WASHINGTON, Jan. 23 - The White House was told in the hours before Hurricane Katrina hit New Orleans that the city would probably soon be inundated with floodwater, forcing the long-term relocation of hundreds of thousands of people, documents to be released Tuesday by Senate investigators show.

A Homeland Security Department report submitted to the White House at 1:47 a.m. on Aug. 29, hours before the storm hit, said, "Any storm rated Category 4 or greater will likely lead to severe flooding and/or levee breaching."

The internal department documents, which were forwarded to the White House, contradict statements by President Bush and the homeland security secretary, Michael Chertoff, that no one expected the storm protection system in New Orleans to be breached.

"I don't think anyone anticipated the breach of the levees," Mr. Bush said in a television interview on Sept. 1. "Now we're having to deal with it, and will."