Source: Department of Conservation
By Lucy Holyoake
Evaluating if a river is safe to cross, and knowing the best way to do so is a vital skill for trampers in the backcountry.
Here are some of the lessons I learned at a river safety course, and why I think you should do one too.
I’ve heard a lot of stories of river crossings gone wrong, but this one stuck with me.
A couple I met at the river safety course told me about a recent overnight tramp they did with a group of friends. They were all quite new to tramping and had just started doing overnight trips. They’d picked a relatively easy track, with one small unbridged stream close to the car park.
On the way in the stream was about ankle deep, clear and slow moving. They all crossed it without issue.
But overnight, it rained. A lot.
The rain continued to pour the next morning, but everyone was itching to get home and dry, so they packed up and headed back down the track.
The stream was unrecognisable.
It was in flood: the dirty water was swollen and surging, waist-deep in places with tree branches were being swept rapidly down-stream.
The group knew the car was close. It was Sunday, they needed to get back for work the next day. Only this flooded stream stood in their way.
So: they crossed it anyway. And very nearly didn’t make it home.
Wading through the thundering dirty water, each step forward nearly toppled them into the river and swept them away.
They were very lucky not to have drowned that day.
The experience shook them. Which is how we came to be on the same river safety course.
Lesson #1: Don’t
Right off the bat, the course instructors hammered this point: you never have to cross an unsafe river.
It may sound too simple but it’s some solid advice.
The couple made the decision to cross the flooded river because they felt it was their only option. They were on the last day of their trip, soaked and tired, just wanting to get home. They disregarded the danger and chose to go in anyway.
They were lucky. One misstep, one loss of balance in the surging water and they could have been killed.
Many of the course instructors were search and rescue volunteers. They all had stories of trampers, both experienced and new, underestimating the danger of crossing an unsafe river. Horror stories where if they just hadn’t got in the water, if they’d waited for the water level to drop, if they’d only crossed at the bridge instead, they would still be alive.
Lesson one sunk in for all of us. If a river is unsafe, do not attempt to cross it.
It’s not worth your life.
Lesson #2: Preparation is crucial
The instructors were clear that the first method for avoiding unsafe river crossings is to do your research before you head out.
During your planning, make sure you:
- Choose a track that is suitable for every tramper’s skill and experience. If there are members of your party that are not comfortable with river crossings, choose a different track.
- Identify any river crossings on your intended route, as well as alternate track options if the river is unsafe. Choose routes with bridged crossings where possible.
- Always check the weather before you go. Be prepared to choose a different track without river crossings if the weather forecast predicts heavy or prolonged rain.
- Have a plan if you need to wait for a flooded river to drop. Take extra food, warm clothes and emergency shelter in case you need to wait a few extra days. Consider taking a satellite communication device so you can tell someone you will be late out.
Doing this prep beforehand sets you up to make safe, informed decisions around rivers while you’re out there.
Lesson #3: What to do instead of crossing an unsafe river
Sometimes, no matter how well we prepare, things can go wrong. If you find yourself standing in front of a river that isn’t safe to cross, what do you do instead?
Option 1: Wait it out.
River levels can drop as quickly as they rise. Sometimes that can mean that if you wait a few hours, a swollen river can become safe to cross.
But it could also take days for the water level to drop, depending on the weather or snow melt conditions. This is where your extra food, clothes and shelter come in. Once the river levels have dropped, crossing may be possible again.
Option 2: Use your ‘Plan B’
Check your map for your chosen alternative routes without river crossings and take those instead. Sometimes there may be a bridge further along the river, so always check your map for these!
Option 3: Return the way you came
If you can get home safely by turning around and returning the way you came, do it.
Option 4: Call for help
If options 1-3 fail, call for help. It’s safer than attempting a potentially fatal river crossing. Always take a distress beacon with you, just in case.
Lesson #3: The warning signs of an unsafe river
You might be wondering, what exactly is an unsafe river?
The instructors broke down the key things to look for when assessing whether a river is unsafe.
Some rivers are naturally deep and fast flowing, even without being in flood. These can be unsafe to cross at any time. Flooded rivers are very dangerous to cross.
Here’s how to spot an unsafe river:
- The sound of rolling rocks on the riverbed
- Dirty, discoloured and/or cloudy surging water
- Visible debris in the river such as tree branches
- Water moving faster than normal walking speed
If these features are present, the river should not be crossed.
Sometimes only one of these features may be present. For example, if a river is flowing faster than walking speed but is only ankle deep and there are no nearby debris up or down stream, crossing may be possible.
You should always look for the features of an unsafe river and assess them against the crossing location, considering any upstream and downstream hazards that could make your crossing dangerous.
Even if deemed a safe river, crossing can still be risky – the place you chose to cross is vital.
Lesson #4: Crossing a river involves careful assessment
We broke into small groups to learn how to identify a safe place to cross. The instructors told us that no matter the river, always stop to discuss and assess as a group.
We learnt to look for a spot that has:
- Water depth below thigh deep on the shortest person
- Water speed no faster than walking pace
- Accessible entry and exit points (steep banks can be a hazard and may prevent safe entry/exit)
- No white water or rapids (turbulent, frothy water)
- Flat riverbed surface with minimal obstacles like large rocks
- Runout with minimal hazards (where the river will lead you if you are swept downstream)
Not only are you selecting the safest place to cross, but you’re also choosing your emergency path down the river, if you do get swept down. This is why it’s vital to identify the risks downstream as well as where you plan to cross. It’s all about minimising the risk if you do get swept down.
I was particularly horrified by the concept of getting caught by a strainer – which is when an object like a tree branch lets water flow through but can trap other objects underwater (like people…) with the power of the current keeping them stuck.
Being a strong swimmer is not a guarantee against drowning if you are swept down a river. There are so many hazards present in rivers that could cause even the strongest swimmers to drown – which is why choosing the right spot is so important.
Lesson #5: The mutual support method is the safest way to cross
If you do cross: how do you do it safely? That was what my group and I were all here to learn.
After a morning of learning theory, we got to practice crossing a river as a group.
Wading in by myself first, the water flow was surprisingly strong. It was easy to see how you could lose your footing. Especially if you were on your own in the water.
Lining up in our group of three, we practiced the mutual support method, which is designed to give you extra stability and safeguard against anyone losing their footing and being swept.
As a group we waded into the water wearing our boots, clothes and packs. The strongest of the group were at the upstream end, with the less confident members in the middle.
Our chest straps were left undone and our waist belts were secured but loosened. We wove our hands between our neighbours back and their pack, grabbing on tightly to the top of their pants on their other side.
Keeping our bodies side on to the current, we crossed the river in slow, small steps, moving in a diagonal line downstream so we weren’t fighting against the current.
In moments when peoples’ footing became unstable, the strength of the rest of the group kept them upright and they were able to regain their footing.
It was incredible just how much safer using this method felt, compared to standing in the river alone.
Lesson #6: You really don’t want to be swept down a river
At the end of the course, we got to experience what it’s like to be swept down a river (with careful precautions in place).
In mutual support formation, three of us waded into a section of the river that was deliberately too deep in the centre. We walked along the riverbed until our feet couldn’t touch the bottom.
Then the water swept us off our feet.
Feeling ourselves begin to float was honestly terrifying. I felt an immediate loss of control and had to fight the rising feeling of panic. We’d waded into a safe spot and the instructors were on hand with floatation rings on ropes, so my brain knew I was safe. But my body didn’t quite get the message.
Putting theory into practice, we didn’t let go of each other, staying with our arms linked. We lifted our legs up in front of us, leaning back against our packs. While we don’t take life jackets on tramps into the backcountry, our packs are the next best thing, full of pockets of air in between your gear.
The people on either end used their free arms to try and steer us to shore. And it wasn’t easy! On our first attempt, we couldn’t get out on our own and the instructors had to throw in the rope for us to grab. But they let us feel the fear first!
Please don’t underestimate the danger of being swept down a river! One trapped boot, one boulder to the head or one unavoidable waterfall is all it could take to cause a drowning.
Final lesson: If in doubt, stay out
If you take anything away from this blog, let it be that. If you have any doubts about whether a river is safe to cross, or whether you have the skills and experience to cross safely, stay out of the water.
Doing the river safety training was one of the most helpful outdoor trainings I’ve done as a tramper. Knowing how to identify if a river is unsafe gives me the confidence to make hard decisions when I’m outdoors. And honestly, learning about all the ways a river could drown me was quite the reality check!
If you like to spend your time in the backcountry, please consider doing some formal training. It could save your life.
The Mountain Safety Council’s website is a great place to start learning the skills you need to be safe around rivers in the backcountry.
They have instructional videos, online learning tools and safety manuals to help you level up your knowledge and skills. Check them out at https://www.mountainsafety.org.nz/learn/skills/river-safety
There are numerous river safety courses you can do around the country – you can find one near you through the Mountain Safety Council’s training webpage.
