Friday, August 8, 2014

Did We Build in the Right Place?

A story attributed to the Associated Press this week (Link Here) talks about an immigrant family living in a beautiful new house in a “mountainside Salt Lake City suburb huddled late at night with neighbors and a local Mormon leader, praying in vain that a fractured ridge above their home would hold steady during a storm and prevent boulders and gravel from crashing through the back door.”

After witnessing the hillside give way and destroy the family’s home, the article quotes a neighbor as saying, “It's really scary, but it's not shocking either… It makes me wonder: Did we build in the right place?"

The North Salt Lake Landslides, August 2014 (Photo credit here)

Did we build in the right place?

Historic Mormon leader Brigham Young is said to have proclaimed, when his small advance party of pioneers reached the mouth of a canyon high above the Salt Lake Valley in 1847, “This is the right place.”  Young, however, had the common sense to add the following instruction to his team leaders, “Drive on.”  Over the next few months, he proceeded to establish what would become a major city centered in a relatively flat area at the northern end of the Salt Lake Valley.  Over the decades that followed, most development (due to its agrarian focus) extended south and west of the “downtown” area, where irrigated farmland soon provided nutrition and employment for a growing population.

It wasn’t long, however, before this population included a large number of merchants, government leaders, professionals and others for whom there was no reason to live near a farm.  So homes on smaller tracts were built and, as they spread into areas less-desirable for farms (e.g., on the slopes of the nearby Wasatch Mountains), it became a symbol of status in the community to build higher and higher into the foothills north and east of the city.  In fact, to this day, the most desirable (and pricey) neighborhoods in Utah are built high on the mountainside where the sunset views over the Great Salt Lake are, I must admit, absolutely stunning.

As a graduate student in Geography and Urban Planning at the University of Utah, I took a (literal) field trip around the Salt Lake Valley with my geologic hazards class and our engineer instructor.  The purpose of the trip was specifically to address building and development in areas prone to earthquakes and landslides.  There are three things I remember most about that day.  The first was standing in front of a government building downtown (one that housed, at the time, the civil defense and emergency coordination activities for the state) and the professor making note of the fact that the towering structure was built literally on 25 foot stilts—open columns that, during an earthquake, would easily collapse, sending the whole building to the ground. 

I also recall standing near the mouths of canyons to the south end of the valley, making note of very visible (and recent) fault scarps that ran literally through high-end neighborhoods.  Some of the yards contained large boulders that, at some point in the past, had come from the rock face above.  We wondered out loud what it must have been like to watch an automobile-sized piece of granite roll down 2,000 feet of mountainside toward the spot where we were standing.

But when I heard the news of this latest geologic mishap a few days ago, I recalled vividly one of the final stops we made, standing high on the hillside adjacent to the Wasatch Mountains as our instructor pointed down, along the range of mountains to a brand-new neighborhood of expensive houses.  This new development, like so many others, was built on what appeared to be gently rolling hills extending from the mountainside to the east and ending a mile or two (or more) to the west where they merged with the valley floor.  This part of the valley is benignly called the “foothills” and, as I noted, the most coveted place to live.

We were about to get another, very important lesson akin to “things aren’t always what they  appear to be.”  As we stood looking together across these hills, the instructor told us to ignore the houses and the trees and, instead, focus on the landforms themselves.  When we did, it was immediately apparent that these houses—hundreds of them—were built on the remnants of massive landslides that had occurred sometime far enough in the past that the rough edges had been worn down by erosion. “It happened before,” he reminded us, “So what’s to stop it from happening again?”

Which brings me back to something I said in an earlier post and have reiterated since.  Location is everything.  This is particularly true for earthquakes and landslides where, no matter the precautions you take, the only way to truly avoid damage to homes, lives and livelihood, is to avoid building in hazard-prone areas in the first place. 

So here’s the answer to the neighbor’s question, “Did we build in the right place?”  

No matter the supposed expertise that may have declared it “safe,” and regardless of the governmental entities who, for some reason, approved development on the site, the answer is a resounding “no.” I’ll forgive an individual homeowner’s naiveté about geologic engineering and I feel sorry for the families whose houses were destroyed. 

However, like my professor said, as he summarized the field trip that day, it’s up to the planners and engineers who know better to speak up and prevent zealous government officials and (dare I say greedy?) developers from taking risks with the lives of unknowing home buyers who simply want to enjoy the sunset view of the lake.