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‘Drowning machines’: Low-head dams an unexpected killer

On July 9, five people went for a morning kayak trip on the Arkansas River.

Rain had swollen the river. It was 7 feet higher than normal and had water flowing faster than 6 mph – a swift current for the Arkansas.

They were on the river for only a few minutes when they hit churning water under the 21st Street bridge.

The kayakers didn’t see small yellow signs on the bridge above warning of the dam below.

They didn’t know they were heading toward what experts call a “drowning machine” – a low-head dam. Such dams have killed more than 340 people across the country since 1980.

Kansas has an estimated 100 such dams, but no state regulations for warning signs. Local officials pushing the river as a recreation destination are just now considering ways to add and improve warning signs.

When one of the women in the group went over the 1.5- to 2-foot drop, her kayak tipped and she fell out. She was not wearing a life jacket.

Brian Bergkamp, a 24-year-old seminarian from Garden Plain, tried to help.

From his kayak, he threw the woman the life jacket she had lost.

But Bergkamp’s kayak overturned.

Somehow, the woman was able to get out of the current. No one saw Bergkamp after he went under.

His body was found nearly three weeks later, 6 miles down the river.

‘Drowning machines’

Because low-head dams don’t look dangerous, people underestimate the power behind them and go over them – even if they see the dams first.

The hydrology behind low-head dams is why experts call them “drowning machines.”

As water flows over the top of the dam, it creates a circular current on the down-river side that pulls people and debris down, up and back toward the dam in an unrelenting cycle.

“Low-head dams harbor strong hidden rotating reverse currents that swimmers just simply cannot overcome,” said Bruce Tschantz, who studies low-head dams and the deaths related to them. Tschantz is the former chief of federal dam safety for the Federal Emergency Management Agency and professor emeritus in the University of Tennessee’s civil and environmental engineering department.

This circular motion can put hundreds of pounds of pressure on a person in the water, he said.

“It’s like a washing machine. It just keeps recycling you.”

Nationwide, at least 340 deaths have been reported at dams like the one where Bergkamp drowned since 1980, according to Tschantz’s research.

So far this year, 25 deaths have been reported at low-head dams nationwide. Most of the deaths occur from April to August.

An increasing number of deaths at dams in recent years may be attributed to more people kayaking and canoeing, Tschantz said. At least half of drowning deaths at dams are from kayakers and canoeists.

Changing flow conditions at dams make them unpredictable day to day.

 

“The greater the flow, the more dangerous it becomes until it’s totally flooding over the dam and there’s no danger at all because the water doesn’t even recognize the dam,” Tschantz said.

“It’s the in-between of the extremes that causes dangerous conditions,” he said.

Witnesses say Bergkamp was wearing his life jacket. But in situations like this, life jackets don’t help much.

The water at the base of these dams has low buoyancy because of increased aeration – up to 30 percent air bubbles, Tschantz said.

About 60 percent of people reported to have died at dams were not wearing a personal floatation device, and about 40 percent were, according to Tschantz’s research.

“Even life jackets are not adequate to keep you afloat,” he said. “It’s like jumping out of an airplane with no parachute.”

Tschantz still recommends always wearing a life jacket.

“The bottom line is: Don’t go over a dam,” he said.

Four dams

Water rescues at low-head dams can be risky.

People who try to rescue others often become victims themselves, Tschantz said: Up to 25 percent of victims at dams are rescuers.

“When it’s raging like that, we can’t train in it. It’s too dangerous,” said Brent Holman, rescue captain for Wichita Fire Department Station 4, who helped in rescue efforts for Bergkamp. “We do what we can, but unfortunately, usually it’s not a good outcome.”

“If you get caught in one of those that’s violent enough, you can’t get out of it. It’s going to hold you until it’s good and ready to let you go,” Holman said.

“In any swiftwater situations, with all the training we do, that makes me the most nervous. Even with all the gear we have, it still makes me nervous because there’s no power like moving water. It gets underestimated. That’s why people get in trouble.”

The Arkansas River in Wichita has two dams. The Little Arkansas River also has two.

Only one, the Lincoln Street dam on the Arkansas, has a boat passage on the side that allows kayakers to pass safely and fish to migrate up the river. A new dam with the passage was completed in 2012.

Another, the Central Avenue dam on the Little Arkansas, has a log boom to help catch driftwood and warn boaters.

There also are dams at the Keeper of the Plains and at 21st Street, where Bergkamp drowned in July. The 21st Street dam was built in the 1970s to slow floodwaters from the Big Ditch.

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Holman said he’s seen people get in trouble at the dam by the Keeper of the Plains, and he was in a group that had a training accident at the 21st Street dam about 20 years ago.

The rescue workers training there lost one of their boats and a radio, but all the people made it safely to shore.

When an accident occurs, the team operates in rescue mode for about 30 minutes and then goes into recovery mode. When it’s cold water, the rescue mode lasts longer.

“We do the best we can, but it’s like looking for a needle in a haystack and it’s moving,” Holman said. “You just don’t know where they’re going to end up. Then what really sucks is you don’t have closure.”

The addition of a boat passage at the Lincoln Street dam has helped rescue teams, but Holman said the department needs a boat ramp south of the Lincoln Street dam to improve access.

The 21st Street dam, where Bergkamp drowned, is especially dangerous because it’s actually four low-head dams that span across the pillars under the bridge, Holman said.

“A lot of people don’t even know it’s there,” he said. “You can see it if you’re on the walking path. But if you go north of there, there’s not too much in the way of signage to warn people.

“The signs are small and they’re rusty,” he said. “There need to be huge signs. There are big signs at Lincoln Street now, and there need to be big signs (at 21st Street) – maybe a cable stretched across, too. … When it’s going, it’s a churning, nasty machine. And it doesn’t discriminate. It’s going to kick you around. It doesn’t care who you are or how strong you are. It’s going to win.”

Signs for safety

Over the last several years, local officials have encouraged more people to get out on the Arkansas River.

In July, the Arkansas was named a designated National Water Trail, an award from the U.S. National Park Service that rates the river from Great Bend to the Oklahoma border as one of the best recreational rivers in the nation.

Now, after Bergkamp’s death, the city hopes to catch up its safety measures.

Asked about any immediate plans for new signs at Wichita’s dams – including the dam at 21st Street – Troy Houtman, director of parks and recreation for the city, said some new signs are planned in the next four to six weeks.

He’s not sure if signs will be at all the dams. “We haven’t even done inventory,” he said.

The Arkansas River Coalition, a nonprofit that aims to protect and promote enjoyment of the river, says on its online River Guide to avoid the hazardous low-head dam under the 21st Street bridge.

Signs should be erected in locations where swimmers and boaters alike can easily read them from upstream or downstream, said Tschantz, who studies low-head dams and the deaths surrounding them.

“That would be the very minimum thing to do,” he said.

The Kansas Department of Agriculture’s division of water resources has no requirements for signs warning about dams, according to Terry Medley, water structures program manager.

Kansas’ dam safety program, like many across the country, focuses more on structural integrity of dams rather than public safety and drowning.

In Pennsylvania, law requires signs 100 to 200 feet upstream and downstream and on both sides of a river, depending on the size of the dam. Another precaution is stringing buoys on either side of the dam in conjunction with the signs, Tschantz said.

There should also be signs pointing to portages or places where kayakers and others can get out, he said.

The Lincoln Street dam, where the boat passage is located, has large signs directing kayakers to the passage so they don’t go over the dam.

Sen. Dan Kerschen, R-Garden Plain, vice chair of the Senate committee on natural resources, said it’s worth looking into the state requiring signs at dams.

“If there’s some information out there, let’s take a look and have a discussion about that,” Kerschen said.

Breaking the cycle

Some states are removing dams altogether because of the public danger and the effect of dams on the ability of fish, like trout, to migrate upstream.

According to American Rivers, a national river conservation organization, more than 350 dams were removed across the U.S. between 2010 and 2015.

Dam owners and municipalities can dump rocks below the dam to break up the boil, put in concrete steps as a series of falls, or build a series of pools and drops, Tschantz said.

The city’s capital improvement plan for 10 years into the future includes a boat passage at the 21st Street dam similar to the one at Lincoln.

“We could try to do the same (at 21st Street),” said City Engineer Gary Janzen. “At some point, we can’t protect everyone. Unless we physically put something in the river like the log boom, the idea is we would direct them to the boat pass and then that no longer is an issue – if and when we do that.”

He estimates it could cost more than $1 million to put a boat passage in at the 21st Street dam.

Houtman, with the parks department, said no money is set aside for that.

“We always want more activities and people enjoying nature and getting involved,” Houtman said.

“With that comes to light things ignored over the years, operations and maintenance of the river system. Nobody has really put pen to paper on this, and it’s forcing us to look at it a little bit differently. Now we’re finding out some of the dangers and concerns, and we want to address them.”

An ordinance passed by the Wichita City Council in June gives the parks department the authority to close parts of the river deemed dangerous based on flow rate and debris in the water.

But that could be difficult to enforce, Houtman said.

“People are still going to go out on the river. They see it as a challenge, something to do … I think everyone within the city wants to prevent these (accidents) from happening.”

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