Downed Power Lines — How to Stay Safe

Downed power lines are one of the most immediately lethal hazards following storms, vehicle accidents, infrastructure events, and construction incidents. A line on the ground may still be energised at distribution voltage (typically 11,000 volts in the UK, up to 33,000V at higher distribution levels) or at lower 240V supply voltage. Both are potentially fatal on contact.

The danger is significantly greater than most people appreciate. Current from a downed line can pass through the ground for several metres around the contact point — a phenomenon called "step potential" — meaning you can be electrocuted without touching the line itself.

Why Downed Lines Are So Dangerous

Hazard	Explanation
High voltage	Distribution lines carry thousands of volts — contact at this voltage is uniformly fatal
Energised appearance	A downed line may look dead and still be carrying full voltage
Ground voltage gradient (step potential)	Current flows outward from the contact point through the ground; entering this zone completes the circuit through your body
Arcing and flash	If you approach, the current can arc across air to reach you — you do not need to touch the line
Secondary hazards	Lines on vehicles, on fences, on water — the hazard transfers to any conductive object connected to the line
Intermittent energisation	Lines connected to automatic reclosers (common on UK distribution networks) can be de-energised then automatically re-energised without warning

⚠️ Never assume a downed power line is safe because it is not sparking or because you can see no visible activity. Lines can be energised while appearing completely dormant. The only safe assumption is that every downed line is live until confirmed otherwise by the network operator.

Safe Distance

Scenario	Minimum Safe Distance
Low-voltage line (240V, service drop)	At least 8 metres (25 feet)
Medium-voltage distribution line (11kV)	At least 10 metres (33 feet)
High-voltage transmission line	At least 30 metres (100 feet); call emergency services immediately
Line on water (puddle, stream, flooded area)	Do not approach; water conducts electricity over wide areas
Line on metal fence or structure	Do not approach the fence or structure

When in doubt, stay further. The step potential zone around a downed distribution line can extend several metres in dry conditions and significantly further in wet conditions.

What to Do When You Encounter a Downed Line

On Foot

1. Stop immediately when you see or suspect a downed line.
2. Do not approach — maintain minimum distances above.
3. Warn others — shout to keep other pedestrians and vehicles back.
4. Do not touch anything connected — fences, vehicles, puddles, anything that could be in contact with the line.
5. Call 999 and your network operator (UK: call 105, the power emergencies number).
6. Stay to direct emergency services if safe to do so — at a safe distance, visible to incoming emergency vehicles.

If you are already in the step potential zone (you feel a tingling in your legs):

• Do not run — running increases the voltage gradient you expose yourself to with each stride
• Shuffle with feet together (or hop on one foot) away from the line — minimise the distance between your feet at any one time; this reduces the step potential voltage difference
• Move in a straight line away from the line contact point

In a Vehicle

If your vehicle hits a power line or a line falls on your vehicle:

Stay inside the vehicle. This is the critical rule.

Situation	Action
Vehicle in contact with line	Stay inside; the vehicle body protects you; touching anything outside completes the circuit
Engine still running	The car may still be driveable; if the line is clear of tyres and path, drive forward until clear of the line
Vehicle not driveable	Remain inside; call 999; wait for network operator to de-energise the line
Fire in the vehicle	This is the only scenario where exiting may be necessary

If you must exit a vehicle in contact with a power line due to fire:

1. Open the door as wide as possible.
2. Do not step out — jump. Both feet must land simultaneously, and you must not touch the vehicle with any part of your body when your feet hit the ground.
3. Shuffle away with feet together, not walking normally — step potential applies to the ground around the vehicle.

Why stay inside: Your vehicle's rubber tyres provide insulation. The moment you step from the vehicle, you become a path for current from the vehicle's body to ground. A person who climbs out of a car in contact with a power line and stands on one leg with a hand on the car has created a circuit.

Downed Lines and Flooding

Flooding around downed or damaged power lines is particularly dangerous:

• Water dramatically extends the area of electrified ground around a downed line
• Floodwater can carry current from downed lines for distances of 50 metres or more
• Do not wade into floodwater near or downstream of visible power infrastructure
• Call 999 and the network operator (105 in the UK)

After a Storm — Checking Your Property

After severe weather, check for infrastructure damage before approaching:

Area	Check
Service cable to house	Has the overhead cable from the street snapped or is it hanging low?
Garden fencing	Does it contact any overhead cables?
Trees near the boundary	Has a fallen tree brought down cables?
External electrical fittings	Are outdoor sockets, security lights, or satellite dishes damaged?

If your service cable is damaged, call your network operator before entering the building — a damaged service cable can energise the building's metalwork.

Who to Call in the UK

Situation	Number
Downed line on road or public area	999 (emergency) + 105 (power network)
Power outage without visible damage	105
Line touching your property	105; evacuate if it contacts the building
Damaged electrical meter or service cable	Your energy supplier + 105

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Quick Reference

Situation	Action
Downed line on ground	Stay 10m away minimum; call 999 and 105
Tingling in feet near line	Shuffle away with feet together; do not run
Line on your vehicle	Stay inside; call 999
Must exit vehicle with line contact	Jump clear; both feet simultaneously; shuffle away
Line on flood water	Do not enter water; stay back 50m; call 999
Assume any downed line	Live until confirmed de-energised by network operator