Hydraulic Model Study for Homme Dam Safety Improvements Park River, North Dakota

Abstract

This report presents the results of a physical model study of the Homme Dam spillway and outlet channel protection. The objectives of the study were to verify the adequacy of the proposed outlet-channel riprap protection, recommend and verify the adequacy of more economical riprap protection, and determine the spillway rating curve. The model study was conducted for the 8t. Paul District of the Corps of Engineers (COE) at the St. Anthony Falls Laboratory, University of Minnesota. The study used a 1-to-25-scale model of a center section of the spillway and outlet channel. Two outlet channel protection designs were tested. The study showed that the proposed outlet channel protection (Design 1) withstood the probable maximum flood (PMF) without damage to the spillway structure and with only minor damage to the outlet channel protection. A more economical design of the outlet channel protection (Design 2) was proposed and tested; this design withstood the PMF without damage to the spillway and with only minor damage to the. outlet channel protection. The estimated cost savings of implementing Design 2, as compared to Design 1, is $206,000.