TO MORE THAN 1.3 million Americans, the public housing system is an invaluable resource. Itsresidents are among those least able to afford housing on the private market. While much of the debate about subsidized housing focuses on tenant ownership or on the best ways to meet low-income housing needs in the future, a problem is being ignored. The existing stock of public housing, according to a recent report by the National Housing Law Project, is being threatened by a combination of neglect, abandonment and demolition.

In a survey of more than 3,000 public housing authorities, the National Housing Law Project found that more than 15,000 units of public housing have been lost within the last 10 years. The pace is also accelerating, up from 825 lost units in 1980 to about 3,500 per year by the end of the past decade. Moreover, the Housing Law Project says that another 30,000 units are being considered for demolition or sale and 20,000 more "are now in jeopardy, or soon will be. ... Without question, more public housing units will be demolished or sold nationwide than will be added to the public housing inventory."

Subsequent plans for demolition, sale or disposal are supposedly subject to approval and oversight by HUD. However, the report's authors say that "meaningful HUD oversight does not exist" and units which could have been renovated and preserved are being lost. A "thinning" of housing projects through partial demolition accounts for a majority of all lost units.

The process generally begins through neglect. Routine maintenance is postponed, repairs are not done, security declines and vacancies slowly climb. In some cases, the local housing authorities have failed to use modernization funds from HUD, or have not even applied for them. Living conditions deteriorate, and vacant units are left unrepaired. What's needed is a better system of preventive maintenance. The decision to sell or demolish public housing must also be closely scrutinized, both by HUD and by local elected officials. Sale or demolition should be prevented unless absolutely necessary.

The Housing Law Project has come to the defense of a discredited horse. The federal government has largely removed itself from the creation of new units, and the public's view of such housing has been tainted by stories of mismanagement as well as the desperation of tenants who live in decayed, vandalized and crime ridden projects. But public housing still fills a critical gap, particularly for those families who would have to pay 50 percent to 70 percent of their meager incomes on housing in the private market. It is a resource that must be preserved.