Rocks And Hillsides
In the dark morning of Martin Luther King Jr. Day I heard a loud crash at my home in Sonora near the Mother Lode Fairgrounds. After minimal investigation it was assumed a cat knocked something over and I went back to bed. The crash turned out to be a boulder dislodged from the hillside adjacent to my home.
A Brief History: My house is a part of subdivided land labeled Hatler as recorded on county maps of the 1960’s. Fifty-five years ago it was property managed by county rules. Due to the steep terrain the road in the subdivision was never finished the way it is recorded on the maps. Eight other houses in the Hill Street/Gerrymander area behind the Mother Lode Fairgrounds, now in the City of Sonora’s jurisdiction, are in the shadow of the same hillside my house is. All the homes have had problems managing their piece of this hillside. The heavy rains of California’s extremely wet January 2017 caused so much damage in Tuolumne County and the State that both declared a State of Emergency. Fortunately, but unfortunately for the Biehl household (two adults and five kids,) the City of Sonora did not have much storm-related damage to warrant a State of Emergency within the city limits.
Luckily for the Biehl’s Holdrege & Kull, a firm of consulting engineers and geologists happened to have Senior engineer Richard Peevers scheduled to visit the Sonora area. Holdrege & Kull is based out of Nevada City. Upon viewing the hillside (or cliff) Peevers expressed grave concern about how close and precarious some of the rocks within the cliff were relative to the house. To address the situation Holdrege & Kull bid $20,000 to $25,000 to assess and design a fix.
History Part II: The Biehl family paid the Veterans Association to purchase this 3 bedroom 2 bath house As-Is with no disclosures for the “bargain” price of $189,000 in June 2015. Previously a veteran bought the home in 2011 but passed away. The property went back to the VA as matters were dealt with through probate at court. The escrow process with the VA was very difficult giving both my real estate agent and loan officer huge headaches. The deal closed under deadline pressure with other offers pending if it hadn’t worked out for us.
More Rocks Fall: On Friday January 27th, just five nights after the first rock fell, the same sound woke up the Biehl’s eight year-old daughter. They rushed away from the bedrooms by the cliff to the safety of the living room. Three of the children, the Ambler boys, were with their father in Modesto for the weekend. Despite challenging court matters involving recalculating child support, I called my ex-husband barely able to choke out the words to describe the fear I felt living near the unstable cliff. The divorce was six years ago and my ex-husband and I never hesitate to do what is best for the children. The room where the boys sleep is set further into the center of the house away from the cliff but even their grandfather, a general contractor, did not feel he wanted or had the experience to evaluate the hillside. The boys would just have to stay at a hotel until it was deemed safe to return by experts.
At first light, to the Biehl’s surprise, the sound they heard in the dark was a collection of stepping stone sized rocks that fell at the back of the garage.
A note about managing dirt: Retaining walls over 3 feet high have to be engineered. The little retaining wall behind the house comes in at 2.5 feet. Taller walls need bigger footings or a base big enough to support the load of a vertical wall built on it. Rockfall mesh curtains are used in some areas along roads but they must be anchored in many places and getting a drill behind the house was problematic not to mention very expensive. Removing dirt was not advised because that could undermine the private driveway above the cliff.
What Is “Safe?” Mike McConnell an excavating contractor of 25 years and a highly respected businessman, arranged a dream team meeting of experts at my house. Knowing the seriousness of the situation the three other men were: Mike Lundgren owner and Engineer of Lundgren Systems; Andy Kositsky, representing his opinion as a friend, but who is also a Senior Geotechnical engineer with Condor Earth; and Lance Crauthers of Crauthers Concrete Pumping. From 3:30PM on Wednesday, January 25th to 4:30PM the four did not offer much hope. “Bulldoze the house,” they said. “Fix the slope correctly and then build a new house. Maybe just lose the garage and back two bedrooms?”
They stayed at the site out of a desire to find a solution to “mitigate rockfall hazards” and they liked the opportunity to consult with each other. Each of the men have worked together on various projects in the Mother Lode but this cliff so near the house with a road above presented a huge challenge. Residential projects are much more high risk and often companies refuse to take on the project. The current situation would never, ever, be permitted by the City with today’s retaining wall and set-back requirements. Lundgren was the first to offer hope- he was confident the garage rocks fell due to a drainage issue. So much water came down in the storms that dirt was eroding the cliff leaving rocks exposed. The invasive Tree of Heaven (Ailanthus altissima’s) was clearly the culprit for the large rock becoming dislodged. The top of the cliff was very overgrown making true assessment impossible. It has been overgrown since it was purchased, mostly because it was all poison oak. I have long joked about renting a goat to eat the poison oak but nothing had been done yet. My husband gets a poison oak rash if he even looks at it.
A unique solution: As noted there was not enough room so the solution became how to work within the space by backfilling gravel and drainage against the house somehow. The length of the house including the garage is 54 feet, if the siding were removed and the studs doubled up and anchored to the solid foundation, a vapor barrier of wood sheeting could cover the side of the house. Then the ends of the house would be capped off by forms and cement six feet high would be floated all along the back of the house between the hillside and the house. The triangle wedge would be two feet at the bottom but 10 feet wide at the top. It would need to be a geotechnically engineered plan but it could provide a solid footing for an additional 30 foot high retaining wall on top that would block rocks from ever hitting the house again. The contractors guessed, due to the massive amount of concrete, it would cost approximately $60,000 which was half as much as any other option even if the house was removed.
Easier said than done. The first step though, before any design could be done, was to scale the cliff. Scaling means remove the vegitation and loose smaller rocks and the areas that were unstable and likely to fall. The engineering angels dispersed as quickly as they had come once they were satisfied with the solution. They went back to working to mitigate the slide at Curtis Creek Elementary, Natl’ Forest Road Projects and the like. The loose debris and vegetation were a tremendous hazard to anyone who worked below and very few like working with poison oak. I did the job that no one wanted, and I felt no one but an owner should ethically do. I refused to put a life in danger for money, I got out my rock climbing harness tied myself to various trees above the cliff and for 8 hours I removed by hand with precision and a firm motherly touch as much of the overgrowth, poison oak and loose rocks as logically possible. A free couch became “protection” for the home’s siding as I dislodged five-pound rocks down the hill toward the garage. The result by the end of the day was impressive, if not even more frightening. There was plenty of soil at the top of the cliff, very few precariously stacked rocks holding up that soil and now no more poison oak vines or roots to prevent more erosion. Rain was expected.
In hindsight sunscreen, a layer of Technu and a helmet as I worked on the cliff would have been prudent. I was mad about a lot of things and scaling the hill was tremendously satisfying. I did end up in the Emergency room with terrible poison oak (urushiol chemical) burns to my forearms- some spots were black. My face swelled some but I didn’t need a shot or prednisone, only pills which will eventually resolve my reaction. Dr. Cooper Dermatology was able to see me right away and under their treatment I am not likely to have even one scar from my exposure. My husband was not too happy with the risk I took. He remained in the house watching over his two children but began to see the necessity as I reached the halfway mark and then helped cut several medium trees down. For his help he suffered from a poison oak rash that got worse over several days. He did end up at a walk-in clinic and got a shot plus medication to manage his poison oak reaction.
It still remains to be seen if an engineering firm will take on designing and accepting liability for the footing by the house or other idea. The City did recieve the geotechnical report confirming rocks falling from the hill pose a threat to people in the house and thus the home is tagged as uninhabitable. Unfortunately since it will be another two weeks before another Geotechnical company has time to review the site and engineer plans to mitigate the rockfall hazards the Biehl family is leaving the home and moving into a rental house. We will work with Wells Fargo and Freddie Mac to resolve the outstanding mortgage on the home.
All our heartfelt thanks to the staff at Sonora Regional Medical Center, the hotel (Inns of California where I stayed for two weeks) and my friends. I would like to thank Tuolumne County Mental Health Services, located on hospital road, for their valuable support services helping people in crisis manage the stress of life. Also Young, Ward & Lothert, espically Jennifer Lothert for reasuring real estate legal advice about my options, and to all my coworkers who did a great job reporting on the storms, you are all awesome!
I am in the process of setting up a charitable fund named Sabrina’s Angels to help Mother Lode face the realities of our retaining wall issues and rebuild a safer foothill community. The fund will help homeowners assess issues related to earth movement. Do keep in mind regular home insurance does not cover any earth movement, mudslides, sink holes or landslides. If you are concerned about protecting your investment look into Landslide insurance or a “Difference In Conditions” policy. Earthquake insurance, only covers damage related to an earthquake event, flood insurance won’t cover it either. While all the extra insurance is expensive the deductable is also high and no policy covers the cost to stabalize the land- only the cost the rebuild the home.