By Vicky Boyd

Although the water year is off to a slow start, water managers and growers say it’s still early to become concerned and they remain optimistic that rain and snow will return this winter to fill reservoirs.

They also point to the state’s robust reservoir storage carryover as cause for a more positive outlook than the past few years. In fact, most of the state’s reservoirs currently have more than 100 percent of average storage for this time of year. The California water year runs from Oct. 1 through the following Sept. 30.

“We probably won’t think about water until February,” said Steve Knell, general manager of the Oakdale Irrigation District. “It’s just way too early. Really, a couple of big storms can change us around from where we are today.”


The irrigation season ended in late October for growers within the South San Joaquin Irrigation District (pictured here near Ripon), and Mother Nature has provided scant moisture since then. But water managers say they’re not overly concerned because the rainiest months are still to come. Photo by Vicky Boyd. 

The irrigation season ended in late October for growers within the South San Joaquin Irrigation District (pictured here near Ripon), and Mother Nature has provided scant moisture since then. But water managers say they’re not overly concerned because the rainiest months are still to come. Photo by Vicky Boyd.


The National Weather Service’s climate station in Stockton recorded 0.91 inches of precipitation from Oct. 1-Dec. 14, according to the Climate Station Precipitation Summary. That was 27 percent of normal for that date.


During the same period in 2016, the Stockton station recorded 4.66 inches, or 137 percent of normal. During a normal year, the station receives 14.06 inches of rain.

Knell pointed to January being historically rainy. And so far, he said, long-range forecasts have given no indication that the San Joaquin Valley is in for a prolonged dry period.

In addition, many of the state’s reservoirs are sitting at minimum flood levels, meaning any additional inflow from storms would prompt releases to maintain a safety buffer.

New Melones Reservoir, for example, stood at 1,985,330 acre-feet or 145 percent of average storage as of Dec. 14, 2017. That compares to only 560,734 acre-feet, or 33 percent of average, at the same time in 2016. An acre-foot, about 326,000 gallons, can meet one to two family of four’s water needs for a year.

New Melones, which serves OID and the South San Joaquin Irrigation District as well as the Bureau of Reclamation, has a capacity of about 2.4 million acre-feet.

Dave Simpson, a Lodi area winegrape grower who chairs the SJFB’s Water Committee, echoed Knell’s sentiments.

“The two-week forecast is dry, and it makes me a little nervous,” Simpson said in early December. “It needs to rain, and we need frost. But after all those years of drought, when you start the year with the local reservoirs actually having a lot of water in them and it’s forcing water districts to release water down the rivers, I’m still OK with that. They have to get them down to allow for what could happen to provide flood protection.”

In a perfect world, he said it would be nice to capture some of that water being released and use it for groundwater recharge. Simpson also pointed to the need for more reservoir storage.

“It’s unfortunate that we don’t have additional storage reservoirs where we could capture that water that we’re just releasing to the ocean right now and make better use of it later,” said Simpson, who also sits on the North San Joaquin Water Conservation District.

If the weather pattern remained dry through December and into January, then Simpson said he’d become “a little more nervous.”

In early December, the Bureau of Reclamation was still releasing pulse flows for Delta fisheries, something that Mary Hildebrand noticed in the south Delta.

“The levels are still pretty good – over 2,000 cubic feet per second through Vernalis,” said Hildebrand, who farms in the south Delta and is a San Joaquin Farm Bureau board member. She was referring to a flow gauge on the San Joaquin River near Vernalis that also provides data for Delta water quality determinations.

So far, she said Delta water quality has remained significantly below mandated salinity standards, except for one unexplained spike in the south Delta that came close but didn’t exceed them.

Not only will the total amount of precipitation this year affect Delta flows but storm timing also will play a role, Hildebrand said.

“If a whole year’s precipitation comes in three weeks, you can still end up with flood releases,” she said, citing 1997 as an example. “We had a very wet December, levee breaks in January and the rest of the year wasn’t particularly wet. When we get these big atmospheric river rain events and then it dries up, all bets are off. The whole (reservoir) system was built for snow melt, not atmospheric rivers.”

Despite the large reservoir carryover storage, the Department of Water Resources on Nov. 30 issued its initial 2018 allocation of just 15 percent for State Water Project contractors. 

That allocation will likely change, depending on rain and snowfall received this winter. 

“It’s hard to know what Mother Nature will have in store for us this year, but it’s safe to say California is in a better place than we were during the recent drought,” DWR director Grant Davis said in a news release.

The 2018 initial allocation is less than the 20 percent made for the 2017 water-use year but more than the 10 percent made for both the 2016 and 2015 water-use years.

The State Water Project, comprising 27 water contractors, serves about 30 percent agricultural users and about 70 percent urban and business users.

Officials with the Bureau of Reclamation, which operates the federal Central Valley Project, expect to announce initial allocations in late February in keeping with contractual agreements, said Todd Plain, bureau spokesman.

“Drought-related conditions forced us to delay the announcement (in 2017), but this year we anticipate staying with the more typical late February timeframe,” he said.

In addition to districts north of Sacramento and around Fresno, the CVP supplies a handful of water districts on San Joaquin County’s west side. It also provides a small amount of water to Stockton East Water District during normal and wet years.