Pointing to accidents and fatalities on Colorado’s waterways due to the structures, the state’s Department of Natural Resources on Wednesday announced a new effort involving signage, emergency responder education, and public outreach about the dangers of low head dams.

“Colorado has seen an increase in outdoor recreation in recent years, particularly on our rivers and streams, but this has also led to tragic fatalities on some of our low head dam structures,” said Dan Gibbs, the department’s executive director. “These fatal accidents are avoidable and are a strong motivation for our Department to increase our public outreach and education initiatives.”

Low head dams span the width of a stream or river to divert water for agriculture, prevent degradation or serve as recreational amenities. Although they are small structures that raise the water level upstream slightly, DNR acknowledged they can be “drowning machines” because of the recirculating currents that can trap people who are unaware.

There have been 13 fatalities since 1986 due to low head dams, with the ages of victims generally between 13 and 30 years. At one dam on the South Platte River, DNR and a private company installed warning signs after two deaths since 2016.

A 2019 inventory study identified more than 1,100 such structures in Colorado, and DNR now displays an interactive map of low head dams on its website. The department’s efforts around dam safety are funded in part through a $20,000 grant from the Federal Emergency Management Agency.