President Reagan has overruled the Office of Management and Budget to restore most of the drastic 1983 budget cuts the OMB had planned for the Environmental Protection Agency, jubilant sources within the EPA said yesterday.

The sources said administrator Anne M. Gorsuch has won back as much as 80 percent of the personnel and funding reductions that OMB had proposed and that would have further emaciated Gorsuch's already gaunt proposed budget of $975 million.

Senate Environment and Public Works Committee Chairman Robert T. Stafford (R-Vt.) suggested that the verdict might be the first evidence that the administration is backing down from its plans to wring more money out of domestic programs whose proponents already are screeching over 1982 funding cuts.

"Congratulations are definitely in order," exulted a top EPA administrator. After failing to convince OMB Director David A. Stockman in a strongly worded letter and in several face-to-face negotiating sessions, the official said, Gorsuch took her appeal to the president on Wednesday, one of several Cabinet and sub-Cabinet officials to make the trip.

Gorsuch, who argued to Stockman that decimating EPA would boomerang on President Reagan in an election year, is apparently one of the first officials to get a verdict from the White House.

Exact figures were unavailable, but the decision handed down yesterday would appear to tighten the agency belt from the current $1.2 billion to about $916 million instead of the $700 million that Stockman had proposed. The EPA official contended that the $916 million, a 24 percent reduction from fiscal 1982 levels, would still "assure effective regulatory actions" in all fields.

Environmental groups disagreed. "The difference between the Gorsuch cuts and the Stockman cuts is the difference between cutting EPA off at the knees and cutting it off at the hips," said Jonathan Lash of the Natural Resources Defense Council. "The agency will be crippled in either case."

He called the debate over cuts "a cynical little drama," echoing suspicions among EPA critics that the Stockman proposals were really a top-level White House effort to dress up Gorsuch's image as a defender of the environment and a strong presence in the government, and were never intended to stick. Gorsuch had come under heavy congressional attack for her original proposal and had been sharply criticized by some industrial groups for what some called her stiff and uncompromising personal style.

Stafford dismissed the conspiracy theory. "My guess is that OMB has begun to listen to the Congress," he said, recalling statements from Majority Leader Howard H. Baker Jr. (R-Tenn.), a presidential confidant, Sen. Paul Laxalt (R-Nev.), and the Budget Committee chairman, Sen. Pete V. Domenici (R-N. M.), that further domestic budget cuts are unwelcome.

"This could be one of the first signs of that," Stafford said.

At EPA, relief seemed very sincere. The president restored two-thirds of Stockman's personnel cuts and all of the sewer construction grants program of $2.4 billion, which Stockman had cut to $1 billion, the high agency official said. The Superfund program to clean up abandoned toxic waste dumps was given a 21 percent increase over 1982 funding levels, bringing it to a level still about $33 million below the $275 million Gorsuch had requested.

Research and development spending was one of the hardest-fought areas. In her November appeal to Stockman, Gorsuch complained that his 32 percent reduction from 1982 funding would ruin the agency's credibility. She appealed $121 million of the cuts and the president restored 80 percent, or $96.8 million, the official said.