Without debate and after only a brief description, the Senate voted yesterday to approve its version of the District of Columbia's budget for the fiscal year that began Oct. 1.

As approved by a roll-call vote of 70 to 17, the measure provides $1.5 billion for city operations, supported in part by a federal payment of $296 million. It also provides $218 million for city construction programs financed by loans from the U.S. Treasury.

Notable among the 17 who opposed the measure were senators who will move into positions of power in the Republican majority that will take control of the chamber in January. Among them were such lawmakers as Sens. Strom Thurmond (R-S.C.), Jesse Helms (R-N.C.), John Tower (R-Tex.) and President-elect Ronald Reagan's campaign chairman, Paul Laxalt (R-Nev.). None, however, spoke against the bill. Among Washington area lawmakers, only Sen. Harry F. Byrd Jr. (I-Va.) cast an opposition vote. Sen. Charles McC. Mathias Jr. (R-Md.) was absent.

In the dollar level of outlays for city operations, the Senate measure differs little from the version approved last summer by the House. Its passage set the stage for a confrontation between the two congressional chambers over the degree to which Congress should set policy for the city's five-year-old Home Rule government -- notably over the size of the police force.

When a joint Senate-House conference committee meets, perhaps later this week, to work out differences between the two versions, the conferees must decide whether to keep the House's hard-line language that would require the city to maintain a police force with at least 3,880 members or to accept the Senate version that is silent on the matter. Mayor Marion Barry has voiced strong support for the Senate position.

The police force now has about 3,600 members following the abrupt retirment of some 200 officers in August who took advantage of liberalized pension benefits.

Sen. Patrick J. Leahy (D-vt.), chairman of the District Appropriations subcommittee, said the measure was virtually unchanged from the city's request. He said it reflected his panel's decision to end the traditional line-by-line review of the budget in order to give local officials maximum flexibility in managing municipal affairs.

The Senate measure also omits language contained in the House version of the bill that prohibits the use of federal Medicaid money to provide abortions for poor women in the District. Prior to yesterday's action, Leahy said such a provision would be superfluous because federal law already bars such spending, but that he expected House conferees will insist upon such a provision anyway.

The biggest difference between the two versions is in the city's construction program. The city requested $256 million, the House approved $247.9 million and by yesterday's vote the Senate trimmed that to $218 million by dropping the funding for work on the Fort Lincoln urban renewal project in Northeast and several police, fire and transportation department projects.