What to do in the 24 hours before a river flood

When the forecast office publishes a crest with a time attached, a countdown begins with one enormous advantage over almost any other disaster: you know how long you have. What follows is a work order designed so that when the time runs out, the things that matter are already handled.

T–24 h · Confirm and decide

The first job is not moving anything: it is knowing what to expect.

• Write down the forecast crest and its time. Everything else hangs on those two numbers.
• Compare it against your elevation. If you do not know it, this is the moment to check the flood map.
• Decide whether you leave or stay, and tell someone outside the area. That decision is easier now than in twelve hours.
• Fill the fuel tank. Stations run out of both fuel and power.

T–18 h · The irreplaceable

• Documents, deeds, policies, passports → dry bag, and upstairs.
• Medication, prescriptions and medical equipment.
• Hard drives, backups, family photographs.
• Photograph every room with appliances visible before you start moving anything.

T–12 h · What is saved by moving it

• Vehicles to confirmed high ground. Not the corner: somewhere you know sits above the forecast level.
• Electronics, small appliances and anything on the ground floor.
• Unplug and lift what you can; what you cannot, raise onto tall furniture.
• Chemicals, fuel and paint go up. If water reaches them, it contaminates the whole house.

T–6 h · Close the house

• Shut off power and gas if you can reach the panel on a dry floor.
• Close backflow valves if you have them, to reduce sewage return.
• Fill bathtubs and containers with drinking water.
• Place sandbags at doorways if you have them, knowing what they are: help, not a barrier.

T–0 · Leave

• Use the agreed route, and if it is cut, the agreed alternative rather than an improvised one.
• Do not cross moving water, on foot or in a vehicle. Six inches knocks an adult down; twelve floats a car.
• Tell your out-of-area contact that you are leaving and where you are going.
• Take the bag, the documents and the medication. Everything else is already where it needs to be.

Afterwards

Do not go back until it is cleared. When you do: no light switches until the wiring has been inspected, gloves and boots because the water is contaminated, and photographs of all damage before throwing anything away.

The ZonaProtec monitor shows the forecast flow of nearby rivers against their own recent history, plus official warnings in effect at the point you search.