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Because of its small size and drop, a low-head dam does not appear dangerous. In fact, it is the most dangerous type of dam. It is called the “drowning machine.”

Water going over the dam creates a strong circular current, called the backroller or the boil, at the base of the dam. The backroller can trap your boat or board and pull you under the water. Avoid low-head dams, and always carry your paddlecraft around them.

Low-head dam

Low-head dams are dangerous. Surface currents below the dam can suck paddlecraft toward the dam. Currents above the dam can sweep paddlecraft over the dam. The “boil” below the dam can swamp paddlecraft and drown paddlers.