LEST ANYONE OVERESTIMATE the amount of local autonomy accorded this city under its 2 1/2-year-old charter, there is a grim reminder this week that whatever Congress giveth, it can easily whisk away. If the Congress accepts a decision made by Rep. William H. Natcher's District pursestring-holders in the House, the entire system of advisory neighborhood commissions in this city will collapse. Tucked in a series of subcommittee permissions and denials in response to the elected government's budget requests is a refusal of any money for the city's 36 advisory neighborhood commissions.

While there's room to argue about just how much money it should take to assist these neighborhood units, the roughly $1 million requested by the District is not so unreasonable as to justify wiping out the whole program with one swipe of the meat ax. Not only did Congress originally approve the establishment of the commissions, but furthermore a solid majority of this city's voters specifically supported the idea in a separate ballot question during the 1974 charter vote. Also, each neighborhood with an advisory commission specifically petitioned for its establishment.

Not all of the neighborhood commissions are successes. In some areas where voting in general has tended to be light, there may be some elected commissioners who either have failed to serve their communities in any noticeable way or have been unable to generate the necessary citizen support for a useful organization. There will be ANC elections this November to address those problems. But, on balance, we think the ANC concept has been taking hold already in a most constructive way.

The elected commissioners are not paid for their work. Under a population formula set forth in the charter, each neighborhood unit has been receiving a specified share of money to cover expenses - amounting to roughly $1 a resident. Much of the money has been going toward newsletters and materials informing residents of city government plans and activities that affect their neighborhoods: streets, zoning , recreation, social services, health, safety, sanitation and so on.

In may neighborhoods, the commissions also are doing a booming business trying to answer all sorts of citizen inquiries and complaints about city services in their areas. Moreover, members of the city council note that the neighborhood commissions also have been providing them with valuable citizen opinion with which to make legislative judgements.

Having said this, we must say that we've not impressed with the need for a special ANC office at city hall at taxpayers' expense, for which funds also have been spent and are being requested again. With proper instructions from Mayor Washington to all city agencies and with specific liaison assignments given to officials throughout the government, city hall ought to be able to communicate properly with the neighborhood commissions - without a special staff.

But the bulk of ANC request - the modest amounts sought to cover neighborhood commission expenses - constitutes a sound investment in hometown management. The ANC's are working to bring local government closer to the people - and in a formative period when local citizens still have a lot to learn about the business of self-government. Their budget requested deserves fresh consideration by the full House Appropriations Committee or reinstatement when the budget comes up for a floor vote. In any event, we hope that sensitivity in the Senate will result in a vote from that body to preserve the ANC system as a useful instrument of good government.