On the evening of August 17, 2015, an intense isolated storm event came through West Omaha and brought 5 inches of rain in a very short period, producing more water than the 1950’s-era undersized storm sewer could handle. The water drained over the embankment, which was already eroded from overtopping and scouring during typical storms and heavy rains since the storm sewer was initially constructed. This last event was the “final straw” – eroding the embankment to the point that trees caved into the channel below.
This area required immediate attention since the erosion caused a 30-foot drop-off within feet of the roadway on the west side of 108th Street. Hawkins was hired to construct a solution that included a double broken back concept (multiple breaks in grade) for the storm sewer to descend the 40-foot slope.
The team also sought additional ways to prevent future erosion and added these to the project’s long-term solution. Solutions included a new curb and gutter system on the west side of 108th Street and the incorporation of Flexamat, a tied concrete block mat used for high performance erosion control, into the roadway embankment.
The project was completed in just two months, with zero accidents, and no extension despite the rainy autumn weather.
City of Omaha
Diversified Infrastructure Construction & Repair