Lake Mead – Intake No. 3 Connector Tunnel

OWNER: Southern Nevada Water Authority

ENGINEER: MWH

SOUTHLAND HOLDINGS TEAM: Renda Pacific LLC

PROJECT HIGHLIGHTS:

This project, located near the Hoover Dam, consisted of a deep water intake, a pumping station, and a large diameter water supply tunnel between the intake shaft and pumping station. The project serves as a lake tap structure and conveys raw water to the Alfred Merritt Smith Water Treatment Facility. The intake shaft is 26 ft. diameter by 450 ft. deep excavated by drill and blast methods and supported with rock bolts/mesh and a concrete liner.

In addition, the two connector tunnels consisted of a 380 LF of 20 ft. x 20.5 ft. horseshoe tunnel and 2,150 LF of 14 ft. x 16.5 ft. horseshoe tunnel. Both of these tunnels were supported by rock bolts and shotcrete lined. A temporary bulkhead was installed in the IPS-3 connector tunnel. Pre-excavation grouting was constantly required throughout the tunnel to hold off 300 gpm of groundwater. Over 5 million pounds of cement was required to grout the entire project.