Utah members of Congress began a series of intensive meetings Tuesday, trying to salvage the Central Utah Water Project from defeat at the hands of environmental and public power groups, as well as resolve their own disagreements.

Rep. Howard Nielson, R-Utah, met with Rep. Wayne Owens, D-Utah, for an hour Tuesday to try to work out some of their differences, which have been pronounced and sometimes heated on the issue.Nielson bitterly attacked Owens' approach to the bill last week, and those two needed to make at least a temporary peace, which they apparently did. Owens said the session was fruitful, but there was no definitive resolution.

All five members of the delegation returned to Washington on the same plane, Monday, but did not talk during the trip. They plan to meet jointly on Friday morning with Rep. Morris K. Udall, D-Ariz., to discuss the CUP reauthorization. Udall, chairman of the House Interior Committee, has said the Utahns need to agree on a bill before he will have his committee take it up.

Owens said after his meeting with Nielson that he has permanently shelved his proposed amendments, which would increase the fish and wildlife account from $35 million to $50 million, apply all income from the sale of Utah Lake water rights to fish and wildlife and boost Diamond Fork River minimum flows by tapping Strawberry Valley water. Those amendments drew the ire of Sen. Jake Garn, R-Utah, who had agreed to most of Owens' other requests.

Owens and Garn were to continue their own negotiations Wednesday.

If the CUP is not reauthorized with more money, work on the project will be cut a year from now as it exceeds its legal ceiling. Although funding for the year beginning Oct. 1 is assured, in fiscal year 1990 the project's planned work would cost $160 million, about $60 million more than Congress has authorized, and work would have to be halted before the end of 1990.

The project is caught between environmental groups demanding costly fish and wildlife mitigation projects and public power groups opposing us of power revenues to pay for irrigation and drainage features.

Meanwhile, in the Senate, Sen. Dennis DeConcini, D-Ariz., put a "hold" on consideration of CUP there until opposition of power groups is answered.

Owens called that action "the real death threat to CUP."

He said he thought power groups were stalling over the financing of CUP in hopes that no action will be taken this year.