Seattle City and Light, Diablo Dam | Dam Safety 2019

Dam Safety Awareness Day

How is your community dam serving you in crisis?

As more and more communities address the resilience of their citizens and their infrastructure, certain dams are going to be identified as critical infrastructure for their ability to provide water supply, electricity or flood control while the community recovers from disasters. The dams will be needed to provide ongoing safety and security to the community and remain in service beyond the design disaster. So, on National Dam Safety Awareness Day, take a second look at the dams serving your community. They may play a bigger role in your community’s resilience than you think.

National Dam Safety Awareness Day was created to commemorate the tragic loss of life following the South Fork Dam Failure near Johnston, Pennsylvania, in 1889. This tragic dam failure began a movement that ultimately resulted in passage of the National Dam Safety Act in October 1996. It’s hard to believe it took over 100 years to establish a program of dam safety following such a horrific event. The dam safety industry continues to face new obstacles and opportunities in our quest for improving the safety of these critical infrastructure systems. 

In 2019, the Association of State Dam Safety Officials released an updated cost estimate for the 90,000 dams that need repair in the United States. It comes with an eye-popping $70 billion dollar price tag. This is just the price to improve the safety of the dam to prevent an uncontrolled release of water. But, the price could actually be much higher for certain dams. 

In 2014, the American Society of Civil Engineers formed a new division  ̶  The Infrastructure Resilience Division  ̶  with the stated purpose of developing a unified approach in advancing concepts of resiliency within lifeline and infrastructure systems. What does resiliency have to do with dams?  Ponder this scenario...

A high hazard water supply dam is deemed “unsafe” under a significant earthquake load due to the underlying geologic formation and/or its original design. The dam is rehabilitated so that, under the design earthquake, it does not result in the uncontrolled release of water. Also, an emergency drawdown is installed so the dam can be dewatered quickly and safely for repair. This is a sound and prudent approach for keeping the dam “safe.” But, other consequences will happen in the community following this earthquake. Fires will need to be fought, hospitals will need a steady source of water, and a suddenly homeless population will need water for drinking and sanitation. 

A disconnect exists in maintaining the resiliency of a community following an earthquake and current dam safety practices. For certain dams, they are critical, lifeline infrastructure and must provide ongoing, water service to meet other community needs following the design disaster. The dam may be the only source of water and water pressure to fight fires and recover from the disaster. With our changing climate, potential earthquakes and more unpredictable weather patterns, the safety and resilience of our dams are more important than ever.