Colsman Tunnel Rehabilitation Project

Our apologies in advance for the annoyances that come with construction and we thank you for your patience and cooperation while we rehabilitate critical infrastructure to protect health, safety, and the environment in your neighborhood!

Schedule Update (12/6/18)

The contractor continues to prepare the east and west portals to begin pipe pulling operations ("sliplining").  Sliplining operations are scheduled to begin the week of December 17th, and continue through February.  In order to minimize schedule delays from the holidays, the contractor will be working Saturdays in December.  They will not work Christmas Eve, Christmas Day, New Year's Eve, and New Year's Day (unless there is an emergency).

Project Information:

Location E. Orchard Road, between S. Jackson Street and S. Cherrywood Circle
Greenwood Village/Centennial
Description Rehabilitate an existing 1.5 mile long sewer tunnel 
that serves the entirety of Southgate Sanitation District to protect public health, environment, and safety, and ensure its long-term adequacy, function, and reliability
Estimated Cost $15.5M
Owner Representative Burns & McDonnell Engineering Company, Inc.
Design/Build Team
Garney Companies, Inc.
Dewberry Engineers, Inc.
Shannon & Wilson, Inc.
Schedule October 2018 – May 2019 for tunnel rehabilitation work at the west portal
October 2018 – November 2019 for tunnel rehabilitation work and site improvements at the east portal

Project Description:

We are rehabilitating an existing 1.5-mile long sewer tunnel by pulling a new, 48-inch diameter plastic pipe through the tunnel. The new pipe is made of high density polyethylene (HDPE) and the joints will be fused together, making it one solid piece of pipe through the entire length of the tunnel. The contractor must set-up work sites at two locations to pull the pipe in place – one at the entrance of the tunnel and the other at the exit of the tunnel. One work site (the “east portal”) will be located at Southgate’s offices near E. Orchard Road and S. Jackson Street. The second work site (the “west portal”) will be located on the south side of E. Orchard Road between S. Ogden Court and S. Humboldt Court.

The new pipe will be fused together and fed into the tunnel at the west portal. The pipe will be pulled through the tunnel by a machine located at the east portal. Once the new pipe is in place, grout will be pumped into the tunnel to fill the empty space between the new pipe and the tunnel wall.  Thereafter, the contractor will reconstruct the portals and clean-up and restore the work sites.

We anticipate the areas located around the portals will experience noise, traffic, and odor impacts during the project.  The anticipated traffic impacts are described below, and we will try to minimize noise and odor impacts as best we can.  

Project Location Map

Traffic Impacts:

West Portal

  • Lane closures on E. Orchard Road from S. Ogden Court to S. Humboldt Court will be required with approved traffic plans by City of Centennial and City of Greenwood Village
  • E. Orchard Road will be temporarily re-striped to maintain 2-way traffic. Both directions of travel will be shifted to the north.
  • S. Cherrywood Circle will be closed at E. Orchard Road and traffic will be detoured to S. Clarkson Street.
  • A traffic plan is below for reference.

East Portal

Significant impacts to traffic are not expected at the east portal since work will occur on Southgate’s property and adjacent sewer easements. Traffic impacts at the east portal are expected to be minor, infrequent, and relating to equipment and material deliveries.

Emergencies (Sewer Spill or Back-up, or Safety Concern)

Call Southgate at (303) 779-0261 (select option 8 after hours to speak with a Field Operator)