Mountains will recover on their own terms

Nobody moved to La Cañada Flintridge to live with concrete barriers lining their streets as though the family had chosen to bivouac at the edge of a battleground.

But everybody who lives in La Cañada Flintridge knows or will likely come to know the glories and dangers of living at the edge of the wilderness.

The San Gabriel Mountains send torrents of mud downhill on a regular basis. They did so when Los Angeles was just a little pueblo, and they will continue to do so for centuries.

The long view is important when considering the current clash between some residents and city officials over the concrete barriers — or K-rails — on Haskell Street and Big Briar Way.

Residents want them out right now. The City Council voted unanimously this week to leave them in place, with the possible exception of one on Haskell that is considered a traffic hazard.

The K-rails were installed after the Station fire in an effort to redirect possible debris flows, which in past storms have made streets rivers of mud, carried cars into pools and destroyed homes by knocking them off their foundations and filling them with boulders and silt.

Geologists with the U.S. Department of Agriculture’s Natural Resource Conservation Service came to La Cañada last month to study whether the foliage on local slopes has recovered enough to stabilize the soil and warrant the removal of the barriers. They determined that it hasn’t, and that is unsurprising.

Reforestation efforts have mostly failed, despite the fact that a million seedlings were planted in the Angeles National Forest after the fire. In addition, a dry winter in 2011-12 meant both no mudslides and restrained recovery of soil-stabilizing plants.

The mountains are recovering on their own schedule.

Geologists will return next year to survey the scene again, and maybe then they will tell homeowners what they want to hear: that the debris basins and natural defenses against the mudflows appear to be enough. In the meantime, the wise course is to put safety first, leave the barriers in place and hope this winter doesn’t bring any devastating torrents of mud.