With just one month left in the precipitation year and little rainfall to show for it, Turlock Irrigation District and its customers are currently experiencing the fourth-driest year on record.
According to TID hydrologist Olivia Cramer, the Tuolumne River Watershed has received just 18.23 inches of precipitation since Sept. 1, or just about half of the historical average. The TID precipitation year, which is different from the water year, runs from Sept. 1 through Aug. 31 and will come to an end next month. The water year runs from Oct. 1 through Sept. 30.
This year’s 18.23 inches of rainfall come as the region experiences a second-straight year of drought conditions and puts 2020-2021 in the record books as TID’s fourth-driest precipitation year on record. The three driest years on record in order are 1977 (10.90 inches), 1976 (17.46 inches) and 2015 (17.50 inches).
According to Cramer, the data for dry years goes back 90 years. Recent rainfall brought just .01 inches of rainfall last week, and July is a month that historically sees an average of just .16 inches. Cramer explained that although storms are expected to hit California this weekend, they won’t impact the dry conditions locally.
“Overall most of it’s occurring on those Eastern Sierras...Most of this is thunderstorm activity so a lot of those scattered storms, and often those aren’t usually captured by our precipitation station network,” Cramer said.
The lack of water comes as the area also experiences higher-than-normal temperatures, with another heat wave expected next week. The normal temperature for this time of year is about 94 degrees, Cramer said, but the forecasts show that next week will reach up to 104 degrees.
While Don Pedro still has sufficient storage for local farmers to utilize, the State Water Resources Control Board on Friday announced an order which could cut off thousands of water rights holders from the Sacramento-San Joaquin Delta watershed. The emergency curtailment was alluded to in June when the Board sent notices of water unavailability to all Delta water rights holders, and the draft emergency regulation is set to be considered during the Board’s Aug. 3 meeting.
“Due to severe drought in the West, the water supply in many parts of California, including the Delta watershed, is not enough to meet demands,” said Erik Ekdahl, deputy director of the Division of Water Rights, following the June warning. “We do not come to this decision easily. We are asking people to reduce their water use, and we recognize this can create hardships. However, it’s imperative that we manage the water we still have carefully as we prepare for months, perhaps even years, of drought conditions.”
California has experienced an unprecedented loss of runoff this spring as water was either absorbed by parched soils or evaporated amid unusually warm temperatures before reaching streams and reservoirs. High temperatures also prompted water users to use water earlier and in greater volumes than in previous critically dry years.
These developments resulted in the unexpected loss of nearly 800,000 acre-feet of water, enough to supply more than one million households for a year and nearly the entire capacity of Folsom Reservoir. In response, on May 10, Governor Gavin Newsom issued a drought proclamation that now covers 41 of 58 counties, including Stanislaus County, and encompasses 30% of the state’s population.
Newsom has also asked California residents to cut back water use by 15% as over a third of the state experiences the highest level of drought.