JUST AS SOME people were beginning to think that maybe the District had seen the last of the old plantation days of ham-handed congressional control, there is evidence of renewed colonialism. Not only is a House subcommittee ordering more spending by the city than its elected government had in mind, but it also is handing down a list of things to spend extra money on.

In approving the city's budget request for the fiscal year starting Oct. 1, the subcommittee headed by Rep. Julian Dixon of California drew up a whole set of financial marching orders. One would direct the local government to pay off $15 million more of its long- term debt than it had planned. Another would make the city government continue to pay for street lighting and traffic signals while a plan to transfer those costs to Pepco customers is pending.

Other items were small but irritating: 1) an additional $312,000 to keep a five-person crew on the city's only fireboat; 2) an additional $176,000 and two more jobs for the D.C. Retirement Board; 3) another $32,000 to increase the staff at the Healing Arts Commission (it licenses and disciplines doctors, but hasn't acted in years on a fat backload of complaints); and 4) still another $33,000 and an extra staff job for the National Guard. Money for these, said the subcommittee, should be taken out of the city's budget for interest on short-term borrowings. The subcommittee also wants to require the city to report to Congress on its plans for closing the police and fire clinic at D.C. Village.

It is true that Congress has the authority, one way or another, to make the District grovel for every nickel it wants to raise or spend. But it is neither consistent with the spirit of the home rule charter nor sensible as a matter of financial policy for today's Congress to be intervening in these local matters. To take another case, Sen. Arlen Specter of Pennsylvania, chairman of the Senate Appropriations subcommittee that oversees the District budget, should not be saying he may ask Congress to set up a merit pay system for Washington's teachers; that is a question for the local school board. Such intervention is offensive and it should be resisted by those in the House and Senate who understand the meaning of home rule.