Wednesday, February 15, 2017
For several recent days, the eyes of the nation were on the Oroville Dam in Northern California. A rainstorm atop heavy snowpack threatened to overfill Lake Oroville, and the outflows began to erode the dam’s primary spillway. Dam managers switched to a backup spillway, which had never been used, but it, too, began to fail within hours. That led to the evacuation of 200,000 people, and to the California Department of Water Resource’s Facebook page becoming far more popular than the department has ever wanted it to be. Thankfully, the erosion in the primary spillway has stabilized, and the threat seems to have abated.
(Image from Wikimedia Commons; William Croyle (California DWR), photographer)
But we should not relax too much, because there are tens of thousands of dams across the nation, and many of them would seem like better disaster candidates than Oroville. Unlike most dams, Oroville Dam gets a lot of attention; it holds back the key water storage reservoir for California’s State Water Project, which provides water to millions of people in the Los Angeles and San Diego metropolitan areas and to smaller but still substantial numbers of people in the San Francisco Bay area. For urban water users in California, no other dam is more important—and it also is an important source of agricultural water supplies. Its continued integrity is worth billions of dollars to water users across the much of the state. It also is important to the Sacramento metropolitan area, much of which sits on low ground and behind aging levees about seventy-five miles downstream.
Oroville Dam’s operations are also subject to higher-than-normal levels of regulatory oversight. Because the dam generates hydropower, the state of California needs an operating license from the Federal Energy Regulatory Commission, and FERC licenses periodically come up for renewal. FERC’s licensing process provides an opportunity for reconsidering—among many other issues—the safety impacts of continued dam operation, and it also provides participation opportunities for many other government agencies, NGOs, and individual members of the public. Indeed, it was during the most recent relicensing process, in 2005, that environmental groups warned of the scenario that unfolded over the past week.
Those warnings went unheeded, but at least there was a public forum for them to be offered. That is more than can be said for most of the United States’ dams. The vast majority of those dams do not generate hydropower and are not subject to FERC regulation. Regulatory oversight, to the extent it exists, instead comes from state law. In a recent study, The Nature Conservancy’s Colin Apse and I described what we learned about those state laws (I’ve taken out the footnotes but linked to several source documents):
[I]n most states, a dam, once built, is grandfathered from the requirements of environmental laws. Many of those dams were constructed before significant environmental laws existed or, at least, before those laws were acknowledged and enforced. The environmental laws of many states therefore have never really applied to most of those states’ dams. Indeed, in many states, the only way environmental laws would be triggered is if a dam owner proposes to do something different with a dam — like, for example, add hydropower capacity or take the dam out.
On paper, state regulation of dam safety is more robust. Most states have safety standards and laws requiring periodic inspection of dams, and safety reviews ought to present opportunities to reexamine the operations or even existence of dams. But on closer examination, those schemes also often appear — in the words of one leading expert — “pitiful.” Maine, for example, has robust requirements for dam inspections but has never adequately funded the inspection program. Texas recently passed legislation exempting many dams from its inspection program, and Texas law, at least as currently interpreted, also limits the public’s ability to even access information about dam hazards. Many other states face similar circumstances. Dams do age and fail, but because of these oversight gaps, smaller dam owners in many states are all but legally invisible so long as nothing goes drastically wrong. Indeed, there are thousands of state-regulated dams whose owners aren’t even known.
To make matters worse, most dams lack the kind of constituency that the Oroville Dam has. Many dams produce little economic value, and unless people downstream realize the safety risks the dams pose, no one is likely to demand, let alone offer money for, their continued maintenance and upkeep. For the non-negligible percentage of the United States’ dams with unknown ownership, maintenance is particularly unlikely. State-regulated dams are generally small, while the Oroville Dam is the nation’s tallest, so the risks are of different orders of magnitude. But that does not mean they are non-existent. Even small dams can cause big problems.
So what should we do about this situation? At the Oroville Dam, the solution will likely involving pouring a lot more concrete. Sometimes that will be the appropriate thing to do. Indeed, as Colin and I argued, there are places where the most sensible thing to do with a dam will be to fix it up and add some turbines. But for thousands of dams, a more sensible alternative is removal. If a dam provides only marginal economic benefits—or no benefit at all—to its owners, causes environmental problems, and is a safety risk, it ought to come out. Similarly, states ought to take a much closer look at their dam safety programs. If a closely-watched dam like Oroville can turn into a menace, it’s concerning to think about all the aging infrastructure that no one is watching.
People often think of dam removal primarily as a method of environmental restoration, and dam removals are indeed an effective way to restore damaged environments. But taking out dams, as well as reinvesting in the ones that remain, also can be a good way to keep people safe.
- Dave Owen