By Mary Wisniewski
CHICAGO (Reuters) - There was little the U.S. Army Corps of Engineers could have done differently to prevent the worst of the Missouri River flooding over the summer, an independent panel of experts said on Tuesday.
The panel, which included hydrologists from the U.S. Geological Survey and the National Weather Service, said the flood disaster in the Upper Midwest was "clearly an extreme event with the largest volume of annual runoff on record," according to the report.
Decisions by the Corps' reservoir managers were in line with the agency's Master Manual, its water-control guide, the panel found.
The Missouri River basin includes Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Missouri, Iowa and Minnesota, the Corp said. The flooding washed away interstate highway lanes, swamped rail lines, flooded farmland and forced thousands of people from their homes.
The Missouri River damage followed flood damage done to farmland and other property on the Mississippi River in the spring. The report covers only the Missouri River flooding.
Heavy rains and snow melt in the Northern Plains this spring forced the Corps to release record volumes of water out of its reservoirs, causing historic and persistent flooding.
"Barring an approved change in the Master Manual, the panel does not see how the Corps could have left substantially more storage available leading up to the flood," the panel found.
The Panel recommended support for a program of "infrastructure enhancement" to ensure all flood release spillways are ready for service and all levees are in good condition for future floods.
The panel also recommended a review of the system's ability to store water, and improved future cooperation and collaboration with forecasters.
The report noted that while climate change is not fully understood, given that more extreme runoff events have occurred in recent decades compared to the data on record, the panel recommends reexamining Missouri River System planning based on the entire historical record dating back to 1898.
The report also recommending studying whether the Corps could have greater flexibility "to adapt to varying climatic extremes."
Army Corps Brigadier General John McMahon said the Corps has so far estimated repair costs for river control infrastructure at $630 million as a result of the flooding, and assessments are still being made.
"We have a lot of work to do and a lot of repairs to do," said McMahon, in a joint press conference call with panel members Tuesday.
(Writing by Mary Wisniewski, Editing by Greg McCune)