The Mississippi River has already exceeded the 1927 flood crest at Memphis. Over the next two weeks or more we will see extraordinary flooding all along the lower Mississippi (and elsewhere).
To facilitate consideration of policy and strategy implications, below are a few links. Please add your own through the comment function.
A collection of relevant public laws by the Walla Walla District, USACE
The Evolution of the Flood Control Act of 1936 by Joseph Arnold on behalf of the USACE, Office of History