With the present session of Congress slipping away, prospects for reauthorization of the Central Utah Reclamation Project teetered on the brink this week. A last-minute hitch in the House Rules Committee threatened to push CUP over a congressional precipice.

Adding to the woes of CUP is a last-minute reappraisal by the Bureau of Reclamation of the cost of finishing the big water project. Estimated earlier at about $686 million, the cost has jumped to about $900 million after the bureau "found" $214 million in costs it says must be included.Congressional leaders are aiming at adjournment Oct. 19, just three weeks before the Nov. 6 elections. That leaves two weeks to wrap up a raft of "must" measures including the controversial budget deficit reduction package. Legislation, including CUP, that has made it most of the way through the congressional labyrinth will die unless all action is completed and it goes to President Bush before the end of the session.

Congress could return for a lame duck session after November, but the leadership of both parties want to avoid such a meeting - almost at all cost.

The problem Thursday was a section added to the CUP bill by Rep. George Miller, D-Calif., to reform the entire reclamation program, including new stiff limitations on the acreage that a farmer can irrigate with federal water, and other changes strongly opposed by many members from reclamation states. Enough members of the House Rules Committee oppose the Miller plan so that the committee has refused to approve CUP as long as it carries the reclamation provisions.

Rep. Wayne Owens, D-Utah, sought this week to get the House Democratic leadership to schedule CUP for a vote even without approval from the Rules Committee, but as of Wednesday night he had not been successful. An Owens aide said the Salt Lake congressman hoped that if the billwere scheduled without a rule, the Rules Committee might relent and grant it one.

Without approval of the Rules Committee the CUP bill would be subject to points of order which could kill it and attempts to strip away the Miller acreage limit provisions.

The measure could hardly be coming up for a vote at a worse time, with Congress locked in a bitter dispute over cutting the deficit. CUP's $900 million price tag is likely to attract opposition from members under strong pressure to cut spending and avoid the tax increases included in bipartisan deficit-cutting agreement.

In the Senate, Sen. Jake Garn, R-Utah, said this week that he and Sen. Bill Bradley, D-N.J., chairman of the Senate Water and Power Subcommittee, were close to working out agreements on final details of the CUP bill. Garn conceded that there probably will not be time to get approval of the bill in the Energy and Environment Committee, leaving the measure to be dealt with by amending a House-passed version.

Unless the Senate changes can be put into the House bill on the floor, the House would have to vote on the bill yet again, or it would have to go to conference.