Debris flow danger seen in approaching Southern California storms

Riverside County emergency management officials went door-to-door Friday, Sept. 28, in the area where the Holy fire burned in Lake Elsinore, warning residents that dangerous debris flows could result from storms arriving in the next few days.

The edge of Hurricane Rosa, coming from the south, is expected to skirt that area before a second storm blows in from the northwest, the National Weather Service said. The two storms could meet up Tuesday, when up to 2 inches of rain could fall near Lake Elsinore and in the mountains, said Noel Isla, a weather service meteorologist.

The Holy fire burned 23,136 acres and 18 cabins or homes in Orange and Riverside counties in August.

Officials with the Riverside County Emergency Management Department will also fan out Saturday in the Lake Hemet area in the San Jacinto Mountains, where the Cranston fire burned 13,139 acres and 12 structures south of Idyllwild in July and August, spokeswoman Brooke Federico said.

“We want folks to understand the Holy fire and the Cranston fire left the soil scorched with little ability to absorb water, and these debris flows can be created with intense rain. We want residents to understand the danger,” Federico said.

Officials have held regular conference calls with the National Weather Service this week, Federico said.

Meanwhile, the National Weather Service put out a beach hazard statement Friday that will be in effect starting Sunday morning and lasting through Tuesday afternoon in Los Angeles, Orange and San Diego counties. Waves in Orange County will be in the 5-to-8-foot range, with occasional sets reaching up to 10 feet.

The swell will peak Monday and decrease through Monday night and Tuesday. There is also a danger from rip currents, which can pull swimmers out to sea.

Rosa was 1,000 miles south of San Diego on Friday. It is expected to make landfall over the northern Baja Peninsula and accelerate toward Arizona and the Four Corners region. Most of the rain will be east of Southern California with rain developing in the mountains and lower deserts as early as Sunday.

The storm from the northwest could combine with Rosa’s remnants and produce showers and thunderstorms as it moves inland Tuesday into Wednesday, the weather service said. The chance of rain in Southern California should disappear Wednesday night.

Flows of debris and mud followed the Cranston fire, and officials want residents to be braced for a repeat next week.

“Debris flows are deadly, fast-moving landslides. They move faster than somebody can run, faster than somebody can drive,” Federico said. “It’s essential to evacuate if you are ordered.”

Residents can visit the RivCoReady website at rivcoready.org to sign up for alerts by clicking on Alert Rivco to register. Residents of the Holy and Cranston burn areas may enter their addresses on interactive maps to determine the risk to their homes. Click on Be Storm Ready and scroll down to the maps.

Meanwhile, Caltrans contractors who are doing paving and guardrail replacement on Highway 18 between Lower Waterman Canyon and Highway 138 in the San Bernardino Mountains were preparing for the storms by working to protect drains and slopes from runoff, spokeswoman Terri Kasinga said.

Emergency officials recommended these safety steps:

• Know your local access roads and understand that some may be blocked by debris or water.

• Do not attempt to drive through a flooded road, especially with moving water.

• Have an emergency plan and disaster kit ready.

• Protect your home with sandbags, which are available at Cal Fire stations in Lake Elsinore and Corona.