The Leeds flood warning siren - Everything you need to know
It's the noise which signals that Leeds is at risk of severe flooding.
The city has one flood siren - based at Wyke Beck in east Leeds - and sounds like a traditional Second World War air raid siren. Here's a guide to everything you need to know.
Why is there a siren in Leeds?
Wyke Beck can respond to rainfall very quickly, with flash flooding affecting a large number of properties in less than 45 minutes.
The siren helps the Environment Agency warn large numbers of people all at once. It warns people regardless of whether or not they live in the area or whether they are registered to receive its free flood warning service. And the siren can be sounded quickly after the initial decision to warn is made.
How does the siren work?
Environment Agency river level gauges - located in a green box - on Wyke Beck detect high water level and send an alarm to its on call 24/7 Flood Warning Duty Officer.
Based on the best available information and, where possible, in discussion with local flood wardens, the Flood Warning Duty Officer will sound the siren to provide advance warning of flooding to property from Wyke Beck. The siren complements the Agency's Flood Warning Service, which people sign up to so that they receive flood warnings direct to their phones.
What does it sound like? How loud is it?
The siren sounds like a traditional Second World War air raid siren. It is sounded continuously for two minutes. At short range, it is likely to have noise levels of 120-145 db (similar to an ambulance siren) and it may be heard up to 1,500 metres away, depending on local factors such as levels of traffic, weather conditions.
What should I do if I hear the siren being sounded?
The Environment Agency say the priority should be to keep yourself and your family safe.
A spokesman said: "Move away from fast moving flood water and do not put yourselves at risk by walking or driving through it. Be aware that flood water is likely to be polluted by sewage and other contaminants.
"If your home is likely to be flooded and time allows, install flood protection equipment if available, and move precious items well above ground level. Check on neighbours and offer assistance if safe to do so."
If the siren sounds, does that mean I’m going to flood? How long will it be from the siren sounding to us flooding?
The spokesman added: "!If we sound the siren or issue our flood warning direct to your phone/mobile etc, we are expecting properties to flood in this area. In some cases only one or two properties may flood, while in others many more may flood. By issuing the warning we are trying to give people as much time to get themselves and their families safe, and to take action to protect their property.
"However, we know that this beck can rise extremely quickly and there may be little or no warning. Therefore it is important to plan what you would do and also to consider steps to take now which could ultimately reduce damage/distress caused."