Seasonal flooding was a reoccurring issue that stopped traffic over Highway 101’s causeway between Shakopee and Chanhassen, MN. The two-lane causeway ran just a few feet above the flood plain adjacent to the Minnesota River, resulting in frequent flooding and road closures. The solution came when a 4,226 foot-long bridge was constructed nearly 24 feet above the previous causeway. County Prestress & Precast manufactured 369 I-girders for the project, each spanning 102 feet long. The girders were installed in 41 spans, 9 girders per span. The $54 million bridge was a joint project between the cities of Shakopee and Chanhassen, Carver County, Scott County, and the Minnesota Department of Transportation. The new bridge expands the previous two-lane causeway to four lanes and adds a pedestrian and cycling path.
County Prestress & Precast played an integral role in accommodating the project’s accelerated construction schedule. The bridge design called for more than 400 pillars to be pounded through the mucky bottom of the floodplain into the solid ground below. Because the pounding would most likely be loud and unwelcomed in the nearby heavily populated residential area, the city governments wanted the project finished as quickly as possible. The decision was made to follow an aggressive construction schedule using crews working six days a week and late into the evening. CCounty Prestress & Precast accommodated this schedule by delivering materials at all times of the day and each day of the work week.
Longtime residents of the area knew first hand the necessity of having a higher elevation bridge after witnessing major flooding events in 1993, 1997 and 2010. But the flood of 1965 made history when storm water in April peaked at 13 feet above flood stage, well above the roofs of cars. Each of these floods frequently shut down the causeway. With a total of 19,400 vehicles crossing daily, this was a vital roadway in need of an upgrade.
In addition to preventing road closures and adding more lanes, the bridge decreased the environmental impact the causeway had created. Originally, the causeway ran down the middle of the floodplain splitting the area in two. The new bridge spans over the top of the area, allowing for one continuous and connected area for wildlife and the river.
The construction process began in the summer of 2014 and the bridge was completed on November 24th, 2015.
