How can frazil ice block water-intake structures?

Frazil ice consists of small, thin, disk-shaped ice particles that form in turbulent, supercooled river water. Because these particles are inherently unstable and actively growing in supercooled conditions, they possess a strong tendency to stick to one another and to any surface that is cooled below the freezing point.1

When these ice particles come into contact with water-intake structures, they adhere to the surfaces by freezing. Over time, this process leads to the buildup of large, porous accumulations of ice. These masses can effectively obstruct the intake, significantly restricting or completely blocking the flow of water into the structure.1