St. Anthony Falls Hydraulic Laboratory

The objective of this study was the analysis of available rainfall and runoff data for selected watersheds in the state of Minnesota to assist in the evaluation of peak rates of runoff for design purposes. Six watersheds were selected for study. Rainfall and runoff data were analyzed for 51 flood events in five of the six watersheds. AN optimization program prepared by the U.S. Army Corps of Engineers Hydrologic Engineering Center was used to optimize nine variables associated with the watersheds, develop characteristic unit hydrographs, and evaluate loss rates for the watershed in terms of the mathematical model represented by the optimization program. Data on annual maximum floods as well as maximum summer floods were plotted on log-probability paper and theoretical flood-frequency curves determined by the log-Pearson Type III distribution. Approximately 200 figures relating to the rainfall-runoff data and analysis thereof have been included in Appendices for future use. This might involve further work with the same program or possibly other programs. A limited number of copies of the Appendices has been prepared for reference purposes.Water Resources Research Cente