 The flood was probably caused by offshore vortices along the west coast and perturbations higher up in the troposphere and is not attributed to any depression or cyclonic disturbance in the Arabian sea or the bay of Bengal.The rivers in the state were in spate and a sudden opening of the Mullaperiyar sluices caused even greater misery.The restriction in flow due to swelling of the Periyar river, blockages formed by debris, changes in the river flow and other related reasons caused flooding even in places like Munnar which is 1500m above sea level.