Across the flatlands of the American Midwest, concrete low-head dams served for decades as important tools in flood management, as gauging stations, and for irrigation. They’re also highly dangerous—nicknamed “drowning machines” by some water management agencies.
The hydrodynamics caused by the fast flow off the dam’s ledge result in water moving in a reverse circular motion between the dam wall and the water boil point, typically a couple of yards downstream. Anything—or anyone—caught in the current gets pushed underwater, turned up and pushed back down again. Lifejackets lose their buoyancy and are rendered nearly useless by air bubbles that fill the water.
Difficult to see from upstream, low-head dams have drowned hundreds of people across the country over the past decade. Iowa, Pennsylvania, and Minnesota are together responsible for one-third of all low-head dam drownings in the United States, according to a 2015 study by researchers at Brigham Young University. A single dam in Harrisburg, Pennsylvania, has claimed at least 29 lives. In Iowa, almost 200 people have drowned at the hands of low-head dams—a third of them in the last two decades alone.
But in Springfield, Ohio—and in other towns across the Midwest—efforts are underway to rid rivers of these treacherous structures. Doing so brings additional benefits by opening up rivers to recreation.
Building a whitewater run in Ohio
When rafter and entrepreneur John Loftis returned to his native Ohio after five years chasing whitewater around northwestern Colorado, he wondered whether the thrills he had experienced out West might somehow be replicated in his own backyard. He had plans to develop a six-mile stretch of Buck Creek, a small river that runs through Springfield downstream of a major dam and reservoir run by the U.S. Army Corps of Engineers.
But a host of obstacles—literal and bureaucratic—initially stood in his path. Chief among them were three low-head dams running from bank to bank, installed decades ago to control flooding. After the tragic drowning of a child at one of the dams in 2008, the community called for a change. With the Corps of Engineers on board, Loftis and his team set to work converting and removing the dams beginning in 2009.
Loftis, who has a background in construction, spent months knee-deep in the river. His team used excavating machines to modify and eliminate several dams entirely before strategically positioning a mix of boulders and concrete to create desired wave effects. “We were there every day in the water, wedging rocks with prybars,” he says.
(Deteriorating dams: The problem America has neglected for too long.)
His 15-hour workdays paid off: Today, Buck Creek is the centerpiece of the ECO Sports Corridor, which offers eight whitewater features that culminate at the Snyder Whitewater Play Park, where a series of four drops attracts paddlers from half a dozen states around the region. Scheduled water releases from the Buck Creek State Park reservoir upstream result in a reliable source of quality rapids for recreationists on weekends every fall. These combined efforts have helped put back life in a town hollowed out by the loss of thousands of manufacturing jobs.
Removing low-head dams
From Colorado to Indiana to Maine, municipal authorities, environmentalists, and engineers are embarking on projects to map and remove low-head dams. Of the 26 states that removed dams in 2019, a third were Midwestern.
“In recent years, we’ve definitely started to see an uptick [in removals] in the Midwest and Great Lakes regions,” says Jessie Thomas-Blate, director of river restoration at American Rivers, a nonprofit working to return rivers to their natural states.
For water enthusiasts and associated businesses, the benefits of free-flowing waterways are obvious. In places like Dayton, Ohio; metro Chicago; and Grand Rapids, Michigan—regions with a combined population in the millions—community leaders and municipalities are spending millions of dollars converting low-head dams into whitewater recreation features as part of broader plans to boost their local economies. For serious wave fanatics, the whitewater competitions of the Summer Iowa Games are scheduled to be held at the Charles City Whitewater Park in June.
Removing the dams has also resulted in ecological benefits—such as reintroduction programs for a host of fish and amphibians, including the hellbender salamander, the country’s largest. Removing dam hazards and reestablishing natural river flow creates safer fishing opportunities for anglers, as well.
(Huge dam demolition could save salmon on the edge of extinction.)
Finding and mapping the “drowning machines”
But challenges abound. An unknown number of low-head dams—perhaps tens of thousands—still block waterways across the U.S. Many were abandoned decades ago by private owners who no longer operate, meaning that estimating their total number, or even how many remain unaccounted for, is guesswork. This, and the growing frequency of people taking to rivers to recreate, have increased the need to find and map their locations.
The authors of the Brigham Young University study, however, have taken on the challenge by establishing a project to find and develop a database of dams, using AI software and Google Earth Pro. Manuela Johnson, leader of the Indiana Silver Jackets, a voluntary, inter-agency team working on solutions to waterway hazards, has helped develop the software which, so far, has delivered “about 90 percent accuracy.” For river users who wish to contribute to the database, this app allows people to geotag and photograph low-head dams.
(Two-thirds of the longest rivers no longer flow freely—and it's harming us.)
Still, not everyone is pleased. Some fishermen, drawn to the dams by fish congregating in pools at their base, and locals, who enjoy viewing the beautiful (yet deadly) waterfalls, remain opposed to their removal.
As social-distancing mandates ease and recreationists prepare to take to rivers, the risk of life-endangering injury could spike over the summer. Johnson advises that paddlers and river users check water levels on the U.S. Geological Survey website before going out.
But for those taking care, renewed opportunity awaits—right in their backyards.