SV31 - Supervision During Thunderstorms (Lightning)
| Issue Date | Effective Date | Version |
|---|---|---|
| 20/01/2018 | 01/09/2019 | 3.0 |
Purpose
To provide guidance on safe practice for the supervision of outdoor swimming pools during thunderstorms and lightning conditions.
Description
The presence of lightning around an outdoor swimming pool is a safety risk. There are a number of factors that need to be considered, such as the surrounding environment and structures.
Note: A “flash-to-bang” measurement of approximately 30 seconds indicates that the lightning is 10km away. A measurement of 30 seconds or less requires that immediate action be taken.
Outdoor Swimming Pools
An outdoor swimming pool with spacious grounds, may pose a greater risk in lightning conditions. If there are structures such as diving towers, precautions should be taken. For example, the erection of a lightning conductor, higher than the dive tower, would reduce the likelihood of a lightning strike hitting the dive towers.
Evacuation
The closure of the swimming pool should be undertaken when lightning is within 10km of the facility.
Use the "flash-to-bang" method, by measuring the time between a lightning flash and the thunderclap, to estimate the distance away of the thunderstorm.
When lightning is less than 10km away, people occupying the pool and pool surrounds should be evacuated to a covered area, which provides sufficient electrical earthing for a lightning strike. Gazebos, marquees and trees are not sufficient protection from lightning strikes.
Resuming Pool Activities
According to the National Lightning Safety Institute more lightning originates from the back edge of a thundercloud than from the front side, making recreation activity resumption decisions difficult. Managing the risk of lightning strikes, therefore, requires a cautious and conservative approach.
Once lightning has moved greater than 10km away or has subsided, people may return to normal activity. As a general rule, pool activities should remain suspended until thirty minutes after the last thunderclap is heard.
Staff should continue to monitor the weather for changes as storm activity could return.
Electrical Equipment
Electrical equipment should not be used during electrical storms.
The use of portable, battery-powered PA systems (e.g. loud hailer) may be considered when the storm is very close, since fixed-installation PA systems may be struck by lightning.
Telephones should not be used during electrical storms.
First Aid
Anyone struck by lightning should be rescued as soon as it is safe to do so.
The safety of the rescuers should be considered.
The casualty should be moved to a covered area, assessed and treated.
Monitoring
If there are area weather warnings issued, they should be monitored by radio or telephone, if and when safe to do so.
Detailed monitoring is available through the Bureau of Meteorology in each State and Territory.
References / Further Information
- AS/NZS 1768 (Int) 2003 Lightning Protection
- Kithil, Richard. Lightning and Aquatic Safety: A Cautionary Perspective for Indoor Pools. National Lightning Safety Institute. Cited 24/2/2004 at http://www.lightningsafety.com/nlsi_pls/indoor_pools.html
- Standards Journal 2, 2004, Lifesaving Society, Toronto
- www.bom.gov.au/info/thunder/#protection
Previous Versions
- Guideline SU25 Supervision During Thunderstorms, Issue 2, Nov 2005
- Guideline SU22 Supervision During Thunderstorms, Issue 1, Sep 1999
