Destructive Mariposa storm likely killed 2, officials say. These factors didn't help

Mariposa County Sheriff Doug Binnewies on Tuesday told the Board of Supervisors the March 22 storm caused significant destruction countywide.

“This weather affected a larger population, a greater geographical area, in five hours than the Detwiler Fire impacted us in five days,” Binnewies said, mentioning the wildfire last July that destroyed dozens of homes while burning more than 80,000 acres.

Two people from Mariposa County, 72-year-old Catheys Valley resident Carol Brown, and 67-year-old Don Pedro resident John Honesto, were reported missing in the storm, according to the sheriff’s office.

“Unfortunately, due to the force of this storm, we do presume both deceased,” Binneweis said, noting that they are still considered missing, but rescue efforts were scaled back.

Caltrans on Monday identified several factors that caused the major flooding incidents in Mariposa and Tuolumne counties.

In Bagby, where the Detwiler fire burned, mudslides brought debris down the hillsides over Highway 49, clogging drainage pipes and flooding the roadway.

“The road was not designed to withstand that kind of erosive action,” Caltrans spokesman Warren Alford said.

The massive Detwiler Fire burned much of the vegetation that would have normally helped soak up water and hold the soil together, Alford said.

That made it easier for heavy rains to cause mudslides on steep slopes, he said.

Several sections of Highway 49 were either damaged or severely compromised due to erosion and soil saturation, according to Caltrans.

Much of the human impact happened in the Lake Don Pedro area, Binnewies and other county officials said Tuesday.

Two water main breaks shut off water access to Lake Don Pedro residents, leading rescue agencies and American Red Cross to supply nine pallets of water, the equivalent of about 650 bottles, to the area, officials said.

Lake Don Pedro Elementary school was closed for the week due to flooding damage. The county is still working with Mariposa County Unified School District on food distribution for students who normally receive free and reduced lunches.

Officials said it could have been worse.

“We may have dodged a tremendous bullet because of the foresight and experience that our sheriff and his command staff and team bring to this county,” Mariposa County Public Works Director Mike Healy said.

Infrastructure created and maintained during the Detwiler Fire also helped with communication between emergency agencies and residents, officials said.

Binnewies thanked several agencies from surrounding counties for their help in responding to the floods and the missing individuals.

“All of your county agencies, supported by state and federal, are continuing to communicate and monitor our pocket communities,” Binnewies said. “Several homes have lost their driveways, private bridges, ingress-egress, and property damage. So several of our constituents are still facing difficulties.”

This story was originally published March 27, 2018 at 4:31 PM with the headline "Destructive Mariposa storm likely killed 2, officials say. These factors didn't help."