Last week’s storm was helpful in aiding the region’s thirst-quenched soils, but drought conditions remain in spite of the ample rainfall.
During a mid-January Turlock Irrigation District Board of Directors meeting, hydrologist Olivia Cramer warned that the Tuolumne River Watershed had accumulated far less precipitation than the historical average, putting the current water year on track to become one of the driest on record.
Following an atmospheric river event which brought heavy wind and rain to Turlock and much of the state on Tuesday night, however, things are looking up. On Tuesday, Cramer shared with the Journal that the significant amount of rainfall moved the watershed from around 8% of average for the month of January up to 109%.
“We received more than the monthly average for rainfall in January just during the last week and a half of it,” Cramer said.
Although the total rainfall for January was boosted during the large storm, the water year to date, which begins in September, is currently just 64% percent of average. For comparison, last water year sat at about 51% of average. The storm did nearly double the total rainfall for the entire water year, though, which was just 35% of average prior to last week.
“It didn’t get us all the way to where we wanted to be, but it definitely helps to replenish the soil moisture up there, which overall makes the system more efficient for any kind of future storms which could run off into Don Pedro,” Cramer said.
The snowpack also improved thanks to the storm, which luckily brought freezing temperatures and provided more powder in the Sierra Nevada. Snow is crucial to TID irrigation, Cramer said, as the Tuolumne River Watershed is a snow-dominant watershed; for example, while the snowpack grew exponentially last week, Don Pedro gained just a foot in overall elevation. The snowpack jumped from 43% of average before the storm and is now at 72% of average.
“That’s where we get a majority of our water supply rather than direct precipitation,” Cramer said. “When we go into spring that starts to run off and helps fill Don Pedro and allows us to provide to our customers for irrigation.”
During the last Board of Directors meeting on Jan. 12, Cramer told Directors that wet conditions during the rest of the water year would provide an average amount of rainfall compared to the historical average, while normal conditions would lead to a dry year. Dry conditions would have seen irrigation numbers cut, most likely, but January ended up pulling its weight when it came to precipitation.
The outlook is good looking ahead, as well, as February is typically the second-wettest month of the water year. If the wet conditions remain now, TID is looking at a water year that would be 114% of normal. Average conditions would produce a year 67% of normal, while dry conditions would see a water year that is 44% of normal.
Current forecasts for the next 16 days are extremely volatile with ranging predictions, Cramer said.
“Unfortunately, a lot of it is a waiting game. Post February we usually can start locking in those numbers a little bit better,” she said. “...Through every drought you learn a lot of things...Hindsight is 2020; you never know if the next year is going to be a historically-dry year. We usually try to plan for a dry year, but those conditions are within a probable range and sometimes a year can set a new record.”
While the current water year isn’t as dire of a situation as it seemed just a couple of weeks ago, California still remains in a drought.
According to the U.S. Drought Monitor, 100% of the state is still experiencing at least some level of drought, with levels ranging from abnormally dry to moderate, severe, extreme and exceptional drought. Nearly 39.46% of California is in either an extreme or exceptional state of drought — up from 34% in mid-January. According to the monitor, all of Stanislaus County is currently classified as experiencing severe drought.
“Overall, this event was definitely helpful for us and put us into a better position for this year, but we’re not completely out of the woods,” Cramer said. “It really depends on how conditions move forward and hopefully it stays wet.”
To view the U.S. Drought Monitor, visit https://droughtmonitor.unl.edu. Cramer will give a full water report during the next TID Board of Directors meeting. For more information on the date and times of meetings and how to view them, visit www.tid.org