A series of extremely wet winter storms aimed at the North Coast is expected to put some roadways under water and raise local rivers to the brink of flooding as the weekend nears.
If all goes well, there could be enough time between waves of intense rainfall to prevent significant flooding, though emergency crews will be monitoring conditions closely in the event they need to respond, officials said.
“We’re just kind of in watch and wait mode,” Petaluma Fire Battalion Chief Mike Medeiros said Wednesday, echoing sentiments from authorities around the region.
Still, officials were clearly bracing for what lay ahead. In Lake County, for instance, the gates of the dam at Cache Creek were opened to relieve Clear Lake of some its water before the storm. In southern Lake County, officials were watching still-bare hillsides scorched by the Valley fire and other blazes, hoping erosion control measures would hold.
The Army Corps of Engineers also was releasing water from Lake Sonoma.
“We’re already making preparations here at the road yard to go in 24-hour operations if we need to,” Sonoma County Road Operations Manager Rob Silva said.
The National Weather Service said five days of rain lay ahead, with the heaviest rainfall arriving early Thursday and lasting until Friday night, dumping nearly 4 inches of rain on Santa Rosa and up to 7 in the coastal hills.
Continued rain through Monday was projected to drop another 2 inches in Santa Rosa and up to 5 inches on wettest areas in the hills. Windy conditions were expected, as well.
A flash flood warning has been issued for the Bay Area and the North Bay urging residents to be prepared for urban and small stream flooding through Sunday, given soil saturation levels from previous rains.
The Russian River was expected to crest just shy of flood stage in Guerneville on Saturday morning and should come close in Hopland, as well.
Silva, the Sonoma County roads chief, said sand for sandbags would be distributed Thursday to the Forestville and Monte Rio fire departments, as well as the old rodeo grounds on Armstrong Woods Road.
With rivers already high, just a small increase from the forecast could be enough to push some local waterways over their banks, said National Weather Service meteorologist Brad Charboneau.
“It’s definitely something to keep an eye on,” he said. “There’s always a little uncertainty in a forecast, but especially this type: If it stalls, then all of a sudden we end up with a little more rain than we’re expecting. And when we’re that close to flood stage already...”
The Navarro River in southern Mendocino County is projected to crest near the coast at 35 feet —13 feet over flood stage — likely closing Highway 128 near the intersection of Highway 1, which is also likely to flood at the Garcia River crossing on the Mendocino Coast, Caltrans spokesman Phil Frisbie said.
The Russian River, though not expected to flood, could get just high enough to close Highway 175 in Hopland, as well, he said.
Frisbie said Caltrans crews would be patrolling hot spots and closing any roads that had too much surface water for them to be traveled safely.