GLENWOOD, Iowa — The federal agency that manages dams along the Missouri River received stern criticism from several U.S. senators Wednesday during a hearing held in Iowa to examine the massive spring flooding this year that caused more than $3 billion in damage in the Midwest.

The flooding and actions taken by the U.S. Army Corps of Engineers, which has been bitterly criticized in the wake of the flooding, are the focus of the U.S. Senate hearing. Critics have demanded that the agency make flood control its top priority, though Congress would have to act to change the Corps’ priorities.

Iowa Republican Sen. Joni Ernst said flooding shouldn’t be such a regular occurrence along the Missouri River, saying: “The trend of flood and rebuild, flood and rebuild must end.” Democratic Sen. Kirsten Gillibrand added that the Corps should be more aggressive in preventing flood damage and consider the effects of climate change.

“They are too slow, too bureaucratic and they don’t have enough money,” said Gillibrand, who is running for president and was in Iowa touring flood damage. She took part in the hearing because she serves on the committee that oversees the Corps.

The sentiments may be appealing in Midwestern states that have endured flooding along rivers that the Corps is charged with managing, but they may not be as popular with supporters of other approved uses of the river, such as protecting endangered species and navigation.

The Corps’ John Remus said the agency works to balance all the uses of the river and maximize the benefit to several when possible. But flood control is the main concern anytime flooding is imminent along the Missouri River.

“The number one priority of the Corps in its operations is life and public safety,” Remus said.

The Corps has also said that much of the water that caused the Midwest flooding in March came from rain and melting snow that flowed into the Missouri River downstream of all the dams it controls. At the same time massive amounts of water was filling the reservoirs and some had to be released.

Farmer Leo Ettleman said the Corps should have made significant changes to its operating manual after the historic 2011 floods, but neither the Corps nor Congress took action. Ettlemen said the kind of flooding the area saw this spring will continue unless changes are made.