SANTA CLARA COUNTY (KRON) — Looking back at rainfall totals over the weekend, KRON4 found that one South Bay reservoir was the beneficiary of an unexpected rainfall–and windfall.
But KRON4’s Rob Fladeboe reports the extra rain was too much too soon and must be released.
The amount of water at Uvas reservoir, in the hills northwest of Gilroy, entirely dependent on runoff from rainfall, rose almost 10 percent last weekend, from 30 percent to just under 40 percent of capacity. The water level rose because more than 11 inches of rain fell upstream in the Uvas Canyon in the Santa Cruz Mountains.
But because it arrived so early, the water technically cannot be diverted and must be released.
Instead, the water will go to downstream interests, whose water rights predate those of the Santa Clara Valley Water District and to satisfy environmental needs which demand that a certain flow be maintained in the creeks and streams fed by the reservoir.
Uvas Canyon can see upwards of 100 inches of rain in the wettest of years. In stark contrast, Chesbro reservoir, not 10 miles away and fed by a different watershed, gained little from the recent storms.
Frequently among the first to be filled by the rain, releasing water from Uvas reservoir is also done at times in the name of flood protection but far more likely to occur much later in the rainy season.