Lower Stone Canyon Bypass Line No. 2, Los Angeles, California Lessons Learned from Reservoir Bottom and Tunnel Pipeline Design and Construction

摘要

New EPA and State of California drinking water regulations mandate the filtration and disinfection of potable water supplies subject to surface water runoff. In response to these regulations, the City of Los Angeles Department of Water and Power (DWP) embarked on the $70 million Stone Canyon Water Quality Improvement Project, modifying facilities originally constructed in the 1920s and subsequently changed in the 1950s. Because of restricted access to the project site, sensitive nearby residential communities, and the scenic environs, design of a new 8,000-ft long bypass pipeline and appurtenant facilities was based on trenchless construction methods, and includes two tunnels and a reservoir bottom pipeline. The new Bypass Line No. 2 interfaces with the existing Bypass Line No. 1 and includes a new diversion structure, several large valves and metering vaults, a microfiltration plant and pump station, and a chlorination facility.