Grand Jury report raises alarms about water security following an earthquake

First the electrical grid, now the water supply is being identified as one of the necessities of modern life that may be at risk in case of disaster.

The 2018-2019 Sonoma County Grand Jury report, issued in July, addresses several areas of concern that county residents and governments should be aware of, and prepare for. One of them is found in the 'water report,' a 17-page document that poses the question, 'Will there be water after an earthquake?'

Though it's a generalized concern, for engineers in the water industry – including those at the Valley of the Moon Water District – it's a hair-on-fire worry, especially in light of the unexpected recent closure of a water treatment plant at the Sonoma Development Center by the state's Department of General Services.

'I'm pretty upset by it,' said Alan Gardner, general manager of the Valley of the Moon Water District since April. 'If they were thinking of closing the (SDC) plant, they could have told us, 'You guys better have a backup plan.'' But Gardner says a backup plan to the water that the SDC plan could supply would mean developing two or three wells, a project that could take up to three years and a million dollars each.

'If they could have given us three years notice, or even two, we would have been fine.' Instead, Gardner worries every day that in case of an accident, earthquake or other disaster, his agency won't be able to deliver the water his 17,000 customers need for much longer than a day.

Danger of earthquake

It's taken as a given that in case of a major earthquake, the county water supply 'will probably be disrupted,' the grand jury reports. Water throughout most of the county, including to Sonoma Valley, is delivered by Sonoma Water, aka the Sonoma County Water Agency. They manage the distribution of Russian River water through a network of pumps, aqueducts and storage reservoirs to 600,000 customers, both residential and business.

While the agency projects that a minor earthquake of 5 or less would not impair water supply or services, a major earthquake of magnitude 7 or higher very likely will, producing from three days to two weeks of disrupted service depending on what facilities are damaged. As the City of Sonoma is at the end of the aqueduct servicing the Sonoma Valley, it is especially vulnerable to damage sustained upstream.

'It will put the Valley at additional risk if the aqueduct from the Russian River fails, as it did during the 2017 firestorm or if it were to sever in an earthquake,' said Chris Petlock, secretary of the VOMWD board of directors. He said that could leave the entire Valley with 'little to no drinking and sanitation water while the aqueduct is down,' including the City of Sonoma.

Preparing for such an eventuality, Petlock said, 'goes a little further than residents just having a few days of water on hand.' In case of such a major earthquake, pumps would keep the several reservoirs in the Valley topped off with groundwater to maintain water pressure, but that's a short-term solution, perhaps as short as two or three days.

Sonoma Water's assurances that it can return to full function in a three-day period is regarded skeptically by the jury. 'Three days is an optimistic estimate,' reads the Grand Jury report. 'Other factors and experience point to more extended water outages' of up to two to three weeks, the report continues.

It says that Sonoma Water's own estimate of a three day return to service is flawed for several reasons – lack of training and documentation, and a sparse inventory of emergency supplies among them.

Facility shut down

Meanwhile, local alarm bells were set ringing by the recent shutdown of the Sonoma Developmental Center's water treatment plant, which further reduces the Valley's emergency backup water supply – and endangers both Fern and Suttonfield reservoirs on or near the SDC campus, manmade lakes that rely on diversions from local streams.

While the facility was open, the water treatment plant serviced SDC residents and employees, which at one time were well over 2,000 people. 'SDC is bracketed by (Valley of the Moons's) service territory, and VOM has a service main through it connecting VOM's two territories,' wrote Valley of the Moon Water District (VOMWD) manager Gardner to Sonoma County Superior Court Judge Gary Nadler, who oversaw the grand jury.

'SDC has developed and maintained two lakes, three dams and a surface water treatment plant supplying all the water used at SDC for all residents, staff and other purposes,' Gardner continued. The two have had an 'inter-tie' since 2002, a direct, metered connection between the two systems of water, and Valley of the Moon has provided technical assistance to the SDC water plant staff.

'The existence of this independent backup source has now been relied upon for the health and safety of VOM's residents for 17 years,' said Gardner.

But in late May of this year – less than a month before General Services took over the now-shuttered SDC campus, including its water treatment plant – it was announced that the SDC might close its water plant, supposedly because it was difficult to hire a new senior operator.

Gardner's response was blunt: 'Closing the plant would substantially degrade VOM's readiness. It would terminate that independent source of treated water and limit the ability of VOM, in the near term, to even serve drinking water after one day if the aqueduct is out of service.' He noted that he has three people on the VOMWD staff who are qualified to take over as senior operator of the SDC plant, but the state never began a recruitment process.

Gardner said that General Services 'does not appear to want to spend the money or continue the liability of maintaining the plant, even though VOM's residents will be without water after one day if the aqueduct fails.'

However, Sonoma County 1st District Supervisor Susan Gorin said taking over operations of the old SDC plant isn't so simple.

'The water treatment plant has been out of compliance for a number of years, and Sonoma Water would not agree to take over operation of the plant for the state because of the many deficiencies,' said Gorin, in her capacity as a Sonoma Water director.

Sonoma Water's chief engineer Jay Jaspers called it 'antiquated' and said that, once the three-year transition period is over, 'I would imagine that whatever happens at that site would probably be a major renovation.'

City water

In the City of Sonoma, engineers are more confident of their ability to respond to the two-week emergency that the grand jury projects. Public Works Director Colleen Ferguson, who's also the city engineer, said, 'During that time, City operators could run the City's wells and meet anticipated demand in a state of emergency which would require conservation. The City is developing a response plan for immediate implementation in the event of loss of Sonoma Water aqueduct supply.' That response plan is expected to be completed by the end of the year.

Ferguson said that prior to the power shutdown, City staff ensured that generator fuel tanks were filled and used PG&E power to top off the City's water tanks.

But despite the confidence in some quarters, the grand jury report, in its evaluation of the various jurisdictions that Sonoma Water serves, concluded that 'None of these water systems has sufficient underground water supply capacity to meet its regular local water demand without the Russian River supply.' And in case of an earthquake that ruptures the aqueduct, 'water supply interruptions in some areas could be significantly longer than three days, and local reserves could be depleted by then.'

To deal with the possibility if not eventuality of a major earthquake, the Grand Jury cites a recommendation from the Federal Emergency Management Agency: 'FEMA is recommending that you have enough water for each member of your family to meet their needs for two weeks.'

The general rule of thumb is to store one gallon of water per person per day, according to the Centers for Disease Control and Prevention. For a family of four, that's 56 gallons for two weeks – or 467.6 pounds.

More, if you want a bath.

Contact Christian at

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