Construction Sequencing and Phase Planning for Large-Diameter Urban Waterlines

The Las Vegas Valley Water District (LVVWD) is 5 years into an 8-year, multi-phase program to replace approximately 10-mi of waterline along the Las Vegas "Strip." Since the project's inception, the phases have been re-sequenced and adjusted in length several times to account for strict maintenance of traffic requirements, simultaneous nearby infrastructure projects, stakeholder concerns, and frequent high-profile special events (including concerts; marathons; and professional sporting events, such as the NHL All-Star Game, the Super Bowl, and the Formula 1 Las Vegas Grand Prix). As a result of this rephasing, the planned points of connection for each phase have not always aligned with existing mainline valves, presenting challenges for construction, and for the abandonment of existing waterlines. It was essential that the design be strategically planned to avoid shutdowns that would impact major resort casinos within the project vicinity. Additionally, the design was tailored to eliminate long dead-end mains, which, without proper planning, would remain in service after project completion. This presentation highlights the strategic use of linestops with attention being given to critical design considerations, including site selection, thrust restraint, and reinforcement design. Construction photos demonstrating the installation process will be presented.