Water Surface Gradations

Water surface profiles show a hydraulic jump within the first 200 feet of the river, likely caused by channel constriction associated with the dam. As ice thickness increases, modeled water surface elevations rise. Thicker ice reduces hydraulic conveyance by decreasing the effective flow area and hydraulic radius beneath the ice cover. To pass the same discharge through a smaller flow area, flow velocity increases, leading to greater energy losses due to friction. These increased resistance losses are accommodated in the model by higher water surface elevations, consistent with  flow behavior observed in real-world systems. 

Cross Section Velocity Distribution Upstream

Ice stability and water flow are closely linked. Higher water velocities can weaken ice by increasing shear stress and mechanical strain, creating thin or unstable areas that increase risk for recreational users. 

The trend of higher water surface elevation with increasing ice thickness persists at the upstream cross section. Across the channel at this location, velocities vary by only 0.8 ft/s from the fastest to the slowest portion, indicating more uniform flow conditions and a more stable ice cover across the river. 

Cross Section Velocity Distribution Downstream

As with the upstream section, the trend of higher water surface elevation with increasing ice thickness persists at the downstream cross section. Across the channel at this location, velocities vary by approximately 8 ft/s from the slowest to the fastest portions. Near the shoreline, velocities approach zero, conditions that promote thicker and more stable ice, while velocities near the channel centerline reach approximately 8 ft/s, where ice is more likely to be thinner and less stable. This strong velocity gradient across the river increases risk, as ice near the banks may appear stable but can rapidly lose stability when traversing toward the channel center.