Washington ? The Army Corps of Engineers announced plans Tuesday to lower Missouri River water levels for three days next week, rather than the full month ordered by a federal judge seeking to protect birds and fish under the Endangered Species Act.

The corps had refused to follow the order to drastically reduce the Missouri’s depth because the agency said it was under a conflicting order from a Nebraska judge to provide enough water for barge shipments.

U.S. District Judge Paul Magnuson, a Minnesota judge who took over the case last month, ruled Monday there was no conflict and the order to reduce water releases remained in effect.

The original order had been issued by U.S. District Judge Gladys Kessler, whose order July 12 cited a period from mid-July to mid-August.

The corps ordered barge shippers to secure their vessels for a period of low flows from Aug. 12 through Aug. 15 that would make the river too shallow for navigation. The directive apparently interprets Kessler’s order only as ending mid-August — and not as comprising a full month, starting whenever the low flows begin.

Conservation groups that won the injunction were angry at the corps’ announcement.

“Who do they think they’re fooling?” said Eric Eckl, a spokesman for American Rivers, the lead plaintiff. “Three days? It’s hard to imagine that such a very limited period is going to have any appreciable effect. This is an act of bad faith.”

A spokesman for the Justice Department, which is representing the corps, said Tuesday that attorneys were discussing their next course of action. Justice attorneys plan to ask Magnuson today to renew a stay of the order for less water.

The corps was cited for contempt for disobeying the order, but Magnuson delayed the contempt finding and resulting fines of $500,000 a day. He said a higher court, the 8th U.S. Circuit Court of Appeals, was expected to rule Aug. 27, and he scheduled a status conference in his court for Sept. 8.

At issue is whether the Endangered Species Act takes priority over shipping and other uses of the Missouri.

Conservation groups want the Missouri to ebb and flow more naturally to encourage spawning and nesting to protect shorebird and sturgeon on the government’s list of threatened and endangered species.

Barge and farming interests say the corps has a legal obligation to provide enough water for barges.

The corps said last month the flow reductions would drop depths at Kansas City, Mo., from about 14 feet to 8 feet, which is too shallow for barges carrying grain and other cargo to the Mississippi River.