Highway 2 Rising For Flood Resiliency
Iowa Department of Transportation says flood impacts will be reduced with highway at higher elevation
By News Channel Nebraska
NEBRASKA CITY – An Iowa Department of Transportation engineer told NCTC’s Hot Topics Wednesday that while there is no such thing as a flood proof road, Highway 2 from Nebraska City to Interstate 29 is moving in that direction.
Floods in 2011 and again this year closed the highway and Interstate 29.
At a time when every bridge from Omaha to St. Louis, Mo., was impassable, the Iowa Transportation Commission designated Highway 2 as a priority corridor.
Yates: “They know just how important this Highway 2 connection is between Nebraska and Iowa and I-29 and anywhere you can go on the interstate system.”
To restore traffic, gravel was used to build up sections of highway that were still flooded in May. That work was washed away, however, by new flooding around Memorial Day that closed the highway until August.
Meanwhile, Ames Construction began work on overflow bridges that would align the levee and increase the elevation of the highway. An eastbound bridge was open to traffic last week.
Yates said the bridge opened ahead of schedule because the contractor was able to skip a plan for a temporary bridge and begin work right away on the permanent structure.
The total project is now scheduled for completion in July of 2020, 17 months ahead of the original plan.
Yates: “Commitment from our entire organization, from our Iowa DOT district office all the way up to the director of the DOT and the governor’s office. They are willing to commit the resources needed and we have a contractor that is able to think outside of the box and do things a little differently.”
The crowd at Scooter’s Coffee was talking futuristically about the flood of 2020, but Yates said there is optimism about travel.
Yates: “We’ve proven through four different floods in 2019 that our number one commitment is to get people moving again and we know everyday counts on both sides of the river. We need to keep interstate traffic on interstates and, regardless of what 2020 has in store, we are ready and willing to help and get people going to where they need to go.”
He said there are also proposals to build a dike that will improve flood resiliency for Highway 2’s interchange with Interstate 29.
Yates said the Highway 2 bridge over the Missouri River was one of five major pinch points in the river system.
He compared the pinch point to a pinch in water hose. The water coming out of the hose is accelerated and water pressure backs up behind the pinch.
Yates compared it to a pinch in a hose, where the water coming out is accelerated and water behind the pinch builds up.
He gave date benchamrks of the disaster and recovery
- March 3 - temperature below zero and a foot of snow at Sioux Falls.
- March 13 - explosive cyclogenesis -- temperature reaches 60 degrees, all snow melts and 2-inches of rain is draining on previously frozen ground.
- March 14 - Platte River blew a hole that was about 3,000 feet long and about 70 feet deep near Plattsmouth.
- March – DOT deployed cameras to survey situation
- April 16 – bridge designer hand sketches levee re-alignment plan that lead to overflow bridge plan
- April 24 - Contractor starts building percolation tracks on flooding segments of Highway 2
- May 9 – Designs available for overflow bridges
- May 10 - Traffic opens after 52 days on one lane with a pilot car
- May 25 – New flooding closes highway until August.
- July 2 – $34 million contract awarded to Ames Construction for overflow bridges.
- Dec. 8 – Eastbound overflow bridge opens to traffic.
Yates said the initial plan was build a temporary bridge by December of 2020. Once the westbound bridge was done, work would begin on a permanent eastbound bridge, which would be complete by December of 2021.
He said the contractor proposes skipping temporary bridge and begin work immediately on eastbound bridge. Project completion is now expected in July of 2020, 17 months ahead of schedule.
Yates said the plan is to raise the elevation by which Highway 2 floods. The elevation of the Horse Creek bridge west of the Sapp Brothers Truck Stop would be the new elevation of the highway. Additional bridges will be built on low spots to achieve that elevation.
There are also options being considered for protections at the Interstate 29 interchange with Highway 2.
One option includes a protective dike around the interchange.
