The Uvas Reservoir in Morgan Hill is the fullest it has been in three years, pointing to a positive trend in the county’s water situation after a long dry period.
As of Jan. 4, the reservoir was 96% full, and was a few inches away from pouring over its emergency spillway, according to Herman Garcia of Gilroy-based Coastal Habitat Education and Environmental Restoration, who frequently monitors the reservoir.
Authorities said there was no flood risk associated with Uvas Reservoir surpassing its capacity. Valley Water spokesperson Matt Keller said the district is working with local agencies to monitor any hot spots, such as the bridge into the Thousand Trails RV Park and the Miller Avenue crossing in Gilroy, for any impacts.
The reservoir last spilled over in February 2019.
It’s a far cry from earlier in 2021, when Valley Water, which operates 10 reservoirs in Santa Clara County, reported that Uvas Reservoir was at 15.9% of capacity, while the Chesbro Reservoir slightly further north was at 14.3% and the Coyote Reservoir east of Gilroy was at 18.5%.
According to Valley Water data, as of Jan. 4, those reservoirs were reported at 96%, 57% and 40% of capacity, respectively.
Countywide, the average capacity for Valley Water’s reservoirs was just under 28%, compared to 12.5% in August.
Joel Casagrande, a fish biologist with the National Oceanic and Atmospheric Administration, said it’s “only a matter of time” before the Uvas Reservoir spills over capacity, adding that much more water is flowing into the reservoir than what is being released downstream.
Last week, Valley Water went from releasing 5 to 6 cubic feet of water per second to 100 cfs for three consecutive days, according to Casagrande.
The increased flow from the reservoir into Uvas Creek helps prevent the habitat from becoming static and proves to be a boon for fish, Casagrande said, adding that steelhead were recently spotted just below the dam after a long absence.
“The last two years have been really, really lean,” he said. “I don’t think there was any juvenile production in Uvas Creek last year. These storms are a sign of good things to come this winter.”
Water from the Uvas Reservoir, constructed in 1957, is used to recharge supplies in underground aquifers.
The soaking rains that closed out 2021 proved beneficial for Santa Clara County and its drought situation.
According to the U.S. Drought Monitor, Santa Clara County on Dec. 27 moved into the less-intense “Severe Drought” classification. A week earlier, it was considered to be in “Extreme Drought,” just one level below the driest category of “Exceptional.”
“We have seen a great start to our wet season with the local rains and snow in the Sierra Nevada giving our water supply a much-needed boost,” said John L. Varela, director of Valley Water’s District 1.
Despite the positive trend, Varela said local residents still need to conserve water.
Valley Water supplies took a hit when the federal government ordered Anderson Reservoir in Morgan Hill to be drained while it undergoes a seismic retrofit. Work on the 10-year project began in June and means Anderson is nearly empty.
As of Jan. 4, the reservoir was a little more than 5% full.
“We’re hopeful more storms are coming, but there are no guarantees,” Varela said. “We need well-above-average rain and snow in the coming months to make up for the historically dry seasons we’ve endured.”
Valley Water offers water-saving tips and rebates at watersavings.org.
To prepare for possible flooding, free, filled sandbags are available at the El Toro Fire Station, 18300 Old Monterey Road in Morgan Hill, and unfilled sandbags at the Corporation Yard, 613 Old Gilroy St. in Gilroy.