Officials of Virginia, Maryland and the District of Columbia have agreed to work together during any future natural gas shortage to avert a repetition of last winter's crisis in which Virginians were harder hit than their neighbors across the Potomac River.

The decision was announced yesterday by Rep. Herbert E. Harris (D-Va.) at a Capitol Hill news conference at which the president of the Washington Gas Light Co., Paul E. Richardt, predicted that the metropolitan area will have ample gas in the coming winterseason.

The agreement is highly unusual, if not unprecedented, in a metropolitan area that shares numerous common problems but seems to find only parochial solutions. In such areas as public financing or mass transit, water supply facilities and sewage treatment plants, area jurisdictions are frequently at odds.

A key element of the new plan calls for treating Northern Virginia as part of Metropolitan Washington instead of as part of Virginia if another gas shortage occurs.

During the severe cold snap last January and February, Virginia Gov. Mills E. Godwin decided to treat all parts of the state identically.

That decision forced many schools and businesses in Northern Virginia to close or curtail operations even though similar customers of Washington Gas Light in the District and Maryland which get their gas from the same transcontinental pipeline - remained open.

Gas-starved communities in downstate Virginia got no benefit at all from the Northern Virginia closures, since most are served be different transcontinental pipelines.

As a result of hearings in April into the gas shortage by Harris' House District Regional Affairs Subcommittee, Virginia Gov. Godwin, Maryland Gov, Marvin Mandel and D.C. Mayor Walter E. Washington agreed to plan for better coordination in the future.

Staff aides reached agreement disclosed yesterday and it will be formally signed next month, Harris said. The agreement contains four points:

A six-member coordinating committee will be created by the governors and mayor to deal with energy emergencies. The comittee will consist of one member each from the state and District energy offices and the state and District public utility regulatory agencies.

In an emergency, the three jurisdictions would ordinarily act jointly on any measures the committee agrees upon. However, recognizing state sovereignity, each state would keep the right to act independently, Harris said.

Counties and cities in the suburbs would be asked for recommendations for dealing with emergencies.

Direct emergency communication would be maintained "to provide a prompt alerting and information-exchange medium" during a crisis.

Harris said Washington Gas Light is preparing to file a new, uniform "gas service curtailment plan" with the three regulatory commissions next month. The plan sets uniform standards for any service reductions that may result from a future shortage.

The Virginia State Corporation Commission already has taken one formal step to permit the entire region to act as a unit, SCC member Junie L. Bradshaw said at the news conference.

That body, which regulates public utility companies, has reclassified 89 major Northern Virginia gas users as "high priority customers," putting them on the same footing as similar customers in the District and Maryland and thus making them less vulnerable to cutoffs.

Of the 89 customers, 20 are schools. The others are chiefly hospitals and nursing homes, but also include hotels and a few businesses.

Reichardt, the Washington Gas president, said his firm expects to be able to withstand any problems in the coming winter without the kind of crisis suffered early this year.

The crisis was touched off when the Columbia Gas Transmission Co., the principal supplier to Washington Gas Light, told customers along its line to curtail their usage of gas.

"Columbia's supply (to us) is the cornerstone," Reichardt said. "We have every assurance, every reason to believe that supply is there (this season)." In addition, Reichardt added, Washington Gas is "chockablock" with reserves of gas already being held in storage.

If there are about normal temperatures this winter, he said gas supplies should provide service to all users through the season. If it is colder than normal, so-called interruptable customers amy be cut off at times, but other users should have an ample supply.

Interruptable customers are generally large users, such as apartment houses, that have the capability of shifting from gas to oil or other fuels in the event of a shortage.

Calling long-range weather forecasting an inexpert art, Reichardt said he expects a winter "colder than normal n but not as cold as last year." Federal weather experts have said they foresee a winter season 15 per cent colder than normal.