21 April 2013

The "Moving Mountain" on Carbon Canyon Road in 1938

The Brea portion of Carbon Canyon is much steeper and hillier than that on the Chino Hills side.  The engineering of Carbon Canyon Road has been presented problems over the years, especially when heavy winter rains (hardly an issue this winter, as rainfall barely reached a paltry 5 inches--meaning get ready for potential fire hazards) pummel the area.

In the winter of 1937-38, some of the worst flooding ever recorded in the southern California area took place.  Along the Santa Ana River, many lives were lost and houses destroyed, especially in the Atwood community, now part of Placentia.  In La Cañada-Flintridge, at the base of the San Gabriel Mountains, flooding and mudslides took a heavy toll.  Damage and destruction were found throughout the region.  Higher than usual precipitation continued into the spring, moreover.

The 27 June 1938 issue of the Los Angeles Times featured an article titled "New 'Moving Mountain' Perils Orange County Road."  This was the second county highway to have the problem of major sliding of earth, though the other was not specified.  In any case, Carbon Canyon Road was the threatened roadway receiving attention in this piece, which reported that the problem "was asuming major proportions, as ahuge mass of each apparently is ready to move across the Carbon Canyon highway near here."

The paper went on to note that "the moving hill first started some distance from the highway above the Ed Gaines ranch."  For those who've read other posts on this blog about Canyon history, the name Ed Gaines will be recalled as being the owner of a large stock ranch in what is now Olinda Village.  The article contined that the problem "was not viewed with alarm by engineers. but since the movement started the hill has plowed up more than forty acres of ground and seems to be preparing to wipe out a small hill and possibly move across the highway."

While observing that the road was not yet affected by the sliding mass, the Times stated that, "at times tons of earth have blocked about half of the right of way and have been removed."  In addition to this, "the earth slide has opened many huge fissures and has wiped out a small plateau of about five acres in its downward course."  Engineers studying the situaton estimated that the ground, soaked by the heavy rains, would continue their slide.

In hilly, steep terrain, the composition of the soil is such that landslides occur with some frequency.  In the winter of 2004-05, one of the wettest in recent history, some significant landslides occurred at various points along Carbon Canyon Road, especially in Brea.  There is a major steep cut in the hills just west of Olinda Village that, a few years back, was the subject of stabilization attempts.  The failure of certain slopes is always a real danger.

In fact, this question is now pertinent with the proposed Madrona housing development (formerly known as Canyon Crest) of 162 residences on the north side of Carbon Canyon Road in the hills east of Olinda Village and west of Sleepy Hollow.

The propensity for land slides have been pointed out frequent as an ongoing concern as the Canyon Crest/Madrona saga, senselesly grandfathered in its present state from outdated, outmoded and obsolete general and specific plans for the Canyon, plods along.  Several areas of the proposed project site have been determined to be potentially subject to slope failure, with cutting and filling being a major part of the project, even as the newest iteration seeks to slightly reduce the number of affected areas.

Now, of course, engineering technology is light years better now than it was 75 years ago, but we know from recent experience that building in some hilly terrain still leads to slides and failures and, as the Madrona project, moves to a council decision on the 2008 appeal of the then-Canyon Crest project, which was narrowly approved 3-2 by the Planning Commission, this is one of several areas of concern that will be focused on as the council vote, probably in June, nears.


Anonymous said...

Again, thanks for the blog! It's nice to come here every few weeks or so to see what's going on!

I think that part of CC Road is going to slide whether there's development there or not. Not that I want a bunch of development, but I know that while the price of having overdelopment is steep, there's also a price for stifling development on land that no longer serves to be profitable in agriculture (or is prohibited from being profitable by over-regulation!). It can backfire.

Mud slides in canyons are physics and inevitable. My dad as a cattle ranch manager one time planned on carving a jeep road on a hillside to make it easier for him to spread hay. He didn't get around to it before winter. It was a big winter, and the hill slid. My dad said, "If I'd carved the road, I would have always blamed the slide on that."

It's just something to think about, with regard to development causing slides. And I know you'll think I'm crazy (I am!), but I'm perfectly ambivalent about the towers. To tell you the truth, esthetically, I love them as futuristic, man-made sculptures. But I think it's pipe dreaming to assume that a windpower plant is going to keep them humming enough to justify their existence (isn't that the expectation?), or even think it's necessary to go to such great lenghts for such problematic "earth-friendly" energy production. And I don't like the EMFs -- they need to be far away.

Good blog, thank you so much for good reading!

prs said...

Hi anonymous, thanks for the comment and for the regular visits. Totally agree that slides are part of canyon geography; the point was more about building homes in slide-prone areas that are also subject to fire, as well as take away increasingly rare open space AND create more traffic on a two-lane road that can't be widened and is already very busy during commute times, etc. Also agreed that the towers are not as terrifying as my tongue-in-cheek term might imply. Whether the clean energy from wind is not as much a solution as has been touted, something has to be done to wean us off the overreliance on fossil fuels. It may not be this and there will be testimony at these final CPUC hearings about whether the Section 8 portion is needed. Thanks again for the support!