IT NEVER FAILS: No matter what District officials propose as a local budget, members of the House and Senate make such substantial changes in the request that it sometimes looks as if Congress wanted only to do the city government in. Just the other day, to take the latest example, the Senate Appropriations subcommittee on the District, headed by Sen. Patrick Leahy (D-Vt.), had its round with the city's 1979 budget, following shortly on House completion of its review. Both the House and Senate appropriations subcommittees took significant chunks out of the local budget request. After all of the differences between them are ironed out, city officials will undoubtedly have to plead for more money - like a child begging for a larger allowance.

In some respects the changes the Senate subcommittee made were better than those made by the House; a number of new jobs and a few programs that the House had eliminated were approved. But in other ways, the Senate subcommittee action was much more harsh. Subcommittee members imposed a number of restrictions on the local Comprehensive Employment Training Assistance (CETA) program, recently under attack by the Congress and the Department of Labor, in spite of requests by some local officials to let the City Council be held accountable for cleaning it up.In additional, they turned down a request to increase the federal payment, the money the federal government gives the District to cover the costs of local services - and then went on to make the payment for next year $39 million less than this year's $276 million.

This appalling annual ritual over the budget has the effect of depriving local officials of an opportunity to plan for the future. Which is another way of saying it makes it impossible for them to fulfill their reponsibilities. Those in the District Building simply must wait for congressional approval before figuring out how to make the best of what's left - never mind whether what is left is what is needed. A number of congressmen, when confronted with this aspect of their handwork, reply with the breathtaking non sequitur that since the local budget remains balanced, no real harm has been done.

The harm is that Congress is whipsawing the city. After cutting local items, it usually asks city officials to come up with ways to increase revenue and improve local efficiency. When the city complies - and without increasing local taxes - Congress then cuts the budget again, this time on the federal payment side of the ledger. It is a cruel and erratic way for Congress to discharge its own responsibilities.