Flood information for the Big Creek basin in Linn County, Iowa, should be of use to those concerned with the design of bridges and other structures on the flood plains of the streams. Water-surface profiles for the flood of May 1974 are given for Big Creek and its major tributaries, East Big, Crabapple, Elbow, and Abbe Creeks. The May 1974 flood was at least a 50-year flood on East Big Creek and along certain reaches of Big and Abbe Creeks. Also included for Big Creek are a profile of the December 1971 medium-stage flow and a partial profile for the minor flood of July 1971. Profiles for the low-water condition of October 26, 1972, are shown for all reaches. Water-surface profiles for the 25- and 50-year floods are estimated in relation to the May 1974 flood.