Increasing salinity, dipping groundwater level hurting Sundarbans
Today in New Delhi, India
Feb 22, 2019-Friday
New Delhi
  • Humidity
  • Wind

Increasing salinity, dipping groundwater level hurting Sundarbans

Rising salinity after Aila and random tapping of potable groundwater for high-yield paddy is pushing the Sundarbans islands towards a new crisis.

india Updated: Mar 22, 2018 17:23 IST
Tanmay Chatterjee
Tanmay Chatterjee
Hindustan Times, Kolkata
Sunderbans,West Bengal,Paddy fields
The Sundarbans, famous for the world’s largest mangrove forest and as the home to the Royal Bengal Tiger, is a unique biosphere comprising more than 100 islands spread across India and Bangladesh.(Samir Jana/HT File Photo)

Sriram Mondal, a farmer at Chhoto Mollakhali village in the Sundarbans, will have to survive on his savings till the next crop season unless there is a normal monsoon this year.

Mondol is facing the crisis after the water table beneath his farmland dried up. And, he admits that he is to blame.

“I made a blunder by tapping groundwater to grow high-yield paddy all these years. In the process, I also killed the only source of drinking water at this spot,” Mondal laments.

The Sundarbans, famous for the world’s largest mangrove forest and as the home to the Royal Bengal Tiger, is a unique biosphere comprising more than 100 islands spread across India and Bangladesh.

The entire region was devastated by Cyclone Aila in 2009. The cyclone brought with it giant waves from the Bay of Bengal that submerged the islands in sea water, leaving thousands of acres unfit for traditional rainwater farming.

To save the locals, scientists and NGOs painstakingly retrieved pre-Green Revolution era paddy seeds that germinate in brackish water.

The experiment ensured food security for the local population but not profit for farmers. So, in the years that followed, people started tapping groundwater to sow high-yield seeds.

And now a new crisis is looming in the Sundarbans, a Unesco World Heritage site.

Increasing salinity in groundwater

Powerful pumps and shallow wells used for drawing groundwater are taking a toll on the only source of safe drinking water on several islands in the Sundarbans spread across the two districts of South and North 24 Parganas in West Bengal.

Some of the pumps used last year, say local farmers, were powered by five-horsepower motors that can draw as much as 10,000 litres of water in 30 minutes.

Several hundred acres are being irrigated with water drawn from depths of 50 feet and below on islands with a sizeable human population in Gosaba and Basanti assembly constituencies in the South 24 Parganas.

A number of water tables have already run dry and some are now producing saline water that can neither be consumed nor used for farming.

“On March 14, around 10 farmers from Chhoto Mollakhali came and said they tapped water from around 100 feet till these sources dried up. They changed location and dug again till around 40 feet and came to us with water samples,” Santanu Banerjee, who runs the laboratory at Tagore Society for Rural Development (TSRD) at Rangabelia, says.

“Nine out of 10 of these samples were highly saline in nature. It is a clear indication that salinity in groundwater is rising wherever fresh water reserves are being tapped,” adds Banerjee.

Image: Shutterstock
The Sundarbans
Covers parts of North and South 24 Parganas districts in India and parts of Bangladesh
Comprises more than 100 islands, seven big rivers and their numerous distributaries
Has the world’s largest mangrove forest
Home to the Royal Bengal Tiger
Declared Unesco World Heritage site in 1987
Affected areas
Basanti block with a population of 3,36,717 (according to 2011 census) and covers an area of 404.2 sq km
Gosaba block has a population of 2,46,598 (according to 2011 census) and covers an area of 296.43 sq km.
Traditional paddy that grew in brackish water
Barangeti (comes in red and white varieties)
Kotepatnai (Patnai in short)
Gheus (best for making puffed rice)

TSRD, a non-government organisation set up in 1969 to help farmers in West Bengal, Odisha and Bihar, runs the project at Rangabelia since 1975. One of its crucial jobs is to test soil and water samples for salinity.

There is no official record to show how much land in Gosaba and Basanti is being irrigated with fresh water but local farmers claim that groundwater is being used in around 350 acres at Chhoto Mollakhali and 380 acres at Bali island.

At Kumirmari, where people are still waiting for electricity, roads and basic amenities, an estimated 380 acres of land is being irrigated with groundwater tapped with shallow pumps powered by generators.

Sensing the danger, Tapan Mondal, a third-generation farmer at Kumirmari, has saved a boxful of pre-Green Revolution era paddy seeds with the names and characteristics of each variety written in bold.

“Seeds like these saved people after Aila,” he points out. “But once the brackish water receded and successive monsoons washed away the salt on the soil surface, farmers started sowing high-yielding and even hybrid seeds to recover losses,” Mondal adds.

“Villagers are getting shallow pumps on hire to make some money. An acute water crisis is going to hit the Sundarbans very soon,” Thakurpada Mondal, a farmer at Rangabelia, says.

Anil Dey, a senior TSRD field worker, says salinity in the rivers that dissect the delta and flow into the Bay of Bengal has risen because of climate change.

“But nature can’t be blamed for the depletion of groundwater reserves. As we speak, there is no natural source of drinking water within three kilometres of our camp office at Bharatgarh in Basanti. There are similar spots on Bali island,” he adds.

Govt steps in

The crisis has not gone unnoticed in the corridors of power and action is being taken, say officials in the state water resource department.

The state government, which allows farmers to use groundwater to improve production in drought-prone districts, was recently informed by the Central Ground Water Board that water level has receded to a “semi-critical” level in more than 60 blocks spread across West Bengal.

Some of these blocks are in the South and North 24 Parganas districts that are not drought-prone at all. In 2011, the number of these “semi-critical” blocks stood at 53.

“The government has taken note and decided to impose a restriction on the use of powerful pumps. Farmers will have to seek the state’s permission to draw groundwater,” a water resources department official, who is not authorised to speak to the media, says.

Need for more steps

Experts, however, feel that restricting the use of shallow pumps alone will not save the precious groundwater reserves.

Asish Kumar Ghosh, a former director of Zoological Survey of India and a Fullbright scholar who retired 20 years ago, was one of the men to show the Sundarbans farmers how to survive the curse of nature.

“When I landed in the Sundarbans after Aila, only five farmers volunteered to experiment with traditional paddy that once grew in brackish water. But getting old seeds that would germinate was the bigger challenge,” says the octogenarian at his south Kolkata residence that also houses the Centre for Environment and Development.

Ghosh, whose research papers on food security, environment and climate change have been published in 10 countries, including the UK, USA, Japan and Russia, founded the centre to encourage young researchers.

“Dr Debal Dey, who has worked in this field for 20 years and set up seed banks in 10 states, helped us. So did the National Institute for Rural Development, Hyderabad. The paddy we produced in the first two years was saved for seeds. Eventually, farmers in five blocks joined the project,” says Ghosh.

A seed bank started functioning in less than five years after Aila, which were given free of cost but on the condition that whoever took them had to return twice the amount after harvest.

“The central government must set up seed banks across the nation and encourage farmers to grow crops that can withstand the effects of climate change. Potable water will get more and more scarce in the coming years,” Ghosh warns.

Turning the tide

TSRD is trying to influence farming habits and counter the water crisis in Basanti and Gosaba.

“One of our main objectives is to discourage farmers from sowing hybrid paddy and promote vegetables and lentils, such as grass pea, that require minimum water. In 2016-17, farmers in 14 villages harvested grass pea,” Rabindra Nath Mondal, a coordinator at TSRD, says.

It has received aid from foreign agencies. Its grass pea project is being funded by OCP Foundation of Morocco that focuses on community development and International Center for Agricultural Research in the Dry Areas (ICARDA), a global research-for-development organisation based in Lebanon.

First Published: Mar 22, 2018 16:53 IST