The past decade was extreme weather-wise, according to a climate summary from the National Weather Service – Sacramento.
The report stated that the 2010s saw both drought and record wet weather. Interior Northern California experienced severe to exceptional drought during the 2012-2016 period with a state declaration being issued from 2013-2017 due to several years of below normal precipitation. In 2017, drought indicators had improved because of exceptional rains.
Michelle Mead, warning coordination meteorologist with the National Weather Service, said California is a state that often sees a lot of variation in its climate.
“California is one of the states that doesn’t like to play by the rules,” Mead said. “...The further west you get (in the country), the variation starts to increase … In the last 10 years, we’ve seen some pretty big extremes.”
She said while the winter season is typically when California gets most of its rain, there’s also sometimes a three- to six-week period when the rain stops and there is a dry pattern, but one storm has the potential to turn things around.
“California’s mantra should be conservation always, because water is a big commodity,” Mead said. “But we can turn around in just one storm.”
John James, water operations project manager for Yuba Water Agency, said the agency has to be adaptive to changes in weather forecasts when managing the area’s water.
Over time, they’ve seen runoff events from 400,000 acre-feet of water and up to more than 4 million acre-feet, said Curt Aikens, general manager of the agency.
The agency has to manage for things like flood-risk reduction and making sure there’s a reliable water supply for their customers.
Aikens said they can go from managing for flood protection one year, like in 2017-18 when there was record precipitation, to managing for a dry period, like this year where there’s been less precipitation than average so far. When there is a dry period the agency may have to think about not only this year but carryover for the possibility of a multi-year drought.
“California’s climate has always varied,” James said. “There are studies that show, in terms of percentage, that it’s the most varied region (in the U.S.) in terms of year-to-year precipitation.”
However, James said, looking ahead, there is the possibility of there being more and more extremes with climate change and resilience – the same amount of rainfall is expected but it might take place in a shorter period of time or the droughts might last a little longer.
The agency is working on a few projects to help reduce the region’s flood risk, enhance dam safety and potentially improve water supply, such as a Forecast-Informed Reservoir Operations, completing a secondary spillway at New Bullards Bar Dam and working alongside the U.S. Army Corps of Engineers, and other agencies, to update the water control manual for the dam and reservoir.
“What we’re doing now is we’re taking actions now for the future conditions so we can maintain flood protection and water supply benefits for the people of Yuba County,” Aikens said.
Franz Niederholzer, a farm adviser at the University of California Cooperative Extension, said the extremes in precipitation levels can be challenging for farmers.
“It’s kind of like cash flow in a business, it’s nice to have a steady situation so you can know what to expect,” Niederholzer said. “...Irregular weather can produce irregular income and that affects your business.”
He said when there’s a late wet season, it can affect when growers can get into their fields or when there’s too much rain and water, it could lead to more disease in the crops.
But growers are resilient and can take preventative steps and prepare for some of the challenges, Niederholzer said.
He said tree crop growers can plant on a slope so the water runs off or plant on mounds to help keep the roots and crown out of the saturated ground.
They can also use fungicides to protect the crop leaves and fruit from disease organisms.
With some crops, however, when the ground is too wet there isn’t much that can be done because growers can’t get into the field to do what they need to – like plant.
“You can do whatever you can do but there’s some things Mother Nature does that growers can’t manage,” Niederholzer said. “You can’t fix it, you just have to hope for the next year to be better.”
However, when there’s an extended drought period, it could mean the reservoirs get lower and the growers have to do more irrigation but the amount of water that’s available may be reduced.