Extreme flood risk as Northern California storms swell rivers

San Jose officials were bracing for the possibility of the worst flooding to hit the San Francisco Bay Area’s most populous city since the 2017 surprise flood of Coyote Creek, which cuts through the heart of San Jose and forced more 14,000 residents to leave their homes and flooded hundreds of homes.

San José is one of several places where flood risks have increased significantly. like a series of new storms barrel in Northern California this week, river floods.

The National Weather Service warned of moderate flooding that could reach San Jose beginning Monday morning. At the same time, the Guadalupe River on the Almadén Freeway was expected to exceed minor flood levels of 9.5 feet and, by the afternoon, reach a moderate flood level of 11.5 feet.

At 9.5 feet, the river water is expected to “surpass upstream of the Alma Avenue Bridge toward Elks Lodge,” located just south of the Caltrain commuter rail system’s Tamien station.

At 11.5 feet, floodwaters would spill north along Lelong Street, flooding the overpass at Highway 87 and Alma Avenue, and risk inundating properties in San Jose’s Northern Cross neighborhood.

San Jose officials planned Sunday to send workers to communicate evacuation orders to homeless residents along the Guadalupe River and Coyote and Penitencia creeks. The Santa Clara Valley Water District was monitoring the following locations for potential flood areas: Ross Creek at Cherry Avenue; Upper Penance Creek at Mabury and King Roads; Berryessa Road; and the Penitencia Alta neighborhood; Guadalupe River at West Alma Avenue; and Canoas Creek in the Nightingale neighborhood and on Santa Teresa Boulevard.

“It is likely that there is a threat to life during these storms,” ​​the weather service said in a bulletin. “Soils remain saturated, which means a high risk of flooding and shallow mudslides. Expect rapid increases in creeks and creeks, as well as increases in major rivers. Periods of high winds gusting to 40 to 60 mph (potentially higher in the mountains) could cause downed trees or power outages.”

Officials warned they were watching many rivers for potential flooding, including the Russian River in Sonoma County in Guerneville, which is forecast to reach moderate flood stage, and in Geyserville; Mark West Creek near the Mirabel Heights community; Santa Rosa Lagoon on Stony Point Road west of Rohnert Park. Other rivers of concern included Alameda Creek in northeast Fremont and in the foothills east of the city; Pacheco Creek southeast of Gilroy; San Lorenzo River north of Santa Cruz; the Pajaro River and Corralitos Creek around Watsonville in Santa Cruz County; and the Salinas River south of Salinas; the Carmel River along the Carmel Valley; the Big Sur River; and the Arroyo Seco south of Soledad.

In Mendocino County, the Navarro and Garcia rivers remain a flood threat and are already flooding highways. The Eel River near Arcata in Humboldt County is being closely monitored.

In the Central Valley, flooding is expected on the Cosumnes, Mokelumne and Tuolumne rivers. Bear Creek bisects Merced and the creek could reach record flood levels, reaching 27.1 feet Tuesday morning; the record is 24.65 feet in 2006.

Meteorologists warned of a “relentless parade of cyclones” Leaving the Pacific for Californiawhat was expected intensify flood risk in some parts of the state this week. A flood watch remains in effect for the Sacramento and San Joaquin Valleys and nearby foothills until 4 p.m. Wednesday.

The first of five approaching atmospheric rivers — a stream of storms that will continue through about January 19 — arrived this weekend. Heavy rain and mountain snow began late Friday in Northern California and spread to central California Saturday, with some parts of the state expecting more than a foot of snow through early Sunday.