Conduit No. 16 Replacement-A River Tunneled under Your Feet

摘要

Denver Water's Conduit No. 16 was completed in 1937 to convey raw water from the Ralston Reservoir to the Moffat Water Treatment Plant. A recent study concluded that the two existing water conduits were approaching the end of their service life and Denver Water elected to replace Conduit No. 16 with a new larger pipeline and abandon the other conduit. Development along the alignment required design and construction of five tunnels to cross three roadways, a major shopping center, and two railroad tracks. Design and construction were complicated by contaminated groundwater, abundant cobbles and boulders, running sand, and deep bedrock. Three charrettes were held with tunneling contractors to discuss challenges and offer solutions to these issues. Design of the new conduit occurred between 2013 and 2018, and was complicated by an 18-month hiatus from late 2014. The hiatus was due to Denver Water studying and eventually deciding to build a new water treatment plant at the Ralston site. This resulted in Conduit No. 16 needing to be switched from a raw water line to a treated water line. In late 2017, work began on construction of the five tunnels and about one mile of open cut work.