In 2019, Iowa experienced the wettest January to May period on record. Flooding and the resulting damage closed IA 2 at the Missouri River bridge near Nebraska City. Iowa Governor Kim Reynolds challenged the Iowa Department of Transportation to realign the levee and elevate traffic on a new bridge to increase river overflow conveyance and improve the resiliency of the IA 2 corridor before spring 2020, less than a year away.
The re-aligned levee and bridge construction was completed ahead of schedule. Dual 1,100-foot x 40-foot bridges were designed in just nine weeks and the first bridge was constructed and open to traffic on IA 2 less than six months after contract letting. Stanley Consultants was the design engineer and engineer of record for the expedited bridge design.
Reconstructing a constriction in the levee system was identified as a potential improvement that would increase conveyance by opening the floodway. This was accomplished by raising the roadway and pushing back the U-shaped levee. This provided room to realign and straighten the levee, allowing water to flow straight past. The new bridges were constructed to carry traffic over the river overbank.
In April 2019, the main objective was established that the first bridge be open to traffic and the levee realigned, allowing the river conveyance to be open to flow by March 1, 2020. The first bridge was open to traffic in December 2019 followed by opening the river overflow conveyance before the end of 2019.
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