The District of Columbia government is planning to spend $850 million over the next six years on new construction and maintenance projects, including the complete renovation of 11 school buildings and six aging public housing projects.

Added to projects already approved or in progress, the new developments would raise the cost of the city's overall capital program to $2.6 billion, all financed by long-term borrowing. By the 1986 fiscal year, the annual cost of repaying the loans would rise from the current $139 million to $244 million. o

The $244 million figure would represent an estimated 13.3 percent of the District of Columbia's total revenue in 1986; that means that more than 13 cents of every tax dollar collected by the city would be used to pay the principal and interest on its construction loans and not for services.

At present, the city's debt-service burden is just over 10 percent of revenues, which is about average for the metropolitan area. A rise to 13.3 percent would put the city near it statutory limit of 14 percent and create an annual drain on operating funds more characteristic of booming suburbs with their new schools, roads and sewers than of older cities. Baltimore's annual debt service is about eight percent, Cleveland's 10 percent.

The "Capital Improvements Program FY 1982-1987" prepared by Mayor Marion Barry's administration says the new borrowing is necessary to improve the city's business climate and to make up for years of neglected maintenance on roads, bridges, water and sewer lines and city-owned buildings. Reflecting the decline in the city's population and in school enrollments, the project proposals emphasize maintenance and rehabilitation rather than new construction or additional capacity. The principal exception is the University of the District of Columbia, where new construction is planned on both campuses.

Most of the proposals are tentative. Only those scheduled to be undertaken in the 1982 fiscal year have been submitted to the City Council. According to the explanatory text accompanying the long-range list, implementation of the other proposals depends on several factors, ranging from the relationship of the city's plans to those of Metro and the Pennsylvania Avenue Development Corporation to the city's ability to borrow the money.

Until now the city has borrowed all its long-range funds from the U.S. Treasury -- an expensive way to borrow because interest rates are several percentage points higher than they would be on tax-free municipal bonds of the kind issued by most cities. The D.C. Home Rule Charter envisions an end to that unique relationship and a shift by the city to the private bond market. The District of Columbia, saddled with deficits and unable to put its financial records in order, has not yet made the switch, but its authority to borrow from the Treasury for new projects is about to expire.

City officials said they expect Congress to extend it for another year, during which the city will complete its preparations for selling its first bonds.

The long-range plan says that priority was given to construction and maintenance projects that would bring in revenue to the city. Others were approved for inclusion if they provide some obligatory or court-ordered service or contribute to the operation of basic facilities or programs. No firm order of priorities is given for the projects overall or within the various city departments, even though the District of Columbia has been reprimanded by Congress for failing to provide such a list.

Highlights of the proposed construction plan include:

Allocation of more than $50 million for modernization and renovation of public schools. On the list are Spingarn, Cardozo and McKinley senior high schools, Kramer, Kelly-Miller, Banneker, Langley and Jefferson junior high schools and Cleveland, Harrison and Parkview elementary schools. j

Major highway projects, mostly financed by federal funds, including reconstruction of the Whitehurst Freeway, completion of the Southeast Freeway at Barney Circle, upgrading Suitland Parkway and the addition of bus and car pool lanes on I-295 to expedite commuter access to the Anacostia Metro subway station. In addition, the city proposes to spend $60 million for road resurfacing and $25 million for bridge repairs.

Complete renovation of some of the city's most dilapidated public housing projects, beginning with Barry Farms and Benning Terrace in 1982. In subsequent years, Stanton Terrace, Highland Addition, Fort Dupont and Greenleaf Gardens would be rehabilitated. Total estimated cost: $62.5 million.

Allocation of $22.2 million to the University of the District of Columbia for construction of science facilities on the Van Ness campus. Another $47.6 million is proposed for construction of buildings on the Mt. Vernon Square campus, but key members of Congress have expressed skepticism about the need for that development.

Construction of a perimeter security fence, emergency entrance, running track, bleachers and shower room at Cedar Knoll, the city's juvenile detention home, for an estimated cost of $2.6 million.

The list does not include the city's biggest project of all, the $98 million convention center, because that already is fully funded and under construction. c