The award-winning Jackson Street Corridor project provides a unique aesthetic improvement to a historic area of the Springfield’s downtown, while integrating a substantial stormwater improvement that benefits the entire downtown community. CMT led the design of the one-block stretch of what is to be a much larger corridor that will eventually connect the historic Lincoln Home National Historical Site to the Illinois State Capitol Building.

The city-led Jackson Street project (between 4th and 5th streets) was one of three projects carried out in proximity to each other to coincide with the State of Illinois’ Bicentennial. CMT led the engineering for the other two projects: the renovation of the Illinois Governor’s Mansion grounds, for which Jackson Street serves as a gateway, and the construction of the Illinois Realtors Bicentennial Plaza, which provides a key connection between historical sites and also serves as an adjoining event gathering space. Together, these improvements have created a pedestrian-friendly urban space that enhances the visitor experience for tourists and provide more opportunities for outdoor events in the downtown area.

The project is located within an urban watershed which is served by an 84-inch brick arch combined sewer, constructed in the 1860s, that is susceptible to surcharging as a result of unrestricted urbanized development over the past 150 years. In the planning stages of the streetscape design, it was determined that the location of this project would provide for an ideal opportunity for the city to begin addressing the flooding issue.

CMT modeled various concepts and ultimately decided to begin addressing the sewer surcharging and flooding by installing an underground detention system. The system is located on a portion of the vacant city-owned block immediately north of the Jackson Street project, which was the site of a recently demolished YWCA. A network of 2,300 feet of five-foot diameter pipes was constructed in an 11-foot-deep excavation, designed to hold 340,000 gallons of stormwater at maximum capacity. Packaging the stormwater improvements with the streetscape enhancement.

The street itself was designed with permeable pavers for collecting surface stormwater runoff and infiltration islands at each intersection to collect and filter stormwater runoff from behind the curb.

Other streetscape features included updated ornamental street lighting, power stations for hosting events, and retractable bollards to restrict traffic during events.