Sonoma County regional water officials plan for ‘managing what we have now’

Anyone seeking assurance, some small sign of hope, that talk of a third-year of drought was premature, didn’t find it.

Nor did they hear dire warnings of reservoirs and wells running dry, nor of inevitable hardship.

Perhaps because we’ve more often been in drought than out of it over the past decade, speakers at a drought town hall Thursday night were mostly matter-of-fact as they doled out facts about the state of the region after 2 1/2 exceedingly dry months — months when heavy rain was needed to offset storage deficits lingering from last year and the year before.

The town hall was hosted by Sonoma Water, the county agency that provides water to more than 600,000 consumers in Sonoma and northern Marin counties through contracting municipalities and water districts.

The discussion touched on impacts to rural water users, fisheries, urban customers and beyond, as well as planning and exploration of new techniques focused on leveraging high wintertime flows to improve drought resilience in the future.

Little was said outright about the sacrifices that will be needed in the months ahead, though it was implicit in the messaging.

Yes, disciplined conservation will be necessary.

Additional water use restrictions may be coming.

Russian River curtailments will be back, though not until at least April 2.

Farmers will continue to struggle.

Vulnerable populations of young salmon and steelhead trout are at risk because of low stream flows.

And the last decent rain we got in December is likely to be the end of it, though the region’s public reservoirs are only about 60% full.

“If you look at our county, depending on where you are situated, we are either in extreme drought, which is the dark red there, or severe drought, which is the darker orange, and that’s likely to get worse as we enter into the drier months of the year,” Sonoma Water general manager Grant Davis said, referring to the most recent U.S. Drought Monitor map.

Davis was among six panelists who spoke during the nearly two-hour meeting, which was attended by almost 600 people on Zoom and Facebook. Hundreds more have since watched recordings.

“We are essentially nearing the end of our wet season,” said Jeanine Jones, interstate resources manager for the California Department of Water Resources. “On average, California gets 75% of its annual precipitation from November through March, and half of it in December, January and February. So we have already passed our three wettest months.”

With no significant rain on the horizon for March, and April rains, if they should come, are destined to be far lighter than winter storms, “the bottom line is that what we have now is pretty close to what we will end up with,” Jones said. “So we need to think about managing what we have now for the rest of this water year.”

Most of the region, if not all, has had under an inch of rain since January. But for the water season overall, Oct. 1 to Sept. 30, the Russian River watershed has had on average 78% of normal, Jones said.

Much of that arrived during a record-setting atmospheric river in October, followed by several December winter storms.

Water managers say the Russian River’s “flashy” system — which whipsaws swiftly between dry and high during heavy rain — has some period of high flows every single winter, even in the driest years, at least as far back as 1908. They’re referring to runoff in the watershed and in tributaries that reach the river in high volumes and drain to the ocean unless captured beforehand. It is not water released from one of the region’s public reservoirs or which otherwise would be retained by one.

The key to the future, they say, is putting that surplus to good use.

“I think this is the direction we’re more and more going to be going, which is utilizing winter water,” Sonoma Water chief engineer Jay Jasperse said in an interview Friday, “because right now, when we have the water is 180 degrees from when we actually need the water.”

In the weeks and months after October’s big rain, for instance, the water agency skimmed “a few million gallons a day” of extra water from the river as it flowed past the agency’s diversion facilities near Wohler Bridge and Westside Road in Forestville, Jasperse said.

That water was then made available to contractors, most of which augment what they buy from Sonoma Water with other local sources, such as wells or reservoirs.

The extra winter water meant cities could “rest” the groundwater wells on which they leaned heavily last summer so the wells would be in better shape if and when cities turn to them again this summer, Jasperse and Sonoma Water principal engineer Don Seymour said Friday.

It also allowed the Marin Municipal Water District to refill reservoirs, “which going into the fall were severely depleted,” Jasperse said.

North Marin Water District backfilled Lake Stafford near Novato, Seymour said.

Sonoma Water has diverted extra winter water in the past, but never as strategically as this year, “because we haven’t needed to, I guess,” Jasperse said. “But now we’re really called on to use that kind of coordinated, strategic management.”

Future projects include studies and potential implementation of Flood-MAR, or managed aquifer recharge, through flooding of agricultural and working lands during wet periods to recharge groundwater aquifers.

There may also be other ways of storing excess winter water in small surface reservoirs, as well, Jasperse said.

“If we start to match up the rest of our system on the diversion side and the storage side to what Mother Nature is delivering in the Russian River system, that’s going to build a lot of resilience,” he said.

The county also is working to replicate new wintertime operational guidelines for Lake Sonoma that already allow extra water to be held back in Lake Mendocino when there are no heavy rains anticipated. The technique, pioneered by Sonoma Water and the U.S. Army Corps in partnership with the Center for Western Weather and Water Extremes at Scripps Institution of Oceanography, is called Forecast Informed Reservoir Operations and allowed the operator of Lake Mendocino to preserve 18% of the reservoir’s storage in the 2019-20 drought year, Jasperse said at the town hall.

In the short-term, the water agency received $6.9 million in state grant funding to upgrade two wells in the Santa Rosa Plain to ensure the water they produce is properly chlorinated and the equipment up to standards for use during emergencies.

The project, aimed at restoring an older, inactive well, originally drilled in 1977, is similar to one completed last fall at a site off Todd Road, southwest of Santa Rosa. It can now deliver up to 1.6 million gallons a day when in operation.

That’s Phase One, and the first of the two, west of Santa Rosa off rural Sebastopol Road, should be activated within the year, Davis and Jasperse said.

Phase Two involves equipping the wells so they can be used to recharge the groundwater basin when wintertime water is plentiful.

“This is my fourth multiyear drought,” Jasperse said, “and when I look back on the first one, the tools we had and the viable information we had was much more limited than we have to deal with this drought. And I know future managers will have more. That’s the goal, is continued improvement and moving the needle.”

A recording of the virtual town hall, with slide presentation, can be viewed on the County of Sonoma’s Facebook page. It also is posted on the Sonoma Water website at sonomawater.org/drought.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.