Hydraulics & Waterways
394803 - Revitalization of an urban stream in terms of water quality and recreational usability: assessment of options through hydrologic and hydraulic modeling
Wednesday, June 6
2:00 PM - 3:30 PM
Location: Regency Room
Yeo Howe Lim, PhD
Associate Professor, Department of Civil Engineering
University of North Dakota
Daniel Fife, Grand Forks, North Dakota – University of North Dakota; Grant Neuharth, Bismarck, ND – Federal Highway Administration; Jonathan Olson, Grand Forks, ND – City of Grand Forks; Tom Vidmar, Burnsville, MN – WSB & Associates, Inc.
A stream called English Coulee with a catchment area of 347 km^2 passes through the city of Grand Forks in North Dakota before emptying into the Red River of the North. The coulee has a low head dam located in the upper basin area. Midway through the watershed, the coulee is routed into a diversion channel with two entry points that bypass excess flood discharge around the city. The stretch of English Coulee that passes through the city has stagnation of flow, overgrowth of cattails, poor odor, and deposition of debris and generally poor water quality. As of 2016, the entire length of English Coulee had impairments to human recreation and to the health of fish and other aquatic biota. The causes for these impairments were due to high concentrations of selenium, total dissolved solids, E. coli bacteria, siltation, and low concentrations of dissolved oxygen. A design project to restore the coulee was presented as a challenge to a group of students. The project adapted a hydraulic modeling approach which enabled gauging the effectiveness of multiple design options. The coulee basin’s hydrologic runoff and continuous inflow simulation were developed using HEC-HMS. HEC-RAS was used to model the hydraulic influence of the diversion channel, diversion intakes, weirs, bridges, culverts, and urban reaches. Pertinent survey data for existing control structures was collected. Simulations were carried out to evaluate the effectiveness of four design options consisting of structural controls and channel modifications. Modeling runs showed control modification as the more cost effective solution.