Major Tunnel Projects

The following map details the locations of major tunnel projects. Each tunnel is represented with a different color key. Using your mouse, click on each tunnel for a pop-up window to appear. The new window provides a chance to zoom in on that tunnel area and in many cases you will find an informative fact sheet.

As part of the overall program, construction may also include new sewer lines to convey wastewater, above-ground storage tanks to store stormwater, or deep underground tunnels to both store and convey additional flow during heavy rain events until capacity is available at the respective treatment plant.

All prospective bidders must be prequalified and certified prior to advertisement of these projects. Prequalification is based on past project experience, performance, and financial strength. If you have questions regarding the prequalification process for these projects, please contact Allen Muehlher P.E., Assistant Director of Engineering, at (314) 768-6239 or Kent Kotthoff P.E., Program Manager, at (314) 768-2797.

The following table outlines the key components of each tunnel. The schedule and cost presented is tentative as determined by current planning efforts, and subject to program implementation and final budget approval.

Project (MSD Project No.)	Tunnel Length	Tunnel Diameter	Begin Construction**	Construction Duration	Construction Cost Estimate
Maline Creek CSO Storage Facility (11656)	0.6 miles	28 ft.	2016	Completed	$82.8M
Deer Creek Sanitary Tunnel (11731)	4.3 miles	19 ft.	2017	Completed	$147.8M
Jefferson Barracks Tunnel (11711)	3.5 miles	11 ft.	2017	Completed	$153.4M
Lower & Middle River Des Peres Storage Tunnel* (11820)	9 miles	30 ft.	2029	9 years	$995M
Lower Meramec Tunnel (11746)	6.8 miles	8 ft.	2021	4 years	$212M
River Des Peres Tributaries CSO Tunnel* (12441)	6 miles	18 ft.	2030	9 years	$565M

* Design is underway and the revised schedules are pending approval by the court.
** Dates are estimated and shown in MSD Fiscal Years which start on July 1.