President Carter won a narrow victory yesterday as the House Budget Committee voted to cut from the 1978 budget $280 million for water resources projects the administration wants to kill.

Over the objections of Majority Leader Jim Wright (D-Tex.) and Chairman Robert N. Giaimo (D-Conn.), nine Democrats and four Republicans joined to vote for the $280 million funding cut proposed by Rep. Butler Derrick (D-S.C.)

In the budget he proposed last month, Carter deleted $289 million in funds for 19 ongoing water projects that had been in the budget President Ford sent to Congress in January. An irate Senate voted on March 10 to reject the administration plan and oppose any cutoffs; the biggest legislative setback the new administration has received.

Since then, the President has restored three of the projects and added 14 new ones to his so-called "hit list." The 30 projects on the list could cost the federal government as much as $530 million in the federal spending year beginning Oct. 1, but the administration has not said it will necessarily seek to stop all 30.

Giaimo had sought to boost spending for water projects $360 million over Carter's level of $4.64 billion. By a 13-to-11 vote the committee trimmed Giaimo's proposed boost by roughly the amount requested by Carter on Feb. 22.

While Carter won a victory yesterday on the water projects, the Budget Committee, again over Wright's objections, voted to trim $2.3 billion from the $111.95 billion the President wants to spend on defense in fiscal 1978.

The committee, again on a 13-to-11 vote with all eight Republicans voting no, adopted the spending level proposed last week by Chairman Giaimo, $109.65 billion.

Giaimo resisted Republican attempts to spend the full amount recommended by Carter and also defeated a compromise proposed by Wright that would have cut Carter's defense budget by $1.1 billion rather than $2.3 billion.

The committee also narrowly defeated a proposal by Rep. Jim Mattox (D-Tex.) to cancel funding for the controversial B-1 bomber as of May 1, 1977 - a move that would have reduced the defense budget by $800 million next year.

While decisions by the Budget Committee on particular programs are not binding - and the overall spending targets set in the spring are targets not binding ceilings for congressional appropriations - the surprise vote to back the President on the water projects should strengthen his hand in dealing with Congress on the matter.

The Congress must approve a tentative budget for fiscal 1978 by May 15 and must approve a binding budget by Sept. 15. Any appropriation that would push overall spending above the level adopted by Sept. 15 is out of order in both the House and the Senate.

Wright opposed the Derrick amendment, noting that Congress had approved all the projects, which are in various stages of completion, and that the President's advisers cannot change the criteria on which the projects were approved.

"If we knock out the money, we'll be making an assumption the President isn't even making," that the projects will be canceled, Wright said.

As part of his pledge to balance the federal budget by fiscal 1981, Carter said he has subjected 337 water projects to new environmental, economic and safety criteria and approved all but 30 of those projects under the new standards.

Derrick said that by deleting only $280 million, not the full $530 million that would be saved if all 30 projects were canceled, he left flexibility to both the administration and Congress.

Giaimo has proposed a fiscal 1978 budget with deficit of $62.4 billion - on spending of $460.6 billion and revenues of $398.2 billion.President Carter on Feb. 22 proposed a budget that assumed $401.6 billion in revenues, $459.4 billion in outlays and a deficit of $57.8 billion.

The House committee expects to complete work on its tentative 1978 budget Wednesday and the Senate committee will start work later this week.