This levee system was damaged during a 2019 flood event, leading to rehabilitation assistance by the US Army Corps of Engineers. The levee system needed to be repaired to its authorized level of flood risk management.
The approximate length of the bank armoring was 1,300 linear feet. The levee system had slopes of various lengths, from 32’ – 39’. The USACE specified Flexamat® NW-12 with continuous lengths from crest of slope to toe, without seams. The manufacturer supplied a mat layout, showing the custom lengths, with mats numbered from 1 – 85.
The rolls were delivered to the project site, tagged with the specific dimension and with the corresponding mat layout number. Each roll was 15.5’ wide and included a 12” geogrid extension to seamlessly overlap the subsequent mats. The overlap seams were secured in 1’ increments with stainless steel zip ties. The mats extended into the Platte River 5’ beyond normal pool elevation. At the crest of the slope, the mats were recessed into an anchor trench. The installation of Flexamat® was completed in one-week.