Torrential rains over the holiday weekend have left Humboldt County reeling, with several roads flood-damaged and impassable, and more rain is on the way.

“The storm came and hit us hard on Saturday,” said Thomas Mattson, the county public works director. He said his agency had been working round the clock to repair washed-out roads that had left some residents stranded.

In Redwood Valley, off Highway 299, flooding from the Mad River damaged both main access roads Saturday, cutting off residents from outside aid. The 113-mile river flows northwest through the county and the rural unincorporated community. Repairs to the roads were not expected to be completed until late Wednesday.

Eureka’s daily newspaper the Times-Standard reported that at least 30 households were struggling with flooded homes and power outages amid dwindling supplies and no way to access help.

During an eight-hour stretch Saturday, 2 to 5 inches of rain fell throughout Humboldt County, according to Tyler Jewel, a meteorologist with the National Weather Service’s Eureka office. The community of Whitethorn recorded nearly 8 inches of rainfall.

“It’s a very small watershed,” Jewel said. “This last storm just happened to dump a ton of rain there. … It’s really rare for that river to flood.”

Mattson said the county’s public works crews had reopened 15 flooded roads since Saturday but were still dealing with half a dozen that sustained serious damage.

Ryan Derby, emergency services manager with the Humboldt County Sheriff’s Office, said there had been “county-wide flooding” over the last several days. The agency declared a local state of emergency Tuesday to expedite emergency repairs and state and federal aid.

Derby said flooding from the Mad River affected Tyee City and other agricultural land in that area, along with parts of Mad River Road, or what’s locally known as the “Arcata Bottom.”

Small creeks and streams overflowed into the Blue Lake area, not far from the Blue Lake Rancheria tribal land, about a 10-minute drive from Arcata.

Other flooding stretched from Hoopa in the north down to Shelter Cove in the southwestern tip of the county along the coast.

Some of the affected areas are “sparsely populated,” Derby said, and no evacuation orders were issued, though some residents fled during the rainstorms on Saturday. No deaths or injuries have been reported.

County officials are still assessing how much damage was caused by the rain so far, Derby added, and they will meet Thursday to discuss the situation and this weekend’s expected rain. Derby said the county is referring affected residents to the Red Cross at (800) 733-2767.

Derby said the storms caused damage to county roads and culverts, and with more rain set to arrive Friday, he worries that additional flooding could interfere with recovery efforts.

“It’s not anticipated to be as severe,” he said of the rain forecast. “But there could be compounding factors with the incoming storm that pose additional issues.”

Forecasts indicate 2 to 3 inches of rainfall are expected throughout Humboldt County — though the King mountain range in the southwest could receive up to 5 inches — between Friday and Monday, with the first wave of rainfall arriving Friday morning through Saturday morning and the second from Saturday night until Monday afternoon.

Higher rainfall amounts of 4 to 6 inches were expected throughout Mendocino County south of Humboldt, with both the Russian and Navarro rivers having the potential to flood, Jewel said.