Last year’s record low rainfall a reminder that one storm doesn’t end the drought

News Release

Tri-Valley’s lack of rain from October 2020 through September 2021 marks all-time low

Last week, on the heels of what closed out the driest year on record for the Tri-Valley, the region was graced with a desperately needed atmospheric river storm that drenched much of California with historic rainfall. While this storm brought significant precipitation in a month that isn’t typically very wet, this isn’t the time to break those water saving habits and lose sight of the existing drought.

To put things into perspective, in tracking the “water year” which runs October 1 to September 30, last year the Tri-Valley got only 5.67 inches of rainfall for the entire water year, which is a mere 39% of the average rainfall. Last year surpassed the previous record for the lowest annual rainfall at 6.02 inches in 1977. In last week’s storm, the area received somewhere between 3.5 and 4.5 inches, quickly approaching last year’s total rainfall in just one week.

While the recent slew of storms has given existing water supplies a boost and provided an excellent start to the new water year, California’s weather is predictably unpredictable, and the Tri-Valley still remains in a Drought Emergency and Stage 2 Water Shortage Emergency.

As sunny skies return this week, Zone 7 Water Agency is encouraging residents not to forget that conservation is still necessary. The community’s help is still needed to reach the required 15% reduction in water use.  Water restrictions remain in place and customers of California Water Service, City of Livermore, City of Pleasanton and Dublin San Ramon Services District should check Zone 7’s drought page at for the latest drought information and city-specific water use restrictions.

One of the most impactful ways to save water is to reduce outdoor irrigation, which makes up 60% of household use. Hopefully, residents turned off irrigation during the storms and with such a heavy soaking, it should be several days before irrigation systems need to be turned back on.

The best bet is to wait to resume watering until the top two inches of soil are dry.  The “screwdriver test” is an easy way to find out when your lawn or garden needs water again. Take a screwdriver and stick it into a patch of soil. If it goes in all the way, there is enough water in the soil. If not, then it is time to resume watering.  Those that want to automate the process should check out Zone 7’s Weather-Based Irrigation Controller rebate.

For those thinking of ditching water-thirsty lawns, with the ground nicely soaked and the fall/winter season the best time for getting plants in the ground, now is a perfect time to start the process of converting existing lawn to water-wise or native landscaping. Zone 7 also offers a rebate and many other resources for those interested in starting the process.

Those without landscaping can conserve by installing water efficient appliances. Zone 7 now offers a $200 rebate towards the purchase of a High Efficiency washing machine.

For more info on rebate programs and water-wise resources visit