Santa Cruz Water Department Completes Graham Hill Road Pipeline Work

New Newell Creek pipeline moves city water line out of Henry Cowell

By Mary Andersen

Water is now flowing through 3.7 miles of new pipe beneath Graham Hill Road. The Santa Cruz Water Department finished moving a stretch of the Newell Creek Pipeline out of Henry Cowell Redwoods State Park nearly three months ahead of schedule. Commuters will still see crews doing cleanup along Graham Hill Road, with work expected to wrap up by Thanksgiving.

For some San Lorenzo Valley residents, the project has raised concerns about the movement of San Lorenzo Valley water to Santa Cruz. Here’s what the record shows about the pipeline’s purpose.

What the pipeline does

The Newell Creek Pipeline carries untreated water from the city-owned Loch Lomond Reservoir to the Graham Hill Water Treatment Plant at 715 Graham Hill Road, Santa Cruz. It supplies roughly 10% of the city’s annual water. The city built the reservoir and the original pipeline around 1960.

In a 2023 federal funding request, the city described Loch Lomond as its only surface-water storage reservoir. When drought or storm runoff makes its other surface sources unusable, the city sends reservoir water to the treatment plant through this pipeline.

Why the pipeline moved

The old pipe ran under Pipeline Road in Henry Cowell through an easement with California State Parks. Its age, combined with hillsides that shift when heavy rain saturates the soil, led to increasingly frequent breaks. There were two breaks this past summer.

“Locating the Newell Creek Pipeline underneath Graham Hill Road eliminates vulnerabilities that have been a major challenge in the previous location,” Water Director Heidi Luckenbach said in a city statement.

Luckenbach told the Santa Cruz Sentinel that Graham Hill Road is wide, properly sloped and has stormwater drainage on both sides. “It should really be restarting the clock on ability to withstand the next 50 years,” she said.

Not a new supply

The new pipe is 24 inches in diameter. The old line varied from 18 to 27 inches. The city describes the project as a reliability fix for an existing line, not a source of new water.

The amount of water the city may take from Newell Creek is set by the state, not by the size of a pipe. The city’s state license allows it to store up to 5,600 acre-feet a year from Newell Creek, and it must release a minimum flow of 1 cubic foot per second below the dam. Relocating the pipeline does not change those terms. The new 24-inch pipe is close in size to the old line, and city officials have not indicated the project is meant to increase how much water moves through it.

The city puts the project’s cost at $29 million. Luckenbach told the Sentinel the total from design to completion was $31 million. Funding came from city water ratepayers, the state’s Drinking Water State Revolving Fund and $3 million from the U.S. Environmental Protection Agency.

City of Santa Cruz responds to concerns

In response to concerns from SLV residents, Luckenbach said, “The portion of the Newell Creek Pipeline that was replaced has no bearing on the frequency with which the City would pump water from the San Lorenzo River to Loch Lomond Reservoir under existing water rights.” And that it would have no impact on the ability of SLV Water District to utilize their allotment of water from Loch Lomond Reservoir.

“We appreciate the support and patience of San Lorenzo Valley residents as the City constructed this important project. This new infrastructure increases water supply reliability, important as we experience more intense and varied weather,” she said.

What’s next

The city water department has more infrastructure work underway. Next up it will present proposed treatment plant improvements to the Santa Cruz City Council. Proposed water rate increases to pay for upcoming projects go to a final public hearing before the council on Nov. 17.

Photos: City of Santa Cruz