Avoid the Drowning Machine: Low Head Dam Public Safety Awareness Month

The American Society of Civil Engineers (ASCE) has declared April to be

Low Head Dam Public Safety Awareness Month.

Click the image above to visit the damsafety.org and learn more about public safety at dams.

According to ASCE, "A low head dam is a manufactured structure, built in a river or stream channel, extending fully across the banks. A low head dam is designed and built such that water flows continuously over the crest from bank to bank. If water levels rise downstream, a submerged hydraulic jump can form which produces an upstream directed current that traps any recreationist who might go over the dam."

Low head dams are often colloquially known as "drowning machines" (link courtesy Iowa DNR) due to the hazard they pose to swimmers, kayakers, and other recreationalists, who may not recognize the structures or be aware of the turbulent currents they can cause, which are extremely difficult to escape.

Click here to see a short documentary on the hazards of low head dams in Indiana and elsewhere from local public television station WFYI - "Over, Under, Gone: The Killer in our Rivers."

Can you spot the potentially deadly low head dam in the first of the following two photos?

Upstream side of a Low Head Dam

Downstream side of a Low Head Dam

As part of our mission to build a Weather Ready Nation, NWS Louisville is a proud participant in the Kentucky and Indiana state teams of Silver Jackets, an interagency partnership for natural hazard mitigation and solutions sponsored by the U.S. Army Corps of Engineers. NWS Louisville reminds you to respect the power of water at all times, and Turn Around, Don't Drown!