This is another report on the odyseey of S.790 through Congress.

The Senate yesterday approved legislation that would require commercial barge lines to pay tolls for using federally built and maintained inland waterways.

In a legislative skirmish that pitted a first-term Republican, Sen. Pete V.Domenici (N.M.) against one of the Senate's senior Democrats, Russell B. Long (La.), Domenici prevailed with the argument that "railroads and truckers pay for their rights-of-way and barge lines should, too."

About 16 per cent of the nation's freight is shipped by barge over 25,000 miles of inland waterways built and maintained by the Army Corp of Engineers. The Department of Transportation estimates that federal spending on the waterways is about $1 billion annually.

Since the Northwest Ordinance of 1787, which declared that the waterways should be "forever free," shippers have not been required to reimburse the government for its waterway expenditures.

Yesterday's vote marked the first time that either house of Congress has voted for a waterway fee.

The waterway fee proposal has been introduced in the House, but appears to be making no progress.

Yesterday's Senate vote came to an amendment to a $730 million rivers and harbors bill, which contains several politically popular projects and should pass in the House. When that bill comes to a House-Senate conference, Domenici hopes to add the Senate-passed waterway toll to the conference version, which will go back to both Houses.

However, Long warned that Domenici's strategy might be unconstitutional, citing a clause in the Constitution requiring that revenue bills originate in the House.

In passing the waterway toll plan, the Senate also approved a $421 million authorization for a new lock and dam on the Mississippi at Alton, I11.

The crucial vote in a seven-hour Senate session that was alternately crackling and comatose came when Long and Sen. Adlai E. Stevenson (D-I11.) suggested a study of the toll proposal in the place of the Domenici bill.

The two Democrats argued that too little was known about the impact of a waterway toll on the freight industry and consumer prices to approve it without further study. Domenici and his supporters replied that the idea has been extensively studied and that the Long-Stevenson move was a back-handed method of killing the toll proposal.

The study proposal was defeated on a 51-to-44 vote, and a subsequent Stevenson study plan lost by a larger margin. When those votes made it obvious that proponents of the toll had a majority, support for Domenici's bill grew. The final vote was 71 to 20.

The Senate legislation would empower the Department of Transportation to develop a system for collecting the barge fees. Unless it was rejected by a two-thirds vote in Congress, that system would take effect in 1979.

The long day on the Senate floor was relatively anticlimatic for proponents of the waterway fee, who have been battling in Senate committees and corridors since Domenici proposed the bill in February.

Domenici adroitly maneuvered the proposal through two Senate committees and managed to keep it away from the Finance Committee where Long, a strong advocate of the barge industry, would almost surely have buried it.

The proposal prompted a major lobbying fight between barge interests, who opposed it, and the railroad industry, which backed it, causing a difficult choice for senators in states where both industries operate.

When Stevenson's amendment came up yesterday, for example, Sen. Charles H. Percy (R-I11.) stood at the front of the chamber carefully tabulating the vote. When it became clear that Stevenson's proposal would lose, he voted for it.

That move allows Percy to tell the barge interests that he supported them by voting for the plan and the railroads that he waited until he was sure they would win before voting against them.