WaterBay Tunnel
A 5.5-mile immersed-tube rock tunnel carrying drinking water across the San Francisco Bay.

A deep rock pressure tunnel bypassing an ageing aqueduct, including a 1,100-foot drop shaft.
Feasibility through detailed design for a deep pressure tunnel and vertical drop shaft.
Over 900 feet of cover demanded careful characterisation of jointed rock and a lining concept capable of managing long-term groundwater pressure.
