Here's a 4:37-minute clip from The Great Flood, a documentary by Bill Morrison about the Mississippi River flood of 1927, which put some 27,000 square miles of land under water that in some places was 30 feet deep. The film, currently in release (it premiered in New York City January 8), has no narration or spoken dialogue but its score, by Bill Frisell, is tremendous (I could listen to it again and again). The New York Times reviewer calls the 80-minute feature-length film "visual poetry". Indeed; it is.
The trailer is also on Vimeo.
Internet Archive, Mississippi River Flood of 1927, 1936 Silent Film by Signal Corps
Mississippi History Now, "The Flood of 1927 and Its Impact in Greenville, Mississippi"
PBS, Fatal Flood (American Experience Film) and Timeline (See sidebar for additional educational materials.)
RMS Special Report, "The 1927 Great Mississippi Flood: 80-Year Retrospective" (pdf)
Neil Genzlinger, "Recalling a Disaster Without Uttering a Word: 'The Great Flood' Explores Tragedy on the Mississippi in '72", The New York Times, January 7, 2014
History", The Daily Beast, January 6, 2014
Benjamin Mercer, "Mississippi Flooding: The Great Flood", The L Magazine, January 1, 2014
Stephen Ambrose, "Great Flood", National Geographic, May 1, 2001