Just because the rainy season has arrived doesn’t mean California’s water cops are off the job. With a fourth year of drought looming, some of the Bay Area’s biggest utilities continue to crack down on excessive outdoor watering. Most are responding to heavy sprinkler use or power-washing with a courtesy note, advising customers to stop what they’re doing with the threat of a fine.
So far, things are going well for Northern California heading into what is, on average, the busiest part of the rain and snow season. As of Monday morning, many locations around the region are reporting above-average rainfall totals since the water year began on Oct. 1. Downtown Sacramento has had close to 4 inches as of the most recent observation on Sunday.
Two atmospheric rivers (ARs) are forecast to make landfall along the US West Coast on 9 Dec and 12 Dec. The first AR is forecast to bring a short period of AR 1 conditions (based on the Ralph et al. 2019 AR Scale) to coastal Southern Oregon. The deterministic GFS and ECMWF have drastically different solutions for a developing area of low-pressure associated with the second AR, making it difficult to pinpoint the timing, IVT intensity, and landfall location.
Arizona is preparing to enter for the first time into a Tier 2A shortage for the lower Colorado River basin, with cuts beginning at the start of the new year. For the state, this means a reduction of 21% of Arizona’s Colorado river supply and about 9% of the state’s total water use, according to the Central Arizona Project. Cities that use the Colorado river will see a 3% reduction while tribal supplies will be reduced by 7%. And for the users of CAP water, there will no longer be excess water and agriculture pools from the Colorado River.
It’s beginning to look a lot like Christmas across the West, and for the parched mega-drought region, the December snow is a welcome gift. With back-to-back-to-back winter storms across the West, the snowpack is thriving. Parts of the Sierra and the Pacific Northwest are seeing above-average snowpack for this time of year. In Central California, the Sierra stands at 200% of normal for snowpack average to date.
Rainy weather. A series of storms that have brought rainfall to Santa Cruz County and heavy snowfall to the Sierra Nevada over the past few days should taper off by today, although the forecast over the next week shows unsettled weather and possibly more rain gathering on the horizon. The past three years of drought and the wildfires sparked in its wake, along with heightened worries over water supply, mean that the recent rains are a blessing.
The Sierra snowpack vital to supplying water for California’s residents, businesses, and farms is off to a strong start. Recent storms bringing rain to the Valley and other parts of the state are also dumping snow on the Sierra Nevada. According to the state Department of Water Resources, the northern Sierra snowpack is 155% of normal through Monday. Meanwhile, the central Sierra and southern Sierra snowpacks are 166% and 216% of normal, respectively.
At a sprawling sewage treatment plant in north San Jose, engineers are slowly perfecting the ideal temperature for a smelly mixture of bacteria and human waste as the stew churns inside four massive air-tight cauldrons. The plant, the largest wastewater treatment facility west of the Mississippi to produce water clean enough to be discharged into a sensitive ecosystem like San Francisco Bay, is experimenting with new heat-loving bacteria that excel at turning poop into compost and energy — harnessing the power of dangerous greenhouse gases
A line of storms that ushered in a chilly, soggy start to December should continue to move across Northern California early this week, offering more chances for rain in the Bay Area and a fresh coat of powder over the Sierra Nevada. One-third to a half-inch of rain could still fall over lower-lying portions of the Bay Area from Sunday through Tuesday morning — further boosting already healthy rainfall totals over the past several days.
As water in the Western U.S. becomes an increasingly rare commodity, the driest states are grasping at solutions for an even drier future — investing heavily in technologies to maximize the conservation, and creation, of the region’s most precious resource. With more than a thousand miles of Pacific Ocean coastline, California appears to have access to a wellspring that other arid states lack.
