Canada expressed new concern yesterday over two North Dakota senators' efforts to win more construction money for a controversial irrigation project near the international boundary.

Government officials in Ottawa prepared a diplomatic note for delivery to the State Department today, voicing new objections to the $835 million Garrison Division Projects in North Dakota.

Ambassador Peter M. Towe also was instructed to contact congressional leaders, as he has done in the past, to register Canada's concern over Garrison, sources in Ottawa reported yesterday.

Canadians fear that diversion of Missouri River water through a system of lakes and canals into their Hudson Bay drainage basin will create serious environmental and economic problems in Canada.

Garrison has been stalemated since 1977, when the U.S.-Canadian commission that oversees a 1909 boundary waters treaty recommended against continuing the project until the two goverments consulted.

Those consultations have not occurred, but the project took wing again Tuesday when a Senate Appropriations subcommittee added $9.7 million for Garrison construction to its 1980 supplemental money bill.

The subcommittee acted at the behest of its two North Dakota members, Republican Milton R. Young and Democrat Quentin N. Burdick, both long-time boosters of Garrison.

Amid the new controversy, the full Appropriations Committee is expected to take up the Garrison funding matter today. Opponents of the project, led by the National Audubon Society, have little hope of reversing the subcommittee action.

But the House supplemental appropriations bill contains no money for Garrison and the Carter administration, under pressure from critics here and in Canada, has declined to move ahead with the project.

As authorized, Garrison would take alien fish species and parasites, as well as pesticide runoff and chemicals, into the Hudson Bay drainage basin and threaten Canada's sizable fishing and tourist industry in Manitoba.

The Manitoba government, backed by the national government in Ottawa, contends that Garrison carries "disastrous implications" for Canada.