Work is underway to bore a tunnel under Highway 1 in Watsonville, which is part of the Pajaro Valley Water Management Agency’s College Lake Water Supply pipeline project.
The weeks-long tunnel job, just south of Riverside Drive, will not interrupt Highway 1 traffic flow, said Marcus Mendiola, water conservation and outreach specialist with PVWMA.
The job is the second of five trenchless crossings in the six miles of 30-inch water main that will transport treated water from a new College Lake facility on Holohan Road to more than 5,000 acres of farmland via the Coastal Distribution System already in place.
Overall project updates include:
• The contractor has installed approximately 38% of the six-mile pipeline (12,100 linear feet) as of the end of September.
• Construction should wrap up on College Road before Halloween.
• Pipeline is being installed off Riverside Drive from east of Highway 1 to just before town in farm fields.
• Pipeline is installed in farm fields west of Highway 1.
• The Water Treatment Plant with sediment basins and weir/pump station foundations are currently being built up with concrete being poured.
• Construction launched in spring with a completion goal projected to take 22 months.
• Each section of the 30-inch pipeline requires approximately two hours and 45 minutes to fuse together under many hundreds of pounds of pressure and temperature.
• All six miles of the pipeline have been delivered to the Pajaro Valley, in 40-foot-long sections.
• Tunneling under Highway 1 has begun. A crew has already bored a tunnel under Highway 129 (near Salsipuedes Bridge across Bridge Street from the Buddhist Temple).
• A 42-inch steel casing is inserted into the tunnel to keep the highway stable and protect the future pipeline. Once the casing is established, the water pipe is inserted into the casing and any empty space is grouted.