Rain Shows Danger of Charred Hillsides : Calabasas: Conservationists educate tour-goers about soil erosion and the risk of floods and mudslides.

The tour was supposed to highlight the potential for flooding and mudslides in fire-stricken areas and, as luck would have it, rain made the message perfectly clear.

In fact, Saturday’s storm brought such a downpour and blinding mist at some points that it drove the official sightseers away from Saddle Peak Lookout, aborted a foray into Las Flores Canyon and cut short the bus tour sponsored by the Topanga-Las Virgenes Resource Conservation District.

Looking at the bright side, though, all that water made it easy for soil conservationists to explain their point--that the intense heat of a brush fire not only kills the plants holding dirt and rocks in place, but it alters the nature of the soil itself, making it more prone to erode once it gets top-heavy with water.

“If you lift your foot up and check underneath, that’s how far the water’s gone (into the soil) in the last 20 to 30 minutes,” said civil engineer Mark Cocke as he led the group in studying the inch-thick layer of mud caked onto their boots.

There, on a level lookout point off Stunt Road near Calabasas, the mud was relatively harmless, Cocke said. But on a slope, “this would be turning not into sticky mud but liquid mud coming down en masse.”

At every turn Saturday, there was similar evidence of the rain’s potential danger: small rocks strewn on roadways, rivulets collecting at roadsides and everywhere, it seemed, fire-charred hillsides devoid of vegetation.

The three-hour tour tracing the fire’s path through Calabasas, Topanga and Malibu on Nov. 2 was organized to promote preparation for fire and rain. About 45 participants, including public officials, homeowners and even a few contractors, piled into an old school bus for the wet ride through the Santa Monica Mountains.

“Planning and building are the secret here,” said Cocke, as he passed an enclave of sprawling Calabasas homes “poorly located” in his opinion beneath the shadow of boulders and 100-degree slopes.

“We human beings have chosen to live in the fire-prone environment. The environment will not change for now so we need to adapt to it,” Cocke said.

In addition to stricter zoning laws, he advocates the construction of smaller houses made of fireproof materials. The modest stone cottage in Cold Creek Canyon made more sense to him than the massive, faux chateaux down the road.

“A smaller home is also easier to defend” against fire, Cocke said, quickly adding: “Oh, boy, those architects are going to be after my hide!”

Just as new construction needs to be better planned, erosion-control efforts should be carefully thought through, the conservationists said.

As a prime example of a poor erosion-control plan, they stopped at Malibu Lagoon to show the group an enormous “burlap hill” across the Pacific Coast Highway, where the owner of a hilltop Mediterranean villa has swaddled the entire slope from his house to the highway in jute netting.

“The disturbance to the soil to lay it down probably defeated the purpose,” conservationist Rich Casale said.

“How can you advise against such a thing? Because this guy who’s doing it thinks he’s doing what’s proper and actually he’s doing it all wrong,” said Margot Feuer of Los Angeles, a longtime parks activist who until recently lived in the mountains.

Dennis Washburn, a Calabasas City Council member and president of the resource conservation district, said later that he and other conservation officials would try to reach the homeowner.

Casale also told the group that plastic sheeting can retain moisture on a hillside, and the heat generated by black plastic can even kill root systems. Improperly placed sandbags can drive water onto a neighbor’s property, he said.

“Every home site, every soil condition and drainage are a little different,” Casale said.