Upmanu Lall: 13,000 US dams are identified as high hazard, meaning failure would likely result in loss of life
Striking images of the Oroville crisis remind us that these dangers are not abstract problems, he writes
Editor’s Note: Upmanu Lall is the Alan and Carol Silberstein Professor of Engineering at Columbia University and the director of the Columbia Water Center. Michelle Ho is a post-doctoral research scientist at the Columbia Water Center. After this article was initially published, the Columbia Water Center said that Ho did research for the piece but did not co-author it. The views expressed here are those of the author.
At Oroville Dam in California this week, a major disaster was only one bout of heavy rains away. Luckily, the quick response of civil servants has averted a crisis, and with the water level at Lake Oroville dropping, authorities lifted the mandatory evacuation order and the nearly 200,000 evacuees made their way home.
Ominously, rain is now expected Thursday and over the weekend, and authorities are warning residents to be vigilant. The National Guard has 150 members in the area to provide support.
It is important to understand, however, that the tenuous situation surrounding the dam and its spillways was not a danger that cropped up overnight. Instead, it has been brewing for years. And it’s not an exceptional example. Of about 85,000 dams in the country, according to the National Performance of Dams database at Stanford University, nearly 13,000 – including Oroville – are identified as high hazard, meaning that a failure would likely result in loss of life.
The good news is that these problems are fixable, with adequate monitoring and funding to address dam safety issues across the country, regardless of whether the dam is owned by federal, state, local or private entities.
Historically, large federal investments in water infrastructure projects have been integral parts of economic policy that have helped to spur growth. The Oroville Dam, which lies north of Sacramento, for example, was completed in 1968 to much fanfare, being the country’s tallest dam then and now. However, in recent decades funding for such projects and their maintenance has virtually vanished, leaving many places facing dangerous situations.
The striking images of the Oroville crisis remind us that these dangers are not abstract problems. Take a moment to consider the 2,209 people who lost their lives in Johnstown, Pennsylvania, in 1889 when the South Fork Dam failed, and imagine a similar scenario of flood-control levees or dams failing in other cities.
Dam failure can lead to cascading failures of critical infrastructure such as nuclear power stations. In terms of the potential for destruction, such scenarios would be not unlike the Fukushima disaster.
Many of the large and more well-known dams in the United States – such as the Hoover Dam in Nevada and the Addicks and Barker dams near Houston, Texas (which gained some notoriety last year during the Houston floods in spring of 2016) – are owned and monitored by relatively well-funded federal agencies such as the Bureau of Reclamation and Army Corps of Engineers. They have measures in place to address safety issues.
However, the public or political discourse, rarely mentions that the greatest risks are from dams operated by state agencies, public utilities or private companies, which, according to our analysis of data from the U.S. Army Corps of Engineers National Inventory of Dams database, make up over 97% of dams in the United States.
In Oroville, local groups raised concerns 12 years ago, citing the potential for spillway failure. Their pleas were mostly ignored by federal and state officials. Unfortunately, spillway failures are a particular hazard facing a large number of dams.
As dams and other infrastructure have weakened, development on flood plains has also heightened our flood risk overall. Americans rightly take pride in our engineering ingenuity, but perhaps, to our detriment, we also underestimate our risks in many situations as a result.
Developments on flood plains have become liabilities to the National Flood Insurance Program, which sees large insurance claims and a high prevalence of repetitive loss properties. Policymakers worked to raise flood insurance rates in the aftermath of events such as Hurricane Katrina and Superstorm Sandy, efforts intended to send a signal to residents and business owners to reflect the true cost of locating in a flood plain.
Such efforts have seen congressional resistance and have had little success so far.
In a recent paper, a group of researchers, water managers, and water engineering consultants from Columbia University, Bureau of Reclamation, and Jacobs engineering outlined what is needed for the future of large water storage infrastructure in the United States. They emphasized the need for holistic planning for maintenance, monitoring, and development of water infrastructure, rather than focusing on reactionary “Band-Aid” solutions following catastrophic events.
An independent review of dams and dam safety is needed at a national scale. Permits and approvals for addressing dam safety concerns need to be streamlined to ensure issues are addressed in a timely manner.
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The authors called for a risk analysis of the portfolio of all US dams to be developed to enable targeted financing and cost allocation for dam monitoring, warning programs, emergency management and risk reduction activities.
Targeting US dams in order of risk would not only reduce dam failure risks, but also risks to water supply, and circumvents the wasteful spending of ad hoc measures by channeling available funds toward building a water infrastructure network to serve the nation.
Throughout his campaign, President Trump regularly called for improving our nation’s infrastructure. Let’s start with our dams and make millions of lives and livelihoods safer.