The District of Columbia has been allocated $30 million, Maryland $39 million and Virginia $38 million, of a $4 billion public works-job creation program announced yesterday by Secretary of Commerce Juanita M. Kreps.

The funds will be used to build public building, roads, sewer and water lines, industrial sites, or whatever construction priorities a local government sets. The projects also must receive federal approval.

More important, Kreps said at a news conference, the money will help to reduce unemployment. Local allocations were determined on the basis of unemployment rates and the actual number of persons out of work between March, 1976, and February, 1977.

The program, implemented under the Public Works Employment Act of 1977, is a key element in President Carter's economic stimulus program, Kreps said.

The Commerce Department's economic development administration already has received 22,000 applications for grants to fund local construction projects under the Act. The states will be asked for priority ratings of the proposed works by early June.Selections will be made by the U.S. agency by August.

The federal grants will cover 100 per cent of selected projects, but work must begin within 90 days of grant approval.

Kreps said the program is expected to have "a ripple effect, encouraging private investments in business and property improvements, particularly in urban areas." It also has a "built-in response" to the energy problem by allowing energy conservation projects to be eligible for the grants, she said.

Indian reservations, such "pockets of poverty," as inner-city areas, and projects that were bypassed in earlier public works funding will receive special consideration.

The District received the minimum of $30 million guaranteed to each state. New York received $488 million, the highest allotment. The maximum allocation permitted under the program is $500 million.