The lesser-known dangers of hydraulic infrastructures
Every year, hundreds of people lose their lives near hydraulic infrastructures, not due to natural disasters like floods or dam failures, but because of everyday and often mundane interactions. These accidents, though less publicized, cause as many deaths as the worst historical dam-related disasters over the past two centuries.
The activities leading to these tragedies vary: a walk along a picturesque canal, a visit to a park, or riskier behaviors such as fishing from a dam, canoeing, or even sliding down a spillway. Some of these practices, inspired by social media, expose individuals to unsuspected risks. Contrary to popular belief, alcohol is involved in only a minority of cases—less than 14% in the UK. Additionally, only 15% of drownings occur during swimming activities.
Worse still, public safety measures are often absent or inadequate, despite repeated accidents at certain locations. For example, walking or running near waterways alone accounts for 37% of deaths in the UK. Yet, the general public has almost no awareness of these dangers. The risks are visible but ignored.
Low-head dams, common in the United States, perfectly illustrate this issue. These structures, designed to regulate river levels, sometimes create a deceptive current known as a reverse roller. This phenomenon, invisible on the surface, traps swimmers in a cycle of repeated submersions, exhausting even the most experienced rescuers. Nicknamed drowning machines, these dams have caused nearly 800 documented deaths in the United States since the 1950s—a figure likely underestimated.
Accidental drownings near hydraulic infrastructures affect all ages and profiles. Men are more often victims than women, in a ratio ranging from 3:1 to 4:1 depending on the year. People aged between 60 and 74, as well as young adults aged 15 to 34, are particularly vulnerable. Incidents also cluster during the mildest months, with a peak in July, likely due to increased exposure.
Cold also plays an insidious role. Sudden immersion in water below 15 degrees Celsius can cause thermal shock within seconds, leading to loss of dexterity, impaired cognitive functions, or even cardiac arrest. Even without initial injury, the body quickly loses its abilities, making survival difficult.
Fortunately, solutions exist. Some are already implemented, such as the removal of dangerous dams or their modification to facilitate fish passage while reducing risks. Other, less costly measures include installing warning signs, fences, or flotation devices for rescues. Awareness campaigns, like those conducted in Colorado, have also proven effective.
The challenge now is to integrate these risks into the very design of infrastructures, taking into account local social behaviors. This requires an interdisciplinary approach, combining engineering, management, and an understanding of human dynamics. The progress made in dam safety shows that significant improvements are possible, provided we adopt a broader and more human-centered vision of safety.
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Cited Study
DOI: https://doi.org/10.1007/s11269-026-04771-4
Title: From Floods to Social Risks: Human-Centered Design for Safer Water Infrastructure
Journal: Water Resources Management
Publisher: Springer Science and Business Media LLC
Authors: Brian M. Crookston; Daniel Valero