Most pages in this app tell you how to do something. This one is mostly about deciding not to, because river and flood crossings are one of the small number of situations where the correct answer is nearly always to turn round, and where people die doing the thing that felt reasonable at the time.
The scenario cards and flood-proofing both say the same thing and it is worth repeating here: go up early rather than out late, and never walk or drive through moving water.
Start from no
Walking an extra hour is not the emergency. Cold, tiredness and the wish to be finished are what make crossing feel reasonable, and they are exactly the factors that make it dangerous.
Waiting works. Upland streams that rise in twenty minutes often fall again in a few hours. Shelter, get warm, eat, and look again.
Why moving water wins
Reading the water
If you are assessing a crossing at all, these are the things that matter.
- Speed. Throw a stick in. If it moves faster than you can comfortably walk on the bank, that is too fast.
- Depth. Above the knee in any current is out. Below the knee in fast water can still be out.
- The bed. Rounded boulders are the worst footing there is. Gravel and sand are best.
- Width. A wide shallow braided section is a far better prospect than a narrow deep one, even though the narrow one looks quicker.
- Where to cross. Wide, straight, shallow sections with a gentle gradient. Avoid the outside of a bend, which is deeper and faster and where the bank is undercut.
- Downstream. Look before you step. A pool with a clear runout is survivable; a fall, a weir, a culvert or a strainer of fallen branches is not.
- Rising or falling. Put a stick at the water's edge and watch it. Debris and discoloured water mean rising.
A strainer is the specific killer: fallen trees or branches that let water through and hold a body against them. Never attempt a crossing upstream of one.
Floodwater in a street
Different hazards from a river and, in some ways, worse.
Vehicles
If you genuinely have to cross
Reserved for a shallow, slow stream that you have assessed and where turning back is genuinely worse. If you are reading this to justify a crossing you already doubt, that is the answer.
- Undo the rucksack waist belt and chest strap. The pack must come off instantly if you go in. This is the single most important preparation and it is the one people forget.
- Boots on. Bare feet on a rocky bed guarantee a slip and an injury. Wet boots are a nuisance; a broken ankle in a river is not.
- Trousers on, waterproofs off. Waterproof trousers trap water and act like a sail.
- Face upstream and sidestep across, leaning slightly into the flow.
- Use a pole or a stick as a third point of contact, planted upstream, and move only one point at a time.
- Cross at an angle downstream, working with the current rather than fighting straight across it.
- In a group, link arms in a line facing upstream, strongest at the upstream end, and move together as one unit. Do not hold hands, which lets go.
- One at a time if you have a rope, with the rope belayed from the bank and never tied round anybody.
Never tie yourself to a rope in moving water. A person on a fixed line in a current is held under by the flow. Ropes are for support and for retrieval, never for attachment.
If somebody goes in
Afterwards
- Everything wet comes off. Wet clothing takes heat out many times faster than dry, and this is the fastest route into hypothermia there is.
- Dry, insulate, and get moving or get sheltered. Sugar and something hot if they can swallow safely.
- Treat contact with floodwater as contamination. Wash hands thoroughly, cover any cut, and see wound care for anything broken. Watch for illness in the following days and mention the water to a clinician.
- Dry boots slowly, never on a heat source. See boots and shoes.
- Reconsider the plan. A crossing that went badly is information about the rest of the route.