1. Delineation of flooding within the upper Mississippi River Basin-flood of June 18 through August 4, 1993, in Des Moines and vicinity, Iowa Yale Public content 1996. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey. English. Public. Iowa, Des Moines Metropolitan Area, and Polk County.