SAN JOSE, Calif. — After the driest January, February and March in Northern California’s recorded history back to 1849, rains this past week finally brought some relief — and real benefits — across the Bay Area and other parts of the state.
But the wet weather was kind of like receiving wrinkle cream for your birthday, experts said Friday. Better than nothing. But not enough to celebrate.
Simply put, 2 to 3 inches of rain fell in the Santa Cruz Mountains, North Bay Hills and Big Sur over the past week. The Sierra Nevada received 1 to 3 feet of snow over the past week, depending on the location, the most since December.
That desperately needed moisture will delay fire season, experts say. It clears the air, boosts flows in streams for fish and wildlife, charges up the spring wildflower season and will reduce water consumption somewhat because people turn off lawn sprinklers when it is raining.
But California was heading into the third summer in a row of severe drought before the rain. And a few April showers — likely the last hydrologic hurrah until October — can’t make up for three years of major water shortages, experts noted.
“Any little bit is nice. But this is not going to make a significant difference in the drought,” said Jeanine Jones, interstate resources manager for the state Department of Water Resources.
The issue is basic math.
San Francisco historically has averaged 1.6 inches of rain for the month of April. This month, through Friday morning, it had received 1.08 inches. And no more significant storms are forecast.
In other words, the April showers this year haven’t even brought most parts of the Bay Area up to average for a typical April. It just seems like a lot because it’s been so unusually dry since New Year’s Day.
“Compared to January, February and March, it has been a really rainy month,” said meteorologist Jan Null of Golden Gate Weather Services in Half Moon Bay. “Everyone has been craving rain.”
“We’ve had so little,” he added. “It’s much more noticeable than it would be normally. It has risen up in people’s consciousness. But it’s too little, too late.”
A closer look shows just how badly the Bay Area, and nearly all of California, remains in a serious rainfall deficit.
In the 34 months since July 1, 2019, San Francisco, used as a proxy for the Bay Area because it has the longest-running set of weather records of any city, has received 39.16 inches of rain. The historical average for that time period is 67.77 inches.
In other words, San Francisco has received just 58% of normal rainfall for nearly the past three years and has a deficit of 28.61 inches, even when the latest rain is included. Put in context, that deficit is more than an entire average year of rainfall for San Francisco, which is 22.89 inches.
The region is basically missing more than an entire year of rainfall over the past three years. And that can’t be made up in a week.
The recent rain also didn’t do much to fill reservoirs.
On April 1, all 10 reservoirs operated by the Santa Clara Valley Water District, a government agency in San Jose that provides water to 2 million people, were just 25% full. On Friday, they were still 25% full. That low number is in part because of meager rainfall but also because of the fact that the district’s largest reservoir, Anderson, near Morgan Hill, is drained for federally mandated earthquake repairs.
It was a similar story at East Bay Municipal Utility District, where all seven of the district’s reservoirs were 71% full on April 1 and on Friday were still 71% full. Small amounts of water have flowed in, but not much, district officials say.
“It takes a lot to move the needle,” said Andrea Pook, an East Bay MUD spokeswoman.
Los Vaqueros Reservoir, a linchpin of Contra Costa County’s water supply, was 59% full on April 1 and Friday remained at 59% full.
Even the state’s largest reservoirs have similarly shrugged amid the latest storms.
Shasta Lake, near Redding, the biggest reservoir in California, was 38% full April 1. And Friday it was 39% full. Oroville in Butte County did a little better, going from 47% full April 1 to 51% full Friday.
After the three extremely dry months, some of the rain soaked into dry soils. Some ran into reservoirs. But cities and farms continue to consume it. And some was released as required under federal and state laws for fish and wildlife to keep rivers downstream from drying up.
The Sierra snowpack, source of nearly one-third of California’s water supply, has seen a modest boost in April. After receiving more than 2 feet of snow in the past week, Palisades Tahoe, formerly known as Squaw Valley, extended its closing date from May 1 to May 15. But it will only be open on Fridays, Saturdays and Sundays for those extra two weeks, and most other Tahoe resorts have either already closed for the season or are closing by Monday.
On April 1, the northern Sierra snowpack was 26% of its historical average for that date. On Friday it had jumped to 37%. But the storms didn’t bring much snow to the Southern Sierra. So averaged out, the statewide Sierra snowpack on Friday was just 35% of normal.
The biggest benefit from the April rain, apart from wildflowers and better waterfalls at Yosemite?
“This will delay fire season by a few weeks,” said Craig Clements, director of the Fire Weather Laboratory at San Jose State University. “A month ago it was looking pretty grim.”
Barring any extreme heat waves, fire risk will be lower in May and June than it otherwise would have been, Clements said. But the rain and snow now won’t lower the risk during the most dangerous time of years for wildfires, September and October, Clements said.
Currently 95% of California remains in a severe drought, according to the U.S. Drought Monitor, a weekly report put out by the federal government and University of Nebraska. With a long, dry summer ahead, wildfire risk will be high, and residents will be increasingly asked to conserve water in case the drought drags into 2023.
“We really can’t expect the wet season to continue much longer,” Jones said. “We are basically at the end of it.”
