California’s water year is nearly over. Here’s where our reservoirs stand amid drought
With California about to experience perhaps the hottest and driest start to September in its modern history, 16 of the state’s 17 major reservoirs entered the month below their historic average levels — several of them well below average, in another daunting reminder of California’s extraordinary ongoing drought and water concerns.
The state’s two largest reservoirs, Shasta Lake and Lake Oroville, were measured at a respective 58% and 64% of their averages for the end of August, according to data from the California Department of Water Resources.
Folsom Lake, which had been above its average as recently as July 14, finished August at 82%. The U.S. Bureau of Reclamation earlier this summer had to accelerate releases at the lake — a key export source of water for Southern California — to make up for dwindling levels at Shasta Lake.
Only New Bullards Bar, a reservoir in Yuba County within Tahoe National Forest, came in above average through the end of August. The reservoir was 70% of its total capacity, which is 104% of normal for this time of year, according to state water data.
Six smaller reservoirs — Casitas, Castaic, Pine Flat, New Melones, McClure and Trinity — are below half of average. Trinity Lake was at just 25% of its total capacity, which is 38% of its Sept. 1 average.
Extreme drought or worse across Valley
The U.S. Drought Monitor in a weekly update Thursday recorded 98% of California in at least “severe” drought status, 40% of the state in “extreme” drought and 17% in “exceptional” drought, which is the scale’s highest classification.
Extreme drought conditions blanket the entire Central Valley; within it, the San Joaquin Valley comprises essentially the entire pocket of exceptional drought.
The latest drought numbers actually mark an improvement from the beginning of September 2021, when 47% of the state was considered to be in exceptional drought, but remain a letdown after deluges last October and December.
California’s water year runs from October to September. After a flourishing start that included an October “bomb cyclone” storm in Northern California and the Bay Area that brought Sacramento a single-day rain record, as well as powerful storms in the Sierra Nevada mountains that also broke records last December, the entire state is poised to finish the year with precipitation totals significantly below average.
Much of California, including Sacramento and the central Sierra Nevada mountains, took in record-low precipitation this January through March before recovering some in April.
Most of the Sacramento region ranged between about 80% to 90% of average rainfall from Oct. 1 to Sept. 1 according to data from the National Oceanic and Atmospheric Administration.
The numbers have been more dire elsewhere in the Central Valley. The greater Redding area received about 60% of its historic average for precipitation over the past 11 months, and the Fresno area came closer to 50%.
And because the state’s biggest storms came so early in the water year, the year-to-date numbers remain front-loaded. Snowpack melted to zero in the southern Sierra mountains by early May and in the central Sierra by early June, thanks in part to heat waves during spring.
That means soils and vegetation had plenty of time to dry out, becoming susceptible as wildfire fuel.
This story was originally published September 1, 2022 at 10:19 AM.
