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The Killers In Our Rivers

In the summer, we see the headlines: “18-year Old Identified as Drowning Victim”, “Search Continues for Missing Kayaker” or “Two Men Drown While Fishing on Sunday”.  In the past, I would pass over the headlines without reading the article and think, “That’s sad, someone must not have been wearing their life jacket.”  Over time however, I have learned that a life jacket is not always enough.  I have started reading below the headlines and found many of those who drown in our rivers were not doing anything different from the rest of us.  They were out fishing with friends or taking a refreshing dip on a hot summer night or kayaking down a river on a beautiful spring day.  Sometimes, those who drown are the best among us, heroes who jump in the water to try to save a stranger.

As I have dug deeper, I have found many of these drownings are not happening on isolated, random locations along our rivers.  Often there is a man-made hydraulic structure involved.  An abandoned low head dam, a small sheet pile wall constructed across the stream to stop erosion, or large steel gates that are being used to control the flow of water.  During certain times of the year, if the flow conditions are just right (or actually wrong), these structures can change a slow meandering stream into a drowning machine.  The two most common killers in our rivers in Nebraska can be classified into two categories: hydraulic rollers and strainers.  In Nebraska, 2019 was a particularly bad year with at least four drownings occurring at hydraulic structures in our rivers.

Hydraulic Rollers

A 2016 PBS documentary entitled, Over, Under, Gone: The Killer in Our Rivers, provides an excellent introduction to the dangers associated with hydraulic rollers. Hydraulic rollers develop anywhere large quantities of water go over a vertical drop into a pool of water.  Any vertical wall spanning from one side of a river to the other, like a low head dam, can create a hydraulic roller.   What’s surprising, a drop as small as six inches under certain flow conditions can create this deadly roller effect while the surface of the water can appear calm, hiding the submerged dangers below. 

Once a victim is trapped in the roller, it can be very difficult to get out, regardless of whether or not the victim is wearing a life jacket.   Powerful, recirculating currents force anything caught in the roller down to the bottom of the stream and then release it back up to the surface only to plunge it back down again.  Due to the way the water churns and aerates in the roller, air bubbles decrease the buoyancy of the water making it difficult to stay afloat, even if you are wearing a life jacket.  The best way to try to escape a roller is to perform the dangerous maneuver of removing your life jacket and swimming out the bottom of the roller along the riverbed.

Figure Courtesy of ASDSO.

Strainers

A strainer is anything in a river that allows water to flow through but will trap a kayaker or a swimmer.  Small pipes, open cracks or joints in concrete, partially open gates, or even a fallen tree can act as a strainer in a river.  Similar to a kitchen strainer used to drain spaghetti or wash vegetables, a strainer in a river allows water to pass while holding on to everything else. People can become pinned against the face of a structure by the force of suction created by water flowing through holes and cracks.  Structures such as spillways and bridge piers can catch logs, sticks and debris and form large strainers.  Always be alert to the possibility of fallen trees and debris and do not swim close to dams or other hydraulic structures.

Know the Risk and Be Aware of Your Surroundings

Most of these structures are not well marked and there are no signs warning of the dangers.  Therefore, before going out on a tube or kayak, plan your trip.  Scan aerial photos along the route, looking for potential hazards.  Avoid fallen trees.  Talk to someone who has made the trip before.  Get on the Nebraska Canoe and Kayak Public Facebook Page and ask for advice; or visit the Nebraska Game and Parks Commission’s website and see their Water Trails Guide for well-traveled canoe routes. Give friends a trip itinerary and let them know when you expect to be home.   If you see a hydraulic structure ahead, get out and portage around it.  The thrill of going over or through the structure is not worth the risk.  Concrete walls encroaching from the banks of a river are a sign there may be trouble ahead. Watch and share the 30-minute, online PBS documentary Over, Under, Gone: The Killer in Our Rivers.  

If you are swimming in a river, do not go near dams, spillways, bridges or culverts, even if there are no signs warning of the potential danger.  Always wear a life jacket.  Rivers are constantly changing.  A swimming hole next to a low head dam that was completely docile yesterday could be a drowning machine today, even with a life jacket.  Sand bars are temporary.  They can evaporate and disappear in an instant, plunging you or your loved ones into the water. If you are near a hydraulic structure, even if you are a good swimmer, you may become trapped in the current.  Educate your kids and grandkids of the dangers.

Make It Home Safe

Some of my favorite memories growing up in Nebraska are from swimming off a sand bar on the Niobrara River, fishing along the Elkhorn River, or going for a boat ride on the Missouri River.   Let’s continue to take advantage of our rivers and lakes in Nebraska in 2020, but let’s make sure we know the risks and make it home safe.

Aerial view of the low head dam on the Big Blue River under the Court Street Bridge in Beatrice. (Google Image)

Dangerous low head dam in the Big Blue River under the Court Street Bridge in Beatrice.

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