Scientific Investigations Report 2011–5024
The USGS, in cooperation with the Chippewa Subdistrict of the Muskingum Watershed Conservancy District, performed hydrologic and hydraulic analyses for selected reaches of three streams in Medina, Wayne, Stark, and Summit Counties in northeast Ohio: Chippewa Creek, Little Chippewa Creek, and River Styx. This study was done to facilitate assessment of various alternatives for mitigating flood hazards in the Chippewa Creek basin.
StreamStats regional regression equations were used to estimate instantaneous peak discharges approximately corresponding to bankfull flows. Explanatory variables used in the regression equations were drainage area, main-channel slope, and storage area. Hydraulic models were developed to determine water-surface profiles along the three stream reaches studied for the bankfull discharges established in the hydrologic analyses. The HEC-RAS step-backwater hydraulic analysis model was used to determine water-surface profiles for the three streams. Starting water-surface elevations for all streams were established using normal depth computations in the HEC-RAS models. Cross-sectional elevation data, hydraulic-structure geometries, and roughness coefficients were collected in the field and (along with peak-discharge estimates) used as input for the models. Reach-averaged reductions in water-surface elevations ranged from 0.11 to 1.29 feet over the four roughness coefficient reduction scenarios.
First posted March 2011
Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.
Straub, D.E., Ebner, A.D., 2010, Stream profile analysis using a step backwater model for selected reaches in the Chippewa Creek basin in Medina, Wayne, and Summit Counties, Ohio: U.S. Geological Survey Scientific Investigations Report 2011-5024, 78p.
Description of Study Area
Purpose and Scope
Development of Water-Surface Profiles
Analyses of Open Channels
Analyses of Hydraulic Structures
Reduction of Roughness Coefficient Analysis
Results of Hydraulic Analyses
Appendix 1. Descriptions of Benchmarks
Appendix 2. Selected Hydrologic Engineers Center’s River Analysis System Output
for Chippewa Creek, Westfield Ditch, River Styx, and Little Chippewa Creek
Appendix 3. Computed Water-Surface Elevations for Chippewa Creek,
River Styx, and Little Chippewa Creek 57