Water pipeline replacement completed
220 feet of the pipeline runs beneath the San Lorenzo River
The City of Santa Cruz Water Department announced the replacement of a major water pipeline.
The City of Santa Cruz Water Department announced Tuesday the replacement of a major water pipeline, that diverts water from North Coast streams, has been completed. Less than a year after the $5 million project began, 520 feet of 1960s era steel water lines have been replaced by new ductile iron pipeline.
Majors, Laguna, and Liddell creeks feed into the newly-upgraded line. Water from those streams are then delivered to the the Graham Hill Water Treatment Plant, before arriving at customers’ taps.
“The pipeline that was replaced under the San Lorenzo River is like a main artery for the city’s water system,” Eileen Cross, spokesperson for the water department, wrote in an email. “Were it to fail, the city would be without a significant source of water — and in trouble supply-wise.”
For a length of 220 feet, the water pipeline runs beneath the San Lorenzo River. That made the project technically challenging.
“This project was a nail-biter for us,” said Water Director Rosemary Menard in a press release. “The pipeline beneath the San Lorenzo River is critical to the community’s water system and because of the location, failure was not an option.”
Kleinfelder Engineering and Vadnais Trenchless Services were
contracted by the City water department, and utilized micro-tunneling to complete the new section of pipeline. The technique involves using remotely operated machines to dig utility tunnels.
A 70-foot-deep pit was excavated to launch tunneling equipment and another 50-foot-deep trench was dug, where contractors received the remotelyoperated machines.
“The pits needed to operate the micro-tunneling equipment were 10
stories tall and 5 stories tall,” Menard said. “Managing groundwater seepage into the pits was an ongoing challenge that the team successfully met.”
The Cost Pump Station pipeline replacement is the first of several infrastructure upgrade projects the City water department has planned. At Loch Lomond, crews are currently working on replacing the Newel Creek Dam inlet and outlet.
That project is slated to cost more than $100 million, and will be ongoing for the next several years, according to water department staff.