Oct. 1 marked the beginning of the new water year, and the state’s water reserves appear healthy after a year that saw above-average precipitation.
Water years run from October through September. At the end of the most recent water year, statewide reservoir storage was 128 percent of its average, which equates to approximately 29.7 million acre-feet of water.
Lake Oroville is 100 percent of its average for the date compared to just 61 percent of its average at this time last year. New Bullards Bar Reservoir and Shasta Lake are both significantly higher than they were last year, too, currently at 116 percent and 125 percent of their averages, respectively.
Willie Whittlesey, assistant general manager of the Yuba Water Agency, said the above-average precipitation came in the form of moderate intensity storms with relatively low snow levels. More than 30 atmospheric rivers made landfall in Northern California last water year, according to the Department of Water Resources.
“We had near-record snowpack, which provided an extended spring runoff period and ample water supply,” Whittlesey said. “…We are at our target storage level and have experienced a little bit of abnormal early season runoff from the recent thunderstorms, which is a great way to start off the season.”
Eric Kurth, a meteorologist with the National Weather Service, said that the state received about 140-150 percent of its average amount of precipitation last water year. Locally, Beale Air Force Base received 153 percent of its average – typically, the base would receive about 20.50 inches in a water year, but last year it received 31.46 inches.
Another monitoring point at Englebright Reservoir showed the area received 140 percent of its average, or 47.22 inches of rain. Grass Valley received 132 percent of its normal precipitation levels, he said.
California is known for its variable weather patterns. As residents have come to learn, flood or drought can happen on any given year. Whittlesey said something in the middle is what the agency is hoping for.
“We always hope to avoid the extreme weather conditions of drought and flood. An average water year with a strong snowpack would be ideal,” he said.
The Climate Prediction Center’s current outlook through February projects below normal precipitation in Northern California and much of California. Seasonal forecasting can be difficult though, Kurth said, as there are many different factors at play that could impact what happens.
The state, especially Northern California, is largely dependent on storm systems like atmospheric rivers to provide water for the entire system. If a few strong systems miss the area, Kurth said, it can make a huge difference.
“What we could have today could be gone tomorrow,” said Karla Nemeth, director of DWR, in a press release. “Conserve. Recycle. Recharge. People and the environment depend on it.”