Eight flood warning sirens will be sounded this morning across the Upper Calder Valley as part of a live training exercise 'Operation Calderdale17'.
They will be put to the test in Walsden, Todmorden, Hebden Bridge and Mytholmroyd to help make sure communities are as prepared as possible for any risk of flooding this winter.
The Environment Agency uses the sirens, which have an audibility level similar to that used by emergency vehicles, to warn people rivers are expected to flood.
They will be tested together at 10.45am, before the second major training exercise of its kind is held in the area to test the emergency response of the Council, emergency services and partner organisations to a major flooding incident, including a live search and rescue operation.
Each siren test will last for two minutes. Residents and businesses in the towns do not need to take any action when hearing the sirens at these times. Loud hailer vehicles will be used to alert people to the tests, ahead of the sirens being sounded.
There are four sirens in Todmorden which are sited at the fire station, the high school, Morrisons and Warmans. There is also one at Walsden, two in Hebden Bridge, one in Mytholmroyd and a community siren in Sowerby Bridge.