Some call them low head dams, others call them waterfalls, but those that know their danger give them the most accurate name: the drowning machines.
“This is nuts.”
The fireman stood by the edge of a river, talking on the phone to Civil & Construction Engineering Professor Rollin Hotchkiss, and soaking in the fact that someone just drowned. The swiftwater rescue trained fireman could not help, and someone drowned.
Across the nation, lives get stolen because an old innovation, with little purpose left, still functions in various rivers and streams. Engineers call them low head dams, a structure built in the 1800s and used primarily to harness energy. Those familiar with the harm the dams cause call them the drowning machines. Average age of victims: 20.5 years old.
Like many people, Hotchkiss used to know little about this threat to life. However, once he finished his PhD and started teaching at the University of Nebraska-Lincoln, Hotchkiss desired to create an experiment that tested his students' designing and problem-solving skills. He found a journal paper that proposed a solution to the danger associated with low head dams and thought, “If that works, that’d be great.”
Hotchkiss researched the proposal and presented the problem to his students: Low head dams. Originally used to drive saw mills, power electricity, and power industries. Now, with other energy sources in use, they only provide an aesthetic effect. More people participate in the water recreationally and the small dams often don’t alarm them. Someone gets too close and the dam sentences them to death; they get trapped in the hydraulic–water that rolls in reverse at the base of the dam, making it nearly impossible to escape.
The proposal Hotchkiss found would modify the dam, eliminate the hydraulic, and allow people to escape with the current. However, it would also likely inflict blunt force trauma bad enough to result in death.
So, Hotchkiss asked his students, what can we do to solve this problem?
No one found the answer. He took this question to his following teaching employment at Washington State University. Students searched with no success. Hotchkiss came to teach at Brigham Young University and faced the same predicament. Through his entire teaching career, few students came up with possible alterations, but no one suggested a substantial solution. He began to think, “Well, if the students can’t do it, maybe I can’t do it either.”
He continued his work anyway. With a group of graduate students, Hotchkiss discovered a solution: engineers could construct steps that would eliminate the hydraulic, keep a continuous water flow, and give victims nothing worse than some bruises. In 2018, they published the proposed solution in the Journal of Hydraulic Engineering.
With the technical work on the project done, Hotchkiss became a task force co-chair with State Disaster Relief Fund Administrator in the Recovery Branch of the Indiana Department of Homeland Security Manuela Johnson and Utah State Civil and Environmental Engineering Associate Professor Brian Crookstoon. Along with other team members, they began to map out low head dam locations and work with local government and organizations to make changes.
“Dr. Hotchkiss can be very inspired and full of energy,” Johnson said. “He brought two professional organizations together to spread out messaging and to gain information and momentum and energy … It’s really a great lesson in collaboration and innovation.”
Federal agencies, media sources, and those who experienced tragedies like this first-hand, such as the firefighter, have started turning to the task force to learn about and contribute to their work. Although the nation has many dams left to conquer, and the price to alter is costly, Hotchkiss and his team count each change they make.
Until they can eliminate this danger, his team continues to warn everyone to stay away from low head dams. No matter how tame or low the flow, and even if the person had ventured around one before, the risk never goes away. Although the problem does not affect everyone directly, Hotchkiss insists that all should regard the subject with importance.
“It’s an unknown danger, and you could be like a member of a family this summer on the Dan River in North Carolina. They took out … nine members of their family, inner tubes on a river. They didn’t see the low head dam and five of them drowned,” said Hotchkiss. “That’s why you should care.”
For videos and more information, visit our BYU dam research website.