Oakland Geology

Early on in the Covid-19 pandemic, it occurred to me that the nationwide disease outbreak was exactly like what most of us call “natural disasters” — floods, droughts, heat waves, wildfires, hurricanes, landslides, earthquakes of course, and the like. And in the literature, and on Twitter, I started to pay more attention to the specialists. Not so much the specialists in the phenomena, although those are crucial people, but the specialists who call themselves part of the disaster community: social scientists rather than natural scientists.

Those are the people who hate the term “natural disaster.” They’ll tell you “there are no natural disasters.” By that they mean an insight that galvanized me when I first read it a generation ago: “Human beings, not nature, are the cause of disaster losses. The choices that are made about where and how human development will proceed actually determine the losses that will be suffered in future disasters.”

It underlies what I do in this blog. It was in this book.

Disasters by Design came out in 1999, the outcome of a conference of disaster-related specialists sponsored by the National Science Foundation and several federal agencies. It laid out an ambitious vision of how society can deal with the disasters that happen when we get in nature’s way.

First, it pointed out that our current practices of mitigation aren’t enough. Our warning systems, building codes, and other measures succeed only in saving lives. Consider the case of hurricanes: they no longer kill many people, but they still cause record-breaking economic losses every year. Even the small ones cost more these days. Hurricanes haven’t changed much at all, but we have. The Northridge earthquake of January 1994, not such a big one, killed only a few dozen people, yet it caused more than $20 billion in insured damages alone.

And our mitigation measures have bad side effects. For example, the hurricane warning system makes people feel safer, but now it’s harder to keep them from building on the beach, from paving the dunes, from moving sand from one coast to another for short-lived patches on degrading shorelines. And in earthquake country, new structures preserve people’s lives, but the growing population is still vulnerable, living too far from jobs and served by elaborate electrical and water systems. People die less and less, but they keep paying more and more. Surely we can do better.

Disasters by Design explores how to go beyond mitigation toward a more resilient way of life, one that rolls with nature’s punches and returns to normalcy quickly. This desirable goal, “sustainable hazard mitigation,” means living politically the way we live personally, in ways our descendants won’t end up paying for. And if it’s done right, the community gains benefits beyond the insurance that the new policies provide — the people and their institutions are stronger, and wealthier too. That great work needs the help of social scientists, whose research on the people side complements the expertise on the engineering and prediction side.

The reason this book was a best-seller for its publisher, used as a textbook for a generation of practitioners and launching a movement in and beyond the disaster community, was its author. Social scientist Dennis Mileti was a gifted communicator who could hold an audience without a PowerPoint deck, a teacher who always had time for a student, and a leader who knew how to energize and drive diverse committees and teams. He went to the same conferences I do, and I sought out his talks.

Mileti died of Covid-19 on 30 January, two days before he was scheduled to get the vaccine. Last year he told a writer for the Washington Post that America’s approach to the pandemic scared him: “We have people saying, ‘It will be over soon!’ and other people saying, ‘It could be months.’ That gives the public the ability to pick the answer they like, which is the No. 1 no-no in public messaging.”

I opened my copy of his book last week — and it’s his despite having dozens of contributors — and it does not read like it’s 21 years old. The vision is still strong and the insights are still valid. You might say that means we haven’t achieved sustainable hazard mitigation, and in truth that’s a very difficult project. It takes everyone’s involvement, under skilled and patient guidance, to change a community.

But for some reason being reminded of the vision is still inspiring. And over the years I’ve seen the vision infiltrating my own piece of the disaster community, the Earth hazards sector. Tsunami specialist Lori Dengler wrote an appreciation of Mileti just last fall, which reminded me that he was involved with the ShakeOut earthquake-drill program, and before that was an advisor for this pamphlet many of you may remember from after the Loma Prieta earthquake. Dennis Mileti worked here too, for us.

And that’s just the earthquake crowd. He was involved with the full range of disasters, bringing insight into how to communicate alarms and alerts, what motivates genuine change, what steps to take beyond reciting facts at people. And yet it was a funny thing: while Mileti died of Covid-19, Disasters by Design doesn’t address disease epidemics. But over the last year I’ve read a lot of pandemic coverage, and awareness is seeping in that disease outbreaks are just part of this planet, and that if we are creating situations where animal viruses can leap to our species — imperiling ourselves by getting in nature’s way — then Covid-19 is just as much a “natural disaster” as a levee break during a flood.

It may be time for a new book that adds pandemics to the rogues gallery of disasters. It would be fitting if we could tie together the lessons learned from the pandemic and the quest to bring about sustainable hazard mitigation. Sustainability is about not just growing wisdom, but also passing wisdom forward, and Dennis Mileti did both. Let us not forget his name.

It’s been a couple years since I’ve visited and written about the Leona Quarry site. It continues to fill with houses. The plantings of local plant species are doing OK, though they’d be happier without the drought. Here’s an updated view from Burckhalter Park, which I’ve visited occasionally since 2003 just for this purpose. (The trees keep getting taller.)

The highest and final residential level, Skyview Drive, is being populated now. The rest of the land will always be open space.

However, the land won’t be exactly natural. It will be intensively maintained. That sturdy concrete flume in the foreground, for example, is there so rainwater runoff from the slopes won’t start digging gullies. The runoff goes to a collection basin at the bottom of the slope that keeps all the muddy sediment and sends the water on into Chimes Creek.

Here’s more of that impressive drainage system, on a lower slope.

What about that high rock face standing in the back? Even from this distance, it looks a little ragged, a little menacing. During my last visit, in January 2016, I was up there and it looked like this.

That crumbling rock was pouring past this temporary barrier and overfilling one of those handsome concrete troughs.

It’s a big and constant job to maintain this infrastructure. There’s always something to do. Who does it, and what happens when something major happens, like a landslide?

In developments like these, a homeowners association typically handles repairs and upkeep for community amenities like paving, play equipment and landscaping. Those aren’t demanding tasks. But what do most homeowners know about geology? For the special hazards posed by geological forces, like erosion and landslides, there’s something better: a Geologic Hazard Abatement District or GHAD.

GHADs (pronounced like “gadzooks” without the zook) are peculiar entities, created under the Beverly Act of 1979, that are set up to handle the specialized job of dealing with geologic hazards for a specific set of landowners. Formally political divisions of the state independent of cities and counties, they’re exempt from bureaucratic headaches like reviews under the California Environmental Quality Act (CEQA) or hassles with the county’s LAFCO agency (and its wretched website). They have elected Boards of Directors and can own land, impose taxes, issue bonds, exercise eminent domain and possess other superpowers. There are dozens of GHADs now, and Alameda and Contra Costa Counties are their epicenter.

What keeps GHADs from running amuck or shirking their job is their “constitution,” a detailed Plan of Control drawn up by a licensed engineering geologist that ensures the Board will act with a prudent level of care. The program of regular monitoring and maintenance is spelled out in an Engineer’s Report, prepared by a licensed geotechnical engineer. It’s a simple but powerful program that spares taxpayers the geological risk inherent in developing sites like Leona Quarry. Learn more from the California Association of GHADs.

The Leona Quarry GHAD was formed in 2005, and by now it has saved up several million dollars of landowners’ assessments for maintaining the defenses — the retaining walls, drainage facilities, native plants and so on — and for major incidents like slides, wildfires and washouts. In emergencies, the GHAD can act with funding in place, trusted experts (from ENGEO) in charge and minimal red tape.

As spelled out in the Engineer’s Report, the concrete drains are cleaned and inspected four times a year, and checked whenever rainfall exceeds an inch in 12 hours. The collection basin is mucked out whenever it fills to a certain level, and the vegetation inside is cut low whenever it grows above 5 feet high. When a wildfire swept over the north end of the upper slope last year, the GHAD sent its plant specialist out afterward to keep the native habitat in good shape, which in turn helps stabilize the slope.

A second GHAD, the Oakland Area GHAD, was established in 2006 for the small Siena Hill development off Keller Avenue. You’ve seen its rugged retaining walls with the fake-stone finish looming as you head east up Keller from Mountain Boulevard toward Sequoyah Community Church.

The builders and the city probably wouldn’t have developed this daunting location without a GHAD that enabled the homeowners to cover their own risk. And now the residents pay their annual fee of about $1500 and the City Council, meeting as the GHAD Board of Directors, spends literally three minutes a year passing a budget and keeping its hands clean of liability. Success for the developers is not certain, though, with fewer than half the lots filled after 12 years.

However, neither has failure been declared. What’s there so far looks really nice.

And from my point of view Siena Hill is a success because it exposes the Leona volcanics well, like this pretty boulder at the far end of Siena Drive.

Farther up is a fresh roadcut that displays the chaotic nature of this intriguing geologic unit, which represents a volcanic island arc of Jurassic age.

The whole thing consists of the distinctive greenish celadonite-bearing phase that I’ve found scattered all over the East Oakland hills. This is the first proper outcrop of it I’ve seen. Well worth a visit.

But enough of this stone cheesecake.

The Oakland Area GHAD is more than just a minor political curiosity; it was established with an eye toward folding in other similar developments as they come up. And it will hit the big time as the Oak Knoll development takes place over the next decade, because a whole bunch of land there, including the open space, the oak woodlands and the streambed of Rifle Range Creek, will come under the GHAD’s purview. The City Council may have to take a few more minutes from now on to manage that.

Work at Oak Knoll began in September. I am looking forward to the day when that land opens up to visitors.