West Side Reservoir Near-Collapse | Replacement to Cost Millions of Dollars

The structure located in the Monterey Hills is currently compromised, sagging in several areas

SOURCE: Google Maps | The reservoir structure's sagging is indicated by pools of water seen in this satellite image

“A ticking time-bomb.”

That’s how South Pasadena City Council Member Evelyn Zneimer described the condition of the city’s 2-million-gallon West Side Reservoir during a city council meeting May 5. It could cost over $10 million to replace the reservoir, some of which may have to be funded through new water rate increases.

The 58-year-old circular tank and its associated pumping station, located at 820 Glen Place, supplies water to the Monterey Hills.

- Advertisement -

Zneimer said the once-flat concrete roof, supported by concrete posts, is sagging in so many places around its perimeter that it is now shaped like a sombrero.

The roof is slowly separating from the walls, allowing water to seep onto the surface where it pools and corrodes the roof’s reinforcing rebar. The rebar protrudes visibly through the concrete. There are cracks all around the tank’s thick concrete wall, from which at least three major pieces have fallen away.

“Particularly problematic is the reservoir does not meet current seismic standards,” added a staff report. Public Works Director Shahid Abbas said what make him “apprehensive” is that many of rebar segments are sheared off.

The Council unanimously supported a staff recommendation to solicit proposals for a detailed structural assessment “as soon as possible,” followed by a plan to consider whether the reservoir should be rehabilitated or replaced. It authorized $100,000 for the study from the city’s Water Enterprise Fund reserve.

Abbas agreed with Council Member Jon Primuth’s assessment that the roof’s “post tensioning cable” construction method is the “structural equivalent of a rubber band.” Primuth wanted to know if reservoir rehabilitation was even possible, and whether the study cost could be reduced if the Council were to simply direct staff to study only replacement.

Notably, in an October 2013 Water System Operations report, the city said it had already concluded that West Side Reservoir “needs to be replaced.”

Abbas said his personal opinion was that rehabilitation of the reservoir would not be cost-effective. But he did not directly answer the study cost question, saying he obtained information suggesting bids on the study would come in between $70,000 and $135,000, hence the $100,000 authorization figure. He said he believes that Walnut Creek-based Carollo Engineers, which has a half million-dollar professional services agreement to prepare the city’s Integrated Water and Wastewater Resources Management Plan, is likely to bid on the low side for the work as it is already “mobilized” and working for the city.

As part of its existing contract, Carollo prepared the visual facility inventory and operational assessment that led staff to recommend the West Side structural analysis.

A cost estimate to replace the reservoir and its affiliated pump station is already built into the city’s existing five-year water rate design, but that estimate is from 2017 and comes to $7.5 million. In response to a question from Council Member Michael Cacciotti, Abbas said the cost is now likely to be at least $10 million. He confirmed Cacciotti’s assertion that “the ratepayers are going to have to pay” the additional cost. Current water rates call for annual increases through January of 2022; it was unclear if the rate structure would have to be adjusted to accommodate the increased cost of refurbishing the reservoir or if the cost would be shifted to post-2022 rates.

As of June 2019, the staff report said, there was $6.4 million in unrestricted reserves in the Water Enterprise Fund. The city is hoping to secure additional funding through a state revolving fund, as it did at a favorable interest rate for the recently completed $10 million Graves reservoir reconstruction project.

Repair of the West Side reservoir roof has been contemplated by the city since at least 2009 when the project, then estimated at $130,000, appeared on the capital improvement program (CIP) list the city included in the official statement of the $43.4 million water revenue bond it issued that year. It told investors “the city expects to fund the CIP with proceeds of the 2009 bonds and with ongoing system revenues.” It indicated the money would be spent in fiscal 2009-10.

When the 2009 water bond was refinanced in 2017, West Side reservoir appeared again on the CIP, this time with an estimated cost of $7 million through 2025.

The financial impact section of the May 5 staff report did not address how much of any remaining bond funds are targeted for the West Side project.

With the refurbishment of the city’s four other reservoirs over the last 20 years, “we have replaced 80 percent or our reservoir system,” Cacciotti observed. “Now we have to look back at an almost 60-year-old reservoir which we’d hoped would last longer,” he said, noting Graves lasted nearly 100 years.



Ben Tansey is a journalist and author. He grew up in the South Bay and is a graduate of Evergreen State College. He worked in Washington State as a reporter in a rural timber community and for many years as an editor for a Western electric energy policy publication based in Seattle.