The system in place has a number of Whatsapp groups, where Bhutanese citizens living close to the border send alerts to Indians to give an early flood warning. The messages are along the lines of, “Please caution your communities who are vulnerable to swollen river disaster. There is heavy flooding all over Gelephu and her peripherals.” 

Usually, we are the ones to ignore WhatsApp messages. 
But these forwards have actually come to the rescue of villagers along the Bhutan-Assam border. A system of important flood-alerts from their friends living across the border, is helping save thousands of lives in Assam.

Indian Express

This system came into place after the Bhutan-India Friendship Association (BIFA) teamed up with North East Research and Social Work Networking (NERSWN), an Indian NGO. 

NERSWN executive director Raju Narzary told Times Of India about how the system works, 

Our members constantly monitor WhatsApp. The moment we get any alert, we send it to the last villager. We have already told every border villages what to do when we send an alert. We have taught them the basics: how to take their cattle to higher ground, stock up on food and water and carry enough clothes. 

The messages are both textual and audio-visual. This type of a heads-up warning can become a life-saver for villagers in Assam, as they can prepare for emergency situations beforehand.