Using the environmentalists' trusty weapon - the environmental impact statement - California farmers are seeking to overturn proposed regulations that would break up large corporate farms in federally irrigated areas.

Attorneys for three counties and three water districts in California said they will file suit this week in U.S. District Court in Fresno, to force the Interior Department to prepare an environmental impact statement on its "excess lands" regulations.

The proposed regulations, issued in August to enforce the long-ignored 1902 Reclamation Act, would require Western farmers to sell any federally irrigated land in excess of 160 acres per person and to live within 50 miles of their land.

If interior is forced to prepare a voluminous impact statement, final regulations could be delayed more than a year. In the meantime, opponents hope Congress will change the 1902 law.

The California case is the latest incident in what is fast becoming a national trend. Business interests, who for years have seen environmentalists kill their favorite projects by demanding impact statements, are now turning the tables.

The National Chamber of Commerce recently filed suit against the administration seeking an impact statement on President Carter's proposals for parks and wilderness areas in Alaska.

A few weeks ago, North Dakota attacked Carter's plans for a national water policy by asking a federal court in Bismarck to require an environmental impact statement. Similar tactics have been attempted by opponents of federal strip-mine legislation and the Panama Canal treaties.

"What's good for the goose is good for the gander," said Daniel Beard, an Interior official who handles excess lands. "It's a flip-flop.Development groups are using the environmental impact statement to prevent the department from proceeding" with environmental reforms.

"We've kind of switched roles," said James Lake of California Westside Farmers, which opposes the regulations. "The environmentalists are the ones in power now and the very people who used to fight for environmental impact statements are the people who wrote the regulations saying they don't have to."

Interior claims a detailed environmental impact statement is unneccessary because the environmental effects are "probably insignificant" and the regulations merely reflect existing law." However, after 74 senators and members of Congress recently requested an impact statement.Interior decided to prepare a preliminary assessment by Febraury, reconsideing the issue.

The man who originally decided that no statement was needed was Assistant Solicitor John D. Leshy, well-known to Californians in his previous role as an environmental lawyer.

Raymond Momboisse, a lawyer for the Pacific Legal Foundation, which is filing suit against the regulations, said, "I've been up against Leshy (in court) when he has strenuously argued in favor of an environmental impact statement. Now I can quote his arguments and he can quote his arguments and he can quote mine.

Momboisse said the regulations will have "a tremendous impact on the environment, Kings County alone will have to build $21 million worth of roads."

But Momboisse, while insisting he is serious in his concern for the invironment, couldn't help joking when he broached another issue. "Are you ready for this one?" he asked, explaining that the regulations would affect two endangered species, "the blunt-nosed leopared lizard and the San Joaquin kit fox."

Kings, Fresno and Imperial counties, the California water districts of Westlands. Kern Tulare and Cawelo, individual farmers and Jackson County, Okla., are expected to join the suits.