another issue that has filled legislators' mailboxes with constituency comment in recent weeks has been the Equal Rights Amendment. This session will be the last chance for the state legislature to act upon the amendment under existing deadlines.

The Northern Virginia delegation traditionally has given the ERA some of its strongest legislative support. But even the staunchest ERA backers predict it has only a slim chance of passing the Assembly this year.

"The ERA continues to have an uphill fight in Virginia," Del. Vincent F. Callahan Jr. (R-Fairfax) has said.

Drunken Driving

The problem of drunken driving also is on the legislative agenda of several Northern Virginia lawmakers.

"I think I have to do something about drunk driving," said Prince William's Bagley. Sen. Edward M. Holland (D-Arlington) also said he has gotten a lot of mail on drunken driving and plans to propose a task force on the problem, which he said is "turning automobiles into flying bombs."