Poor planning and confusion about the military's role contributed to problems after the storm struck on Aug. 29, 2005, and without immediate attention improvement is unlikely, the Government Accountability Office said Monday.
It urged the Defense Department to establish procedures to speed aircraft, troops and reconnaissance gear to hurricane-stricken areas when local and state officials are overwhelmed as well as beef up communications support to Homeland Security officials, who have the lead role in a disaster.
"The devastation of Katrina and the issues it revealed serve as a warning that actions are needed," said the report by Congress' investigative arm. "Without urgent and detailed attention to improve planning, the military and federal government risk being unprepared."
Responding to the study, Assistant Defense Secretary Paul McHale said the Pentagon has taken several steps to improve its disaster response.
In recent weeks, defense officials have stocked up on cellular and satellite phone vans, begun updating their emergency response plans and have placed specially trained military personnel into the Federal Emergency Management Agency regional offices.
"Striking the appropriate balance between the military's primary warfighting role overseas and the need to support civil authorities at home is a difficult but fundamental issue," McHale said in a letter included with the report.
The report said the Pentagon had ample warning since 1992's Hurricane Andrew, which devastated swaths of South Florida, of problems relating to communication and allocation of resources. Among the problems:
Few of the government's pre-Katrina disaster response exercises focused on catastrophic natural disasters. None called for a major deployment of Pentagon resources.
The Pentagon did not have procedures to step in with troops and other reconnaissance to assess the amount of damage in coordination with state and local officials.
The military did not plan for integrating large numbers of deployed troops serving under different commands such as the federal government and various states.
"No one had the total picture of the forces on the ground, the forces that were on the way, the missions that had been resourced, and the missions that still need to be completed," the GAO said. "Substantial improvement will require sustained attention from the highest management levels in DoD, and across the government."
The report comes as the Bush administration contemplates the proper domestic role of the military as it faces long-term obligations in Iraq.
Previous White House and congressional investigations into the Katrina response have said the military should take on a greater role. President George W. Bush also is considering plans to shore up the Mexican border with National Guard troops paid for by the federal government.
During investigations into last year's hurricane response, FEMA and the Homeland Security Department took much of the criticism, leading to the resignation of FEMA chief Michael Brown.
"The key to a successful response for DoD and others is to create detailed plans for the response, train personnel on those plans, and simulate our response with detailed exercises," Sen. Joe Lieberman, a Connecticut Democrat, who sits on Senate Homeland Security Committee, said in an e-mailed statement.
The report notes that in the unprecedented disaster that Katrina caused, the Pentagon responded with 50,000 National Guard and 20,000 active federal personnel for search-and-rescue missions.
It also was given the difficult task by FEMA of distributing ice, water, food and medical supplies and, as a result, had to airlift 1.7 million meals to Mississippi at the last minute because FEMA did not have an adequate system to keep track of what was ordered.