Dams Are Not Grading High
Every four years the American Society of Civil Engineers (ASCE) produces an Infrastructure Report Card for the United States where it lists critical portions of the nation's infrastructure and the current function and needs status of these sectors. In the latest report card produced in 2013, dams received a grade of D+, which is actually quite alarming.
Many of the nation's dams were built to last 30 to 50 years, and in what were considered remote locations at the time, with then current engineering standards. Today's demands are pushing the structural limits of these aging dams.
Reasons dams are likely to fail:
- Design or construction flaws
- Sabotage - including cyber attacks
- Piping (a type of leak/seepage through or under the dam)
- Cracking from natural settling or earthquakes
- Failure from upstream dams
- Lack of maintenance and/or upkeep
New pressures and threats
Additionally, new pressures and threats that did not exist when the dams were originally built increase the risk of failure, including increased water flows with changing weather patterns and intensified natural hazard events.
This is significant because with the burgeoning population, increasing development across the nation, there has been an greater pressure on natural resources including land and water.
Consequently, communities have expanded significantly into flood plains, so major communities reside below many of these dams, posing a serious risk to citizens should the dam fail.
Just to give an idea of the potential water reach, dams often impact several communities and counties, and even cross state borders. For instance, a dam failure on the Cumberland River in Kentucky has the potential to affect multiple locations covering six counties in Tennessee, including Nashville!
Of the 84,000 dams across the nation, the ASCE indicates that more than 14,000 of them are listed as high-hazard dams, of which 2,000 are structurally deficient and in need of immediate repairs or upgrades. The number of high-hazard dams will continue to rise for the simple reason that the dams are continuing to age and without the needed repairs, the risk increases.
Human Error, Funding, or Little of Both?
A new website created by the Association of State Dam Safety Officials (ASDSO), Lessons Learned From Dam Incidents and Failures, contains a comprehensive evaluation and assessment of causes for failures, lessons learned, and competing pressures in today's society.
Almost conclusively, the primary reason they note that dams fail overall, is due to human factors. Failing to take the steps necessary to repair a known leak, or conduct proper maintenance or inspections can have dangerous future implications, placing citizens at risk.
More Than Just Human Error
However, it is more than just human error that results in a failure to make the necessary inspections or repairs, as funding has been stalled in Congress for years. This has severely hampered efforts to complete needed repairs on the more than 4,000 structurally deficient dams. Federal funding equated to approximately $15.86 million in 2011, with average state budgets at $688,000, nowhere near the estimated need of $21 billion to repair just the high-hazard dams in critical condition.
The Bigger Issue
Dams are part of the nation's critical infrastructure because of the services they provide. National infrastructure is not only something citizens rely on every day, it drives the nation's economy. As my colleague Randall discussed in his recent blog, ignoring the nation's infrastructure is no longer an option because it is likely to be part of the next disaster.
Funding for dams is on the back burner in Congress, and has been for quite some time, but the bills are coming due. As a professional emergency manager, first responder, or a concerned citizen, it is time to urge politicians to take a serious look at just what is making us vulnerable in the nation - our aging infrastructure.