Key National Dam Database Gets Major Upgrade

January 12, 2022

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The Army Corps of Engineers has recently rolled out an important set of improvements to its National Inventory of Dams that will prove useful for environmental journalists. Above, the Fort Gibson Dam on the Grand River in Oklahoma. Photo: National Inventory of Dams. Click to enlarge.

Reporter’s Toolbox: Key National Dam Database Gets Major Upgrade

By Joseph A. Davis

Dams and other water control structures have long been news on the environment beat. Now a major upgrade of the database known as the National Inventory of Dams opens new doors for reporters (and for the public).

Dams are worthy of journalists’ attention for lots of reasons. They may be built for important functions like providing water supply, irrigation, hydropower, flood control, transport or recreation.

But dams also can have negative environmental consequences, such as obstructing streamflow in unnatural ways that prevent spawning migrations of anadromous fish like salmon or shad. Or, over time, they can trap sediment, diminishing their utility and causing pollution.


The dam safety story is complicated by the

fact that many of the nation’s dams are

aging, poorly maintained, privately owned

and not engineered to today’s standards.


And dams can cause major disasters when they fail. Some do fail almost every year, although not always disastrously. The dam safety story is complicated by the fact that many of the nation’s dams are aging, poorly maintained, privately owned and not engineered to today’s standards.

Some old dams no longer serve any purpose, and are being targeted for removal. The recently passed infrastructure bill includes billions of dollars for dam safety and removal, and that will be news, too.


The data landscape

Given all that, the National Inventory of Dams, or NID, is a key tool for data journalists who want to explore dam issues at the local, state or national levels (see, for example, this major takeout from an Associated Press team in 2019).

But since the 9/11 attack two decades ago, the federal government has grown a bit paranoid about “critical infrastructure” data. As a result, public access to dam data was restricted in various ways, limiting the public benefits of the NID and also helping conceal the failures of dam safety programs to protect the public. Meanwhile, no terrorists have attacked any U.S. dams during that time.

So it’s big news for dam data geeks that the Army Corps of Engineers, who run the NID, has just rolled out an important set of improvements.

The refurbished NID is — first of all — graphically based and graphic-friendly, as opposed to the old “flat file” tabular approach. The tabular data is still there, underneath. But the data is first presented to the online user in map format, and the query engine defaults toward geographic queries.

Equally important to advanced data nerds is that you can download the data you get in several GIS formats. This is handy for two reasons. First, you can include the many map information layers native to NID. Second, you can add your own map layers, even if the NID does not have them.

Another strong point for the new NID presentation is that it is safety-aware. Some of this progress actually antedates the current roll-out. Five years ago, you could not even get the “hazard” category rating of a dam — whether its failure would endanger lives or property. Now you can. And it tells you readily whether the high-hazard dams have emergency action plans. They should, but not all do.


Using the data smartly

The NID has also grown over the years since it was first published in 1975. The current version has close to 91,000 dams. This is good for those who like data, but more dams onto the list may reflect increasing hazards (such as when development fills in around a dam).

More good news is that the NID is being integrated with the National Levee Database (also run by the Corps), important because there are lots of connections between dam safety and levee safety.

The public part of the NID is wide open to the public. But there is another layer of data behind that accessible to authorized users only, which typically means government officials. What is still unclear is who gets what information.

We wish we could report that the spiffed-up version of the NID actually increases public access to data. One of the most important new revelations are so-called inundation maps — which show what areas would be flooded by a dam failure.

Journalists in the past have had to struggle to get these maps. The new version suggests they are available, but it is not clear whether only government types can get them.

The new database seems more generous with info about dam inspections data and dam condition assessments (the latter not previously available). But when we looked, we could not see the condition assessments that we looked for — they were listed “not available” (you would think that if a failed dam would be deadly, those downstream would have a right to know whether it was crumbling).

Because most dams are private and are regulated (if at all) by the states, most of the data in the NID comes from the state level. The Corps indicates that the new NID can be more directly updated by the states. On the one hand, this could mean fresher data. On the other, some states may restrict data access even more than the feds do.

[Editor’s Note: Also see TipSheets on dam stories nationwide, on dam removal and on dam safety, as well as an earlier Toolbox on “Finding Stories With the National Inventory of Dams,” and a Toolbox on dams, impoundments and levees. Plus, for more on the Associated Press reporting, check out this guest Toolbox on the project from a member of the AP team. You can also track regular headlines on dam reporting in the news via EJToday here.]

Joseph A. Davis is a freelance writer/editor in Washington, D.C. who has been writing about the environment since 1976. He writes SEJournal Online's TipSheet, Reporter's Toolbox and Issue Backgrounder, and curates SEJ's weekday news headlines service EJToday and @EJTodayNews. Davis also directs SEJ's Freedom of Information Project and writes the WatchDog opinion column.

* From the weekly news magazine SEJournal Online, Vol. 7, No. 2. Content from each new issue of SEJournal Online is available to the public via the SEJournal Online main page. Subscribe to the e-newsletter here. And see past issues of the SEJournal archived here.

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