Chicago's 79th Street Tunnel Expansion

"Meeting Future Water Demands"

How can Chicago, Illinois effectively address current and future water needs?

That was MWH's challenge on the 79th Street Water Tunnel Extension Project in this U.S. city. The complex project was honored by the Illinois Engineering Council's "2002 Outstanding Engineering Achievement" award.

The builders of Chicago's original water tunnel system had the foresight to allow for future expansions to serve the metropolitan area's Southwest Station. This made it easier for local officials to address the water demands of future generations, especially to the west and southwest parts of the city.

Award-Winning Project

MWH provided design review services and served as resident engineer for the
US $37.4 million project.

The new tunnel is an extension of the existing 79th Street Water Tunnel, which was constructed in the 1950s.

Located on Chicago's south side, the award winning project extends nearly four miles. It reaches west from underneath the 79th Street right-of-way on Columbus Avenue (Southwest Highway) east to Harvard Avenue.

MWH worked closely with the project team to prevent traffic closures due to construction demands.

Project Features:

• 19,044 ft. of 16’-1” finished diameter concrete lined rock tunnel
• 200 ft. concrete lined variable cross-section rock tunnel
• 22.5 ft. finished diameter gate shaft
• 12.5 ft. wide by 16 ft. high wheel gate
• 25 ft. diameter temporary construction shaft

The tunnel expansion increased the conveyance capacity between the city's South Plant to four pumping stations. It will play a big role in helping Chicago meet present and future water demands.