LAN performed an internal condition assessment for 15,000 LF of 96-inch PCCP water transmission main to identify areas requiring repair or improvement. The transmission line is part of the City of Houston’s largest transmission line system from the East Water Purification Plant and transports an average of 105-MGD to downtown Houston and further west. Because of its criticality, the line was selected for assessment, but also places a major burden on the City while it is taken out of service for an extended period of time. LAN also performed hydraulic modeling, assisted with shut down planning, and designed upgrades to the existing cathodic protection system. To permit the shut down, LAN’s planning efforts included design and construction of 5,000 LF of small diameter distribution waterline and installation of two 96-inch temporary line stop valves.