Sunset Street Bridge
Owner City of Longmont
Lead Design J-U-B Engineers Inc.
Civil & Structural Engineer J-U-B Engineers Inc.
General Contractor Flatiron Constructors Inc.
Portions of Sunset Street and the Sunset Street Bridge in Longmont, Colo., were destroyed during a September 2013 flood. Sunset Street from Boston Avenue to the Burlington Northern and Santa Fe Railroad connects residential neighborhoods to Ken Pratt Boulevard and nearby businesses. In addition, the bridge serves pedestrians for the city’s St. Vrain Greenway System.
The project removed and replaced the damaged bridge with one that’s longer and wider. At 220 ft long and 50 ft wide, the replacement has more room for pedestrians and cyclists, and the new structure is designed to survive a 100-year storm.
As part of the project, designers evaluated the footprint of the bridge and its effect on creek hydrology. Also, Boulder County had to negotiate complex right-of-way agreements in light of the added length and width of the new bridge. The improvements are part of the city’s Resilient St. Vrain, a plan to make the community more resilient during future floods by reducing the floodplain while restoring the St. Vrain Greenway. The bridge reopened to traffic on May 19, 2016.