SAN FRANCISCO (CBS SF) -- Unlike a typical calendar year, the water year for California begins on Oct. 1 and the most recent season the drought-stricken region is leaving behind was one of the driest on record.
According to the National Weather Service, normal rainfall for Santa Rosa from Oct 1-Sept 30 is 36.28 inches. Over the most recent time span, the area received just 13.01 inches or 39 percent of normal.
For San Francisco, those totals were 23.65 inches for a normal year and just 9.04 inches fell during the 2020-2021 water year. It was the second-driest on record dating back over 170 years.
San Jose would be at 14.90 inches normally with just 5.32 inches falling over the last water year.
California also had its warmest ever statewide monthly average temperatures in October, June and July, according to the National Oceanic and Atmospheric Administration's National Centers for Environmental Information.
"Total precipitation across the region was abysmal for the second consecutive year," forecaster from the National Weather Service in Sacramento said in a Twitter post.
As of midnight Oct 1, the NWS downtown Sacramento climate station has gone 195 days without measurable rain. This beats the previous all-time record of 194 days set back in 1880.
The parched conditions has lead to state water officials issuing a dire warning as vital Northern California reservoirs like Lake Mendocino and the Lexington Reservoir dip to historic low levels.
It's possible the state's water agencies won't be able to get water from the reservoir system next year, a frightening possibility that could force mandatory restrictions for residents.
California's State Water Project — a complex system of dams, canals and reservoirs — helps provide drinking water to about 27 million people in the state. In December, state officials will announce how much water each district can expect to get next year.
Thursday, Department of Water Resources Director Karla Nemeth said the agency is preparing for what would be its first ever 0% allocation because of extraordinarily dry conditions.
"It's a done deal, we're sure that we will get a zero," said Demetri Polyzos, manager of resource planning for the Metropolitan Water District of Southern California that provides water for about 19 million people. "These are uncharted territories, what we are seeing."
California's giant system of reservoirs store up water during the rainy and snowy winter months. Most of the water comes from snow that melts in the Sierra Nevada mountains and fills rivers and streams in the spring.
Regulators then release the water during the dry summer months for drinking, farming and environmental purposes, including keeping streams cold enough for endangered species of salmon to spawn.
This year, unusually hot, dry conditions caused nearly 80% of that water to either evaporate or be absorbed into the parched soil — part of a larger drought that has emptied reservoirs and led to cuts for farmers across the western United States. It caught state officials by surprise as California now enters the rainy season with reservoirs at their lowest level ever.
"Nothing in our historic record suggested the possibility of essentially that snow disappearing into the soils and up into the atmosphere at the level that it did," California Natural Resources Secretary Wade Crowfoot said. "These climate changes are coming fast and furious."
The 2021 water year began with reservoirs at 93% capacity. But California won't have that cushion this year. The state's reservoirs are at 60% of their historic average, state officials said.
The State Water Project provides about 30% of the Metropolitan Water District's supplies, with the Colorado River supplying about 25%. The district also has some local supplies, including water it has in storage.
Last month, the agency declared a "water supply alert" and called for voluntary conservation. They're offering rebates for things like more efficient shower heads and appliances and replacing grass lawns.
Despite the severity of the drought, Gov. Gavin Newsom has not declared a statewide emergency. Instead, he has declared emergencies in 50 of the state's 58 counties, an approach his administration says is driven by lessons learned from the most recent drought when the state imposed restrictions statewide.
© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report
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