Nepal’s flood early warning system can be tried in flood-prone Indian rivers

Mahender Bahadur Karki and Raj Kumar Mahto enjoy immense respect among the villagers here for being the caretakers of a community-based flood warning system that can be successfully replicated along the banks of Bihar's 'river of sorrow', the Kosi.

"We would be happy to install the Community Based Flood Early Warning System (CB-FEWS) on a trial basis in the Kosi basin in Bihar. We will do it free of cost and sponsor all the necessary tools and instruments," said Shahriar Wahid of the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD) that has evolved the system.

When water levels rise, a sensor located in an upstream section of a flood-prone river, alerts the system's local caretaker and residents can move to safety (Photo: IANS - for representational purpose only)

Neera Shreshtha Pradhan, a water and adaptation specialist at ICIMOD explained how the system works.

Its mechanics begin with a sensor rod that is calibrated in consultation with the local communities to the specific conditions of the landscape and river and installed in an upstream section of a flood-prone river. 

When water levels begin to rise during the monsoon, the sensor sends a message in the form of a light and a loud buzzing noise to a receiver located at the nearby house of a resident who has volunteered to be the system's local caretaker.

"When the water is rising to dangerous levels, the caretaker calls or sends a text message to the numbers on a contact list of individuals downstream as well as the adjacent community and government institutions to inform them of the potential flood," said Pradhan.

The system is easy to understand and use, said Raj Kumar, who attended a training session in Kathmandu last year along with participants from Afghanistan, India and Nepal.

"Earlier, we never used to know for sure how high the water was, but now there hopefully won't be problems. This will be good for our villages," he said.

Sagar Bajracharya, a hydrological analyst at ICIMOD, said the instruments required for the system cost only $1,200 (Nepali Rs.128,000/Indian Rs.80,000), including the receiver station and transmitter.

The Kosi Basin Programme of ICIMOD, together with the Department of Hydrology and Meteorology's Community-Based Flood and Glacial Lake Outburst Risk Reduction Project, is currently piloting United Nations Development Programme-supported community-based flood early warning systems along Nepal's Ratu Khola (rivulet) in an effort to give flood-prone communities the extra time that they need prior to a flash flood.

On June 30 last year, when heavy rains caused water levels in the Ratu Khola to rise, the system successfully transmitted warning messages to the receivers and these were relayed to downstream caretakers. Countless lives were thus saved and loss to property averted.

But the system will be field-tested for at least two flood events to ensure its efficacy and accuracy.

Unlike earlier, villagers in the flood-prone Terai region of the Kosi basin in Nepal are now hopeful of getting real-time information to reduce the impact of flash floods.

"Our hope now lies with Karki to alert us in advance and provide enough time to save lives and properties," said Sumitra, a resident of Lalgadh village.

Karki, a young resident of the same village near Ratu Khola in Mahottari district in south-eastern Nepal, is in-charge of the CB-FEWS that was installed along the river before the last monsoon.

Dinesh Kumar Shah and Mohan Mahto of Sarpallo village said CB-FEWS is a new ray of hope for around 15,000 people living here to get enough time to evacuate, if necessary. "We have been facing yearly flash floods and are keen to get help of the system."

Logically, if the system has worked in Nepal, so should it in India.

Wahid, programme coordinator of ICIMOD's Kosi Basin Programme, said it is for the Bihar government to invite them to install two or three of CB-FEWS before this year's monsoon. "If it works successfully, the Bihar government can take care of them next year and install more systems."

(The writer's visit was at the invitation of ICIMOD.) - IANS