The March 2019 failure of Nebraska’s Spencer Dam has a lot of public officials wondering the same thing, and justifiably so. There are now 90,000 dams nationwide, and a high number of them have received less than favorable Dam Safety Action Classification (DSAC) ratings from the U.S. Army Corps of Engineers (USACE). In fact, as of 2016, the federal government said there were approximately 15,000 U.S. dams classified as having high-hazard potential (HHP), meaning that their failure could result in loss of life. So is your community, city or county among those at an increased risk, and what can you do to better protect local residents from dam-related emergencies?
For starters, face the facts. No dam is flood proof. They are man-made structures that, with age, and potentially even the effects of climate change and global warming (if you agree with the theory) clearly have an increased risk of failure. According to the Association of State Dam Safety Officials (ASDSO), such failures are most likely to happen for one of five reasons: 1) overtopping caused by water spilling over the top of the dam; 2) foundation defects (these cause about 30% of all dam failures); 3) cracking caused by movements like the natural settling of the dam; 4) inadequate maintenance and upkeep; and 5) piping, i.e., when seepage through a dam is not properly filtered and soil particles continue to progress, forming sinkholes in the dam. Aside from dam failure, it is also important to note that a dam operator might be forced to release excess water downstream in order to relieve pressure from the dam. This too, though oftentimes necessary, might pose a risk to those who live and work in the path of the raging waters.