Monday, 20 March 2017

Tramping Skills: River crossing

River crossing skills examined...

In Colonial times drowning was referred to as the New Zealand disease because so many people died trying to cross rivers etc. It is hardly surprising given the number of beaches, lakes, rivers and streams in this country.

Drowning remains a major cause of fatalities amongst kiwi trampers to this day.

Contemplating a crossing of the Otira River, Arthur's Pass NP

Because of our profusion of water you need to be able to assess a body of water and have the skill and experience to pick safe crossing points.

Here are some tips I have learnt over the years about what to look for when you approach a water body and how to decide how, when and where you will cross.

To cross or not to cross?

The most fundamental question you need to ask yourself is Do I need to cross this? This seems obvious yet I'm sure some people have never stopped and thought about why they are crossing a particular body of water. As soon as you enter a river you can potentially find yourself in trouble so asking yourself why you need to cross is important.

Hawdon and where will I cross...?
If there is any possible way to avoid entering a river, stream or lake you should take advantage of it. Is there a bridge nearby you could use, can you reach your location without crossing water or is there an alternate route that avoids water crossings. These are all questions you should ask yourself.

Nice...shallow, slow moving water...can be crossed easily at this point!

Every river crossing is dangerous: regardless of the amount of aids, training and experience you have. Even veterans with 40+ years of experience have been swept away by rivers so never assume you are immune. Take every crossing seriously.

Crossable with care as part of a group (...why...there is a bridge 100 meters up-river!)

Cross these rivers aka swirling vortices of death...don't even think about it!

As the Mountain Safety Council (MSC) say... "If there are any doubts about the safety of crossing, don't cross - it isn't worth the risk"

Approaching a river

Develop your own process for assessing rivers, streams and creeks when you are out tramping. If you have a mindful process you are much more likely to use it every time you arrive at a river or stream.

Is it safe to cross here or should I look for another option?

Always stop and assess any body of water- never jump in without stopping and formulation a plan to get you safely to the other side. I will often stop for a drink or snack at a river crossing point. This means I am rested before attempting to cross and gives me time to really eye up the river I'm thinking of crossing.

Brew up before crossing a river in Victoria Forest Park

Never attempt to cross a river that is swollen, discoloured, where you cannot see the river bed or if there are debris floating in it. These are all signs of a flooding, dangerous river.

A discoloured Alfred River...danger Will Robinson!

If you approach a river and hear a low rumbling do not cross. the water is moving rocks along the stream bed, these can easily injure you.

Look for a safe place to both enter and exit the river. Avoid steep or undercut banks, debris piles and areas with dense vegetation as these will be difficult places to enter and exit. 

Not a safe exit point, too much debris to negotiate
Be careful of marked fords- rivers are changeable beasts and what was once easy going may now be a certain death trap. An example is the ford over the mouth of the Travers River in Nelson Lakes NP. The ford is marked, yet if you follow the marked path you are led straight into a swift waist deep channel.

The Travers River ford- deep channel near far bank!

If you go 30 meters downriver it is only knee deep right across the river. It is always worth the effort to explore alternate crossing point before you commit.

The MSC have more information about assessing possible river crossing points on their website.

Cross as a group or solo?

You can cross a river by yourself or as a group. The MSC do not recommend crossing a river solo. The reason for this is that a single person does not have as much stability as two or more. A group is heavier and has more points of contact with the bed of the water course. Even having two makes your chances of successfully crossing much higher.

Obviously there will be times when you must cross rivers singly but you should do everything in your power to avoid doing so.

Group crossing

If you are part of a group you should cross using the mutual support method.

Using the mutual support method

Follow these rules when using the mutual support method:

  • Choose a crossing leader before entering the water. They control the crossing- all group members listen close for instructions.
  • Choosing a crossing point is a group decision- discuss your options.
  • Strongest person to be at upstream end of group
  • Upstream person slightly forward of next, you want a shallow incline to the group
  • Second strongest person at downstream end of group
  • Hands grasp neighbours pack-straps/clothing around their body
  • Group should be parallel to the flow of water, this will minimise the force of the water
  • Maximum river depth no more than thigh deep. The only exception would be in very slow moving waist deep water. If it is deeper than the thigh DO NOT CROSS regardless of the group size!
  • Take small shuffling steps all the way across the water.
  • The group moves as one unit- all the way across.
  • Move diagonally downstream with the flow of the water. Don't fight the river flow- conserve energy!
  • Pack straps loosened and sternum strap undone
  • Can be used by 2-5 people, if more than 5 then you need a second group
  • Suitable for even and uneven river beds, your neighbours stop you falling into too deep of a hole.
  • Always wear footwear as rivers can be slippery.

Nicely done- group using the mutual support method

Crossing solo

If you must cross solo use the solo supported method. Grab a pole at least your height, use this as an extra leg to give you more stability. Shuffle your way across the river maintaining two points of contact at all times.

Solo supported using a pole...
...and in deeper water!

You should really angle this pole across your body with the upstream end planted on the bed of the river.

Solo supported method, pole anchored on river-bed

Walking poles can be used in ankle to knee deep water but are not long enough for anything over knee depth.

Crossing using trekking poles for support

If you have the option of crossing as a group or solo ALWAYS cross using the group method.

General river crossing technique:

Take care to remember these points when crossing any body of water:

Having decided on your crossing point make sure all gear is secured inside your pack. Loose items on the exterior can be lost or drag you under once waterlogged.

NO! Stow that shite in the pack....

New Zealand's steep terrain and large watersheds mean that rivers can rise and fall quickly. Watch for the first signs of impending floods: discoloration and floating debris. Do not camp to close to riverbanks if there is rain forecast for the watershed you are in, floods of up to 10 meters have been recorded before.

The large and steep catchment area for the Anti Crow River in Arthur's Pass NP

Equally, if a river is too high to cross find shelter and wait. It is highly likely that the water level will be much lower after a couple of hours of fine weather. Comprise a striking haiku as you wait... to my ears
is the rain droplets falling
in the inky night...

Undo any sternum straps and loosen but do not remove your waist belt. Sternum straps are a possible choking hazard as the buoyancy of your pack can force them up towards your neck. The waist belt will help with stability if you fall into the water.

Sternum straps as a choking hazard...

Avoid wearing loose clothing that could gather weight from the water. Remove it and stow it until you reach the other side. I'm thinking about fleece trousers and wet weather pants here.

Always wear your footwear. Rivers can be slippery and they also conceal sharp rocks etc. on their beds. I know you like dry boots but safety comes first.

Wet feet but safely across the river!

Dont skip from stone to stone or walk along logs. You are far more likely to end up in the river doing this and may injure yourself. I have seen numerous people take a full immersion bath just because they wanted to keep their boots dry.

Bad crossing technique: don't do this...

...don't do this...

...and never do this!

Use a plastic pack liner or water proof dry bag to keep your pack contents dry. Make sure you will still have dry warm clothing and a sleeping bag for the end of the day.

Standard MSC pack liner bag

My pack showing my plastic pack liner exposed!

What if I fall mid stream?

Good question. Every tramper is going to experience the buttock clenching shock of going adrift in a river at some time, I certainly have.

In 1998 I was part of an Army group crossing a swollen river in the Kaimaniwa Mountains. Three of us got swept downstream for about half a kilometre. I am not ashamed to say it frightened the be-Jesus out of me as I am not a good swimmer at the best of times. We were lucky and all managed to reach the river banks but not everyone has such luck.

If you do fall use your packs natural buoyancy to keep you afloat. Get onto your back, face downstream and use you arms in a sculling motion to work your way to the river side.

Sculling to safety after a river mishap, photo from MSC website

Once there carefully remove your pack and slowly work both it and yourself up the bank to safety.

If you do not have a waist belt or it is undone use the older MSC advice as it is equally effective:

Pushing straps to stabilise pack

Lean back on your pack and face downstream
Push down on the bottom of your pack straps to keep your pack on your back
Keep your legs in a running position and head diagonally towards the bank
Remove pack only if you lose control of it/or it pushes you under. In that case grasp it to your chest and use it as a pack float instead.

Once you are safely out of the water you need to get dry and warm as quickly as possible. Hypothermia is a real risk after a total immersion on even the warmest, sunny day. If required you should stop, erect some shelter, get into your sleeping bag and get some warm food/drinks into you. If you are part of a group you can also light a fire to warm you and dry out clothing.

Regrouping and drying off after river crossing

For more information on river crossing technique see the MSC website.

Practice makes perfect, but....!

Even with mastery of crossing methods and a lifetime of experience people still have problems from time to time. Learning about rivers and how to cross them really is a lifelong learning experience. Hey, I have been tramping for over 25 years and I am still learning new things every time I cross a river.

Contemplating my 7th crossing of  a very low Waimakiriri River at Klondyke Corner, 2018

The best advice I can give you is to take a NOOA, NOLS or an organised river safety course. These will teach you the basic skills you need to survive in New Zealand rivers. This knowledge will be enhanced with the experience you gain every time you cross another body of water.

Be safe out there!

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