The House voted by the narrowest of margins yesterday to strip 31 water projects from a supplemental 1985 spending bill, despite emotional pleas by many lawmakers to leave their pet projects untouched.

The 203-to-202 vote came after several lawmakers argued that many of the Army Corps of Engineers' 62 water projects were little more than legislative pork barrel doled out to members of the House Appropriations Committee, which drafted the spending bill, and their friends.

Appropriations Committee Chairman Jamie L. Whitten (D-Miss.) strongly argued that all the projects be funded, saying they were "not pork barrel. Those words are 100 years old. When did it get to be bad to look after your own country?"

Rep. Bob Edgar (D-Pa.), who sponsored the amendment cutting the number of projects to 31 and funding from $150 million to $51 million, said the vote showed that most lawmakers for the first time are ready to apply more cost-effective standards to water projects.

The money covers only start-up costs. The cost of completing the 31 projects approved by the House will be about $1.5 billion.

"It was a fight between the old way of doing things and the new," he said. Edgar acknowledged that the outcome could change after the House completes action sometime next week on the $13.5 billion omnibus spending bill for the remainder of fiscal 1985 and goes to conference with the Senate.

Yesterday's cliffhanger vote was partly the product of a turf battle between the Appropriations Committee and the House Public Works and Transportation Committee. Public Works has responsibility for authorizing water projects and is about to draft a major water bill that includes changes in the way projects are allocated and approved. Such changes have been sought for years by environmental groups and successive presidential administrations.

Public Works Committee Chairman James J. Howard (D-N.J.) argued that 31 of the water projects had never been approved by his committee and that to vote to fund them now would circumvent the House committee system.

He said that if the House approved the spending bill with the 31 unauthorized projects, "authorizing committees [such as Public Works] might as well . . . go home, as long as members of Appropriations get their projects funded."

But Whitten and other members, clearly frustrated that Congress has been unable to enact a major water project authorization for nearly 10 years, argued that the House could not afford to wait.

"These projects are needed," said Rep. Tom Bevill (D-Ala.), chairman of the Appropriations panel's energy and water subcommittee. "Most of these projects are flood control. These projects have been studied. Hearings have been held. We were unanimous" on the committee in supporting them. Four Alabama projects were on the list of deleted projects.

Rep. Joe Skeen (R-N.M.), a conservative, said in defense of the Appropriations water projects list, "One man's pork barrel is another man's priority." Skeen, an Appropriations member, had an airport project in another section of the bill.

Among water projects eliminated from the bill by the House vote were: improvements to Eight Mile Creek in the district of Rep. William V. (Bill) Alexander Jr. (D-Ark.), a member of the Appropriations panel; deepening of the Sacramento River deep water ship channel in the district of Rep. Vic Fazio (D-Calif.), another committee member; deepening of the Mississippi River ship channel from the Gulf of Mexico to Baton Rouge, La., a project sought by Louisiana's two committee members, Rep. Corinne C. (Lindy) Boggs (D-La.) and Rep. Robert L. Livingston (R-La.); expansion of Mississippi's Gulfport Harbor, a project of House Minority Whip Trent Lott (R-Miss.); and creation of Parker Lake, Okla. in the district of Appropriations panel member Rep. Wesley W. Watkins (D-Okla.).