The House yesterday approved a pared-down version of the Garrison Diversion Project, a federal irrigation plan in North Dakota at the center of controversy for decades.

Approval, on a 254-to-154 vote, came after a 203-to-199 defeat of an amendment that would have required farmers benefiting from the project to pay full costs for water used to grow crops now in surplus. The amendment was offered by Rep. Berkley W. Bedell (D-Iowa).

Yesterday's vote was a major hurdle for the Garrison project, promised to North Dakota four decades ago as compensation for the loss of a half-million acres of prime river bottom land to a Missouri Valley flood project but bitterly contested on environmental and economic grounds.

In 1984, Congress set up a commission to reconcile the differences among North Dakotans, environmentalists and Canadian officials, who feared that the project would flush "trash fish" and pollution across the border in violation of an international treaty.

The project approved yesterday incorporates most of the commission's recommendations, nearly halving the project's original $1.2 billion cost and eliminating the interbasin transfers that concerned Canada.

Environmentalists were particularly concerned about the thousands of acres of wetlands that would be destroyed by the project, threatening breeding areas for migratory birds.

According to National Audubon Society official Ruth Norris, the project now requires the Bureau of Reclamation to restore or protect an acre of wetland for every acre destroyed. A "wetlands trust" also would be established, funded by the federal and state governments.

A compromise between environmentalists and developers made House approval of the project almost a foregone conclusion, but the support garnered by the Bedell amendment came as a surprise.

Lawmakers, particularly from the agriculturally depressed Midwest, have become increasingly critical of the irrigation subsidies that have enabled western growers to outproduce their midwestern brethren in traditional grain and forage crops.

The Garrison project had become a case in point. Its water will irrigate 130,000 acres of wheat and potatoes, both of which are in oversupply.