Mayor Eric Garcetti’s call to strengthen Los Angeles’ water system — one pillar of his ambitious plan to ready the city for a major earthquake — would cost as much as $15 billion and require decades of work, Department of Water and Power engineers estimate.

The previously undisclosed cost projection, contained in an internal DWP report reviewed by the Los Angeles Times, could mean sharply higher water bills for those who live and work in L.A. It also underscores the financial uncertainty surrounding a key element of the mayor’s first-term agenda.

Since Garcetti announced his sweeping earthquake-safety proposal in December, public attention and political debate have centered on requirements to strengthen unsafe buildings. But the plan’s most far-reaching impact could be its scheme to fortify the city’s sprawling network of water pipes and aqueducts.

Water infrastructure is “the single biggest vulnerability we’re facing in Southern California,” according to U.S. Geological Survey seismologist Lucy Jones, who oversaw development of Garcetti’s earthquake proposals. Safeguarding the system is essential, the mayor argues, to prevent businesses from shutting down and a “mass evacuation” by people who lack water to drink, shower or flush toilets in the aftermath of a severe earthquake on the southern San Andreas fault.


The financial demands of earthquake-proofing L.A.'s water system create a political conundrum for the mayor. He has stressed his commitment to carry out his entire plan — both the retrofitting of buildings and improvements to water and telecommunications infrastructure.

“I’m not going to just settle for a little part of this getting done,” Garcetti said during a presentation to the L.A. Chamber of Commerce last month.

At the same time, the mayor so far has refused to commit to even modest rate hikes to fund basic repairs to hundreds of miles of decaying water pipes.

Garcetti’s earthquake plan seeks to reconcile these positions by calling for a statewide bond to pay for earthquake-proofing water infrastructure in L.A. and elsewhere. But the mayor has no firm timeline for passing such a measure, and even his plan’s supporters say the bond idea could be a tough sell amid competing initiatives in Sacramento.


Absent outside help, the billions would have to be paid through increased water rates for L.A. residents and businesses. The DWP analysis did not calculate what those increases might be under different retrofitting scenarios. But one potential measure of the project’s possible impact can be seen in San Francisco, where a $4.8-billion retrofitting effort is expected to triple the average water bill.

Rate hikes of similar magnitude could be politically untenable in L.A., where residents and business owners have often been resistant to utility bills rising and critical of the DWP’s customer service.

“It wouldn’t fly,” said Jack Humphreville, who tracks DWP issues as a member of the Greater Wilshire Neighborhood Council. “I think you’d have a riot.”

DWP engineers submitted their report to the mayor’s office in September, months before Garcetti released his own earthquake preparedness plan. The mayor’s proposal incorporated the engineers’ research, but omitted their conclusion that a full overhaul of the water system “requires a $12- to $15-billion investment over 20 years or more.” If accurate, that estimate would make the program one of the costliest infrastructure projects in California history.


Responding for the mayor’s office, Jones said a state bond measure is a “multi-year proposition” and that the infrastructure improvements Garcetti envisions don’t have to be achieved overnight.

“The mayor’s got many years to be able to see it through,” she said. “We don’t know when the earthquake’s going to come.”

Eileen Decker, deputy mayor for public safety, said the mayor’s office did not include DWP’s price tag for water improvements in its earthquake plan because the figure was speculative and could overlap with expenses already budgeted for ongoing pipe replacement.

“We asked DWP to come up with a guesstimate,” she said, “but it hasn’t been flushed out.” She said the mayor’s staff “want to understand with greater detail where the number came from.”


She said the utility has also been asked to devise less expensive plans to earthquake-proof only the most vulnerable parts of the water system.

DWP earthquake-engineering expert Craig Davis acknowledged there could be some overlap between earthquake-specific work and repairs DWP is already planning. But he said he doubted the full retrofitting plan could be carried out for less than $12 billion, even after accounting for such overlap. The work would include developing more local water supplies, fortifying the Los Angeles Aqueduct where it runs across the San Andreas fault and replacing large portions of L.A.'s more than 7,000 miles of pipes.

A stripped-down plan involving “the minimum you would do” to improve infrastructure in the areas of the city most at risk would cost $4 billion, Davis said. By comparison, the department currently plans to spend only $1.3 billion over the next 10 years on new pipes, independent of Garcetti’s earthquake plan.

Prone to leaks and increasingly past its prime, L.A.'s century-old water system has nevertheless proved durable in an earthquake-prone region. It survived heavy shaking in the 1971 Sylmar quake and again in the 1994 Northridge quake with minimal long-term damage or disruption of the water supply for firefighters — an admirable track record in a city that imports nine-tenths of its water across an active fault line.


But since the 1990s, the city has lost access to a number of local water supplies, making the system more vulnerable and the prevention of pipe ruptures more important. DWP’s solution involves installing a Japanese-manufactured pipe with flexible joints that in an earthquake can compress or bend without breaking, like a chain.

Such pipes, already in use at several pilot sites in L.A., are two to three times as expensive as those the city routinely uses.

Davis noted that the utility — a self-funded agency unable to draw on city tax dollars — faces restrictions in how it can raise money for earthquake improvements. If the agency sells bonds, it would likely have to increase customers’ rates to repay investors, he said.

“We had a difficult time getting the mayor’s office to actually understand that at first, and they do now,” Davis said. “And that’s why they said they want to go for a state bond.”


But the search for cash in the state capital hasn’t gotten far.

City officials are working with state legislators to craft tax incentives for property owners who retrofit their buildings to comply with the mayor’s proposed safety standards. But little progress has been made on water-system funding.

“We haven’t discussed the idea of a bond at all,” said Councilman Mitchell Englander, who has traveled to Sacramento with other L.A. officials to promote the mayor’s plan. “It’s just a tougher nut to crack.”

Mark Ghilarducci, director of Gov. Jerry Brown’s Office of Emergency Services, praised Garcetti’s willingness to tackle earthquake safety. But he said L.A. officials should look for money closer to home before turning to Sacramento.


“I’d never say that a [state] bond is out of the question,” Ghilarducci said. “But it really should not be the first place for a community to go.”

peter.jamison@latimes.com