Flood Warning Targets Foothills

San Bernardino County authorities on Monday said they expected to advise 113,000 residents and property owners in a 32-mile-long area that mudslides and flash floods “will likely occur with little or no warning with each rainfall” over the next few years.

The warnings were mailed to owners of properties north of Highland Avenue and Interstate 210, and to homes near flood-prone portions of San Bernardino, Fontana and Rancho Cucamonga, county spokesman David Wert said.

“I have never seen the county go to these lengths to advise people of a possible hazard before,” Wert said. “But then, we’ve never faced a flood risk of this magnitude before.

“It’s not uncommon to have a fire followed by a flood in San Bernardino County, but it’s usually restricted to a couple of canyons,” he added. “This is the first time in anyone’s memory that the entire watershed from one end of the county to the other has burned all at once.”

The letters advise residents to make sure their property is protected with sandbags; to have emergency food, medical supplies and communications on hand; and to heed storm and flood warnings.

Crews from various agencies have been going door-to-door in high-risk areas since November, and have made tons of sand and thousands of sandbags -- plus instructions on how to use them -- available free of charge at local fire stations.

In recent weeks, however, hillside residents and canyon dwellers have charged that county authorities could have done more to warn them of mudslides, such as those that took the lives of 16 people in Devore and Waterman Canyon on Christmas Day.

But the advisory letters point out that “no one can accurately predict the precise location and intensity of approaching rain.

“Storm runoff occurs immediately and flash floods can result without adequate time to respond or retreat,” the letters state. “Flash floods and mud flows can occur anywhere, but are more likely to occur in existing watercourses, canyons, foothill and low lying areas. Areas adjacent to the burn areas are especially susceptible.”