PROVO, Utah (ABC4) — Researchers from Brigham Young University say they’ve created the first database of more than 13,000 low-head dams, nicknamed ‘drowning machines,’ across the nation in an effort to prevent future deaths.

After three years on the project, the BYU researchers found that low-head dams have been responsible for more deaths than all large dam failures over the last 50 years. According to a press release, more than 1,000 people have been killed in the U.S. due to these structures. Roughly a fourth of the victims were attempting to rescue someone else.

While the dams do not always look ominous, they generate strong currents at the base of their 1- to 15-foot drops that can force people under and trap them beneath the water’s surface, researchers say.

In addition to the currents, they are also difficult to see while on the water. This is because they often “spread the entire width of the waterway, so the horizon appears uninterrupted and unremarkable to nearby recreationalists — often until it’s too late,” the release said.

A map covered in green and yellow dots marking low-head dams across a U.S. map.

Researchers from BYU attempted to find these low-head dams and catalog them in a database since many are no longer maintained or owned by any group or government.

Students, researchers and members of a BYU-led task force contacted state governments, searched on Google Earth for white lines across rivers, and relied on retired U.S. Army Corps Engineer Bruce Rogers to identify low-head dams across the nation.

The researchers cataloged more than 13,000 low-head dams, 503 of which are in Utah, according to the university. Researchers say this is a great start to the database but that there are likely more dams that have yet to be recorded.

For the project’s leader, Professor Rollin Hotchkiss, this research is more than merely documenting the locations of dams, it’s about saving lives.

“The heart-rending stories of families impacted by drownings at low-head dams motivated me to do something to help,” Hotchkiss said. “It doesn’t have to happen.”

The research was shared at the Dam Safety Conference last month and team members hope the database will be helpful to The Army Corps of Engineers in the future. Hotchkiss also has developed multiple designs that could reduce the danger of these dams.