River crossings are where confident walkers get into trouble

The points below about crossing rivers on foot are ordered by how much difference they make, not by how often they get repeated.

Speed matters more than depth

The force of moving water increases with the square of its velocity, so fast shallow water can be more dangerous than slow deep water. Knee-deep water moving quickly can lift a person off their feet. Judging a crossing on depth alone is the most common misjudgement.

Speed is easy to underestimate by eye and easy to check by dropping a stick in and walking alongside it, and water travelling faster than a comfortable walking pace is already carrying more force than most people expect.

Look for the wrong-looking place

The narrowest point is usually the deepest and fastest, because the same volume is passing through less space. A wide, braided, shallow section is generally safer even though it looks less convenient.

Crossing above a hazard — a fall, rapids, a strainer — rather than below one is a basic and frequently ignored rule. On a bend the outside is deep, fast and often undercut while the inside carries the shingle, so a crossing placed just above the inside of a bend uses about the shallowest ground the river has to offer.

Technique reduces the risk

Facing upstream, moving sideways, and using poles or a stick for a third point of contact all improve stability. Unbuckling the hip belt and chest strap means the pack can be shed if you go in, which matters more than anything else you do. Groups can cross linked, with the strongest upstream, though this needs practice to be safer rather than more dangerous.

Otherwise only one person should be committed at a time, because a crossing where the whole party is mid-stream at once leaves nobody standing on the bank able to help whoever goes in.

Conditions change fast

Rain in the catchment raises a river hours later and often without rain where you are standing. Snowmelt rivers rise through the afternoon and are lowest in the early morning, which is a planning fact rather than a curiosity. A crossing that was fine on the way out may not be on the way back.

The direction of change is readable from the bank: wet stones and a dark band above the current waterline mean the level is dropping, while floating vegetation, water colouring up and a rising noise from upstream mean it is not.

The decision is on the bank

Once you are committed mid-stream the options narrow sharply, so the judgement has to be made before entering. Waiting a few hours, walking upstream to a bridge or turning back are all ordinary outcomes.

Most serious incidents involve a party that felt committed to a schedule. The decision is far easier if it was made at home, so any route with a serious crossing should arrive carrying an answer to the question of what happens when it is up: a named alternative, a bridge upstream, or the spare day and the food to sit it out.

The exception is usually weather, which overrides most planning.

If you do go in

The immediate danger in fast water is foot entrapment: standing up in a current wedges a foot between rocks and the flow pushes the body under. The taught response is to get onto your back with feet downstream and near the surface, use your arms to ferry across the current at an angle, and stand only once the water is slow and shallow. A pack with air trapped in it floats and can be held in front as buoyancy, which is one more reason the hip belt should already be undone before you step in.

Locally, this is a perishable skill rather than a fact, and any group crossing rivers regularly gets far more from a swiftwater safety course run by qualified instructors than from anything written down.

Everything above, in order of what to do first

1. Speed matters more than depth. The force of moving water increases with the square of its velocity, so fast shallow water can be more dangerous than slow deep water.
2. Look for the wrong-looking place. The narrowest point is usually the deepest and fastest, because the same volume is passing through less space.
3. Technique reduces the risk. Facing upstream, moving sideways, and using poles or a stick for a third point of contact all improve stability.
4. Conditions change fast. Rain in the catchment raises a river hours later and often without rain where you are standing.
5. The decision is on the bank. Once you are committed mid-stream the options narrow sharply, so the judgement has to be made before entering.
6. If you do go in. The immediate danger in fast water is foot entrapment: standing up in a current wedges a foot between rocks and the flow pushes the body under.

The takeaway

Judge it from the bank, unbuckle the pack, and accept that turning back is an ordinary day.

The route rewards patience more than equipment.